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51. CUBES: the Cassegrain U-band Efficient Spectrograph

Author: Evans, Christopher J., Bryant, Julia J., Motohara, Kentaro, Cristiani, S., Alcalá, J. M., Alencar, S. H. P., Balashev, S., Bastian, N., Barbuy, B., Battino, U., Calcines, A., Calderone, G., Cambianica, P., Carini, R., Carter, B., Cassisi, S., Castilho, B., Cescutti, G., Christlieb, N., Cirami, R., Coretti, I., Cooke, R. J., Covino, S., Cremonese, G., Cunha, K., Cupani, G., da Silva, A., De Caprio, V., De Cia, A., Dekker, H., D'Elia, V., de Silva, G., Diaz, M. P., Di Marcantonio, P., D'Auria, D., D'Odorico, V., Fitzsimmons, A., Ernandes, H., Evans, C., Franchini, M., Genoni, M., Gänsicke, B., Giribaldi, R. E., Gneiding, C., Grazian, A., Hansen, C. J., La Forgia, F., Landoni, M., Lazzarin, M., Lunney, D., Maciel, W. J., Marcolino, W., Marconi, M., Migliorini, A., Miller, C., Noterdaeme, P., Opitom, C., Pariani, G., Pilecki, B., Piranomonte, S., Quirrenbach, A., Redaelli, E. M. A., Pereira, C., Randich, S., Rossi, S., Sanchez-Janssen, R., Seifert, W., Smiljanic, R., Snodgrass, C., Stilz, I., Stürmer, J., Vanzella, E., Ventura, P., Verducci, O., Waring, C., Watson, S., Wells, M., Wright, D., Zafar, T., and Zanutta, A.
Published: 2022
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52. Pluto's lower atmosphere and pressure evolution from ground-based stellar occultations, 1988-2016

Author: Meza, E, Sicardy, B, Assafin, M, Ortiz, JL, Bertrand, T, Lellouch, E, Desmars, J, Forget, F, Bérard, D, Doressoundiram, A, Lecacheux, J, Oliveira, JM, Roques, F, Widemann, T, Colas, F, Vachier, F, Renner, S, Leiva, R, Braga-Ribas, F, Benedetti-Rossi, G, Camargo, JIB, Dias-Oliveira, A, Morgado, B, Gomes-Júnior, AR, Vieira-Martins, R, Behrend, R, Tirado, AC, Duffard, R, Morales, N, Santos-Sanz, P, Jelínek, M, Cunniffe, R, Querel, R, Harnisch, M, Jansen, R, Pennell, A, Todd, S, Ivanov, VD, Opitom, C, Gillon, M, Jehin, E, Manfroid, J, Pollock, J, Reichart, DE, Haislip, JB, Ivarsen, KM, LaCluyze, AP, Maury, A, Gil-Hutton, R, Dhillon, V, Littlefair, S, Marsh, T, Veillet, C, Bath, K-L, Beisker, W, Bode, H-J, Kretlow, M, Herald, D, Gault, D, Kerr, S, Pavlov, H, Faragó, O, Klös, O, Frappa, E, Lavayssière, M, Cole, AA, Giles, AB, Greenhill, JG, Hill, KM, Buie, MW, Olkin, CB, Young, EF, Young, LA, Wasserman, LH, Devogèle, M, French, RG, Bianco, FB, Marchis, F, Brosch, N, Kaspi, S, Polishook, D, Manulis, I, Larbi, MAM, Benkhaldoun, Z, Daassou, A, Azhari, YE, Moulane, Y, Broughton, J, Milner, J, Dobosz, T, Bolt, G, Lade, B, Gilmore, A, Kilmartin, P, Allen, WH, Graham, PB, Loader, B, McKay, G, Talbot, J, Parker, S, Abe, L, Bendjoya, P, Rivet, J-P, Vernet, D, Fabrizio, LD, Lorenzi, V, Magazzù, A, Molinari, E, Gazeas, K, Tzouganatos, L, Carbognani, A, Bonnoli, G, Marchini, A, Leto, G, Sanchez, RZ, Mancini, L, Kattentidt, B, Dohrmann, M, Guhl, K, Rothe, W, Walzel, K, Wortmann, G, Eberle, A, Hampf, D, Ohlert, J, Krannich, G, Murawsky, G, Gährken, B, Gloistein, D, Alonso, S, Román, A, Communal, J-E, Jabet, F, Visscher, SD, Sérot, J, Janik, T, Moravec, Z, Machado, P, Selva, A, Perelló, C, Rovira, J, Conti, M, Papini, R, Salvaggio, F, Noschese, A, Tsamis, V, Tigani, K, Barroy, P, Irzyk, M, Neel, D, Godard, JP, Lanoiselée, D, Sogorb, P, Vérilhac, D, Bretton, M, Signoret, F, Ciabattari, F, Naves, R, Boutet, M, Queiroz, JD, Lindner, P, Lindner, K, Enskonatus, P, Dangl, G, Tordai, T, Eichler, H, Hattenbach, J, Peterson, C, Molnar, LA, and Howell, RR
Subjects: Earth and Planetary Astrophysics (astro-ph.EP), FOS: Physical sciences, Astrophysics - Earth and Planetary Astrophysics
Abstract: Context. Pluto's tenuous nitrogen (N2) atmosphere undergoes strong seasonal effects due to high obliquity and orbital eccentricity, and has been recently (July 2015) observed by the New Horizons spacecraft. Goals are (i) construct a well calibrated record of the seasonal evolution of surface pressure on Pluto and (ii) constrain the structure of the lower atmosphere using a central flash observed in 2015. Method: eleven stellar occultations by Pluto observed between 2002 and 2016 are used to retrieve atmospheric profiles (density, pressure, temperature) between $\sim$5 km and $\sim$380 km altitude levels (i.e. pressures from about 10 microbar to 10 nanobar). Results: (i) Pressure has suffered a monotonic increase from 1988 to 2016, that is compared to a seasonal volatile transport model, from which tight constraints on a combination of albedo and emissivity of N2 ice are derived; (ii) A central flash observed on 2015 June 29 is consistent with New Horizons REX profiles, provided that (a) large diurnal temperature variations (not expected by current models) occur over Sputnik Planitia and/or (b) hazes with tangential optical depth of about 0.3 are present at 4-7 km altitude levels and/or (c) the nominal REX density values are overestimated by an implausibly large factor of about 20% and/or (d) higher terrains block part of the flash in the Charon facing hemisphere., 21 pages, 11 figures
Published: 2019

53. Lower atmosphere and pressure evolution on Pluto from ground-based stellar occultations, 1988-2016

Author: Meza, E. Sicardy, B. Assafin, M. Ortiz, J.L. Bertrand, T. Lellouch, E. Desmars, J. Forget, F. Bérard, D. Doressoundiram, A. Lecacheux, J. Marques Oliveira, J. Roques, F. Widemann, T. Colas, F. Vachier, F. Renner, S. Leiva, R. Braga-Ribas, F. Benedetti-Rossi, G. Camargo, J.I.B. Dias-Oliveira, A. Morgado, B. Gomes-Júnior, A.R. Vieira-Martins, R. Behrend, R. Castro Tirado, A. Duffard, R. Morales, N. Santos-Sanz, P. Jelínek, M. Cunniffe, R. Querel, R. Harnisch, M. Jansen, R. Pennell, A. Todd, S. Ivanov, V.D. Opitom, C. Gillon, M. Jehin, E. Manfroid, J. Pollock, J. Reichart, D.E. Haislip, J.B. Ivarsen, K.M. LaCluyze, A.P. Maury, A. Gil-Hutton, R. Dhillon, V. Littlefair, S. Marsh, T. Veillet, C. Bath, K.-L. Beisker, W. Bode, H.-J. Kretlow, M. Herald, D. Gault, D. Kerr, S. Pavlov, H. Faragó, O. Klös, O. Frappa, E. Lavayssière, M. Cole, A.A. Giles, A.B. Greenhill, J.G. Hill, K.M. Buie, M.W. Olkin, C.B. Young, E.F. Young, L.A. Wasserman, L.H. Devogèle, M. French, R.G. Bianco, F.B. Marchis, F. Brosch, N. Kaspi, S. Polishook, D. Manulis, I. Ait Moulay Larbi, M. Benkhaldoun, Z. Daassou, A. El Azhari, Y. Moulane, Y. Broughton, J. Milner, J. Dobosz, T. Bolt, G. Lade, B. Gilmore, A. Kilmartin, P. Allen, W.H. Graham, P.B. Loader, B. McKay, G. Talbot, J. Parker, S. Abe, L. Bendjoya, P. Rivet, J.-P. Vernet, D. Di Fabrizio, L. Lorenzi, V. Magazzú, A. Molinari, E. Gazeas, K. Tzouganatos, L. Carbognani, A. Bonnoli, G. Marchini, A. Leto, G. Zanmar Sanchez, R. Mancini, L. Kattentidt, B. Dohrmann, M. Guhl, K. Rothe, W. Walzel, K. Wortmann, G. Eberle, A. Hampf, D. Ohlert, J. Krannich, G. Murawsky, G. Gährken, B. Gloistein, D. Alonso, S. Román, A. Communal, J.-E. Jabet, F. DeVisscher, S. Sérot, J. Janik, T. Moravec, Z. MacHado, P. Selva, A. Perelló, C. Rovira, J. Conti, M. Papini, R. Salvaggio, F. Noschese, A. Tsamis, V. Tigani, K. Barroy, P. Irzyk, M. Neel, D. Godard, J.P. Lanoiselée, D. Sogorb, P. Vérilhac, D. Bretton, M. Signoret, F. Ciabattari, F. Naves, R. Boutet, M. De Queiroz, J. Lindner, P. Lindner, K. Enskonatus, P. Dangl, G. Tordai, T. Eichler, H. Hattenbach, J. Peterson, C. Molnar, L.A. Howell, R.R.
Abstract: Context. The tenuous nitrogen (N2) atmosphere on Pluto undergoes strong seasonal effects due to high obliquity and orbital eccentricity, and has recently (July 2015) been observed by the New Horizons spacecraft. Aims. The main goals of this study are (i) to construct a well calibrated record of the seasonal evolution of surface pressure on Pluto and (ii) to constrain the structure of the lower atmosphere using a central flash observed in 2015. Methods. Eleven stellar occultations by Pluto observed between 2002 and 2016 are used to retrieve atmospheric profiles (density, pressure, temperature) between altitude levels of ∼5 and ∼380 km (i.e. pressures from ∼10 μbar to 10 nbar). Results. (i) Pressure has suffered a monotonic increase from 1988 to 2016, that is compared to a seasonal volatile transport model, from which tight constraints on a combination of albedo and emissivity of N2 ice are derived. (ii) A central flash observed on 2015 June 29 is consistent with New Horizons REX profiles, provided that (a) large diurnal temperature variations (not expected by current models) occur over Sputnik Planitia; and/or (b) hazes with tangential optical depth of ∼0.3 are present at 4-7 km altitude levels; and/or (c) the nominal REX density values are overestimated by an implausibly large factor of ∼20%; and/or (d) higher terrains block part of the flash in the Charon facing hemisphere. © E. Meza et al. 2019.
Published: 2019

54. Search for water outgassing of (1) Ceres near perihelion

Author: Rousselot, P., Opitom, C., Jehin, E., Hutsemékers, D., Manfroid, J., Villarreal, M. N., Li, J. -Y, Castillo-Rogez, J., Russell, C. T., Vernazza, P., Marsset, M., Roth, Lorenz, Dumas, C., Yang, B., Prettyman, T. H., Mousis, O., Rousselot, P., Opitom, C., Jehin, E., Hutsemékers, D., Manfroid, J., Villarreal, M. N., Li, J. -Y, Castillo-Rogez, J., Russell, C. T., Vernazza, P., Marsset, M., Roth, Lorenz, Dumas, C., Yang, B., Prettyman, T. H., and Mousis, O.
Abstract: Context. (1) Ceres is the largest body in the main asteroid belt and one of the most intriguing objects in the solar system, in part because of the discovery of water outgassing by the Herschel Space Observatory (HSO) and its still-debated origin. Ceres was the target of NASA's Dawn spacecraft for 3.5 yr, which achieved a detailed characterization of the dwarf planet. The possible influence of the local flux of solar energetic particles (SEP) on the production of a Cerean exosphere and water vapor has been suggested, in addition to the sublimation of water ice that depends on the temperature, meaning the heliocentric distance. Aims. We used the opportunity of both the perihelion passage of (1) Ceres in April 2018, and the presence of Dawn in its vicinity (for measuring the SEP flux in real time) to check the influence of heliocentric distance and SEP flux on water outgassing. Methods. We searched for OH emission lines near the limb of Ceres in the near-UV with the UVES spectrograph mounted on the 8-m ESO Very Large Telescope. Two spectra were recorded when Ceres was close to its perihelion, in February 2018, and with Dawn spacecraft orbiting Ceres. It was possible to simultaneously measure energetic particles around Ceres at the time of our observations. Results. Our observations did not permit detection of OH emission lines to a very high sensitivity level. This level is estimated to correspond to a global water production rate of QH2O ∼ 2 × 1026 molecules s-1, similar to the water production rate derived from HSO observations. The solar energetic particles flux measured around Ceres was negligible at the time of these observations. Conclusions. Our observations support the idea that heliocentric distance (i.e., the sublimation of water ice) does not play a major role in the water emission from Ceres. This production rate could be either related to SEP events or to other mechanisms, possibly of endogenic origin., QC 20191029
Published: 2019
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55. The Trans-Neptunian Object (84922) 2003 VS2 through Stellar Occultations

Author: Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (Brasil), European Research Council, European Commission, Ministerio de Economía y Competitividad (España), Junta de Andalucía, Ministerio de Ciencia, Innovación y Universidades (España), Conselho Nacional de Desenvolvimento Científico e Tecnológico (Brasil), Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro, Fonds de la Recherche Scientifique (Fédération Wallonie-Bruxelles), Benedetti-Rossi, G, Santos Sanz, Pablo, Ortiz, José Luis, Assafin, M., Sicardy, B, Morales, Nicolás, Vieira-Martins, Roberto, Duffard, René D., Braga-Ribas, F., Rommel, F.L, Camargo, J.I.B., Desmars, J., Colas, A.F, Vachier, F, Alvarez-Candal, A., Fernández-Valenzuela, E, Almenares, L, Artola, R, Baum, T.-P, Behrend, R, Bérard, D, Bianco, F.B, Brosch, N, Ceretta, A, Colazo, C.A, Gomes-Junior, A.R, Ivanov, Valentin D., Jehin, E, Kaspi, S, Lecacheux, J., Maury, A., Melia, R, Moindrot, S, Morgado, B., Opitom, C, Peyrot, A., Pollock, J, Pratt, A, Roland, S, Spagnotto, J, Tancredi, G, Teng, J.-P, Cacella, P, Emilio, M, Feys, F, Gil-Hutton, Ricardo A., Jacques, C, Machado, D.I, Malacarne, M, Manulis, I, Milone, A.C, Rojas, G, Sfair, R., Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (Brasil), European Research Council, European Commission, Ministerio de Economía y Competitividad (España), Junta de Andalucía, Ministerio de Ciencia, Innovación y Universidades (España), Conselho Nacional de Desenvolvimento Científico e Tecnológico (Brasil), Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro, Fonds de la Recherche Scientifique (Fédération Wallonie-Bruxelles), Benedetti-Rossi, G, Santos Sanz, Pablo, Ortiz, José Luis, Assafin, M., Sicardy, B, Morales, Nicolás, Vieira-Martins, Roberto, Duffard, René D., Braga-Ribas, F., Rommel, F.L, Camargo, J.I.B., Desmars, J., Colas, A.F, Vachier, F, Alvarez-Candal, A., Fernández-Valenzuela, E, Almenares, L, Artola, R, Baum, T.-P, Behrend, R, Bérard, D, Bianco, F.B, Brosch, N, Ceretta, A, Colazo, C.A, Gomes-Junior, A.R, Ivanov, Valentin D., Jehin, E, Kaspi, S, Lecacheux, J., Maury, A., Melia, R, Moindrot, S, Morgado, B., Opitom, C, Peyrot, A., Pollock, J, Pratt, A, Roland, S, Spagnotto, J, Tancredi, G, Teng, J.-P, Cacella, P, Emilio, M, Feys, F, Gil-Hutton, Ricardo A., Jacques, C, Machado, D.I, Malacarne, M, Manulis, I, Milone, A.C, Rojas, G, and Sfair, R.
Abstract: We present results from three world-wide campaigns that resulted in the detections of two single-chord and one multi-chord stellar occultations by the plutino object (84922) 2003 VS2. From the single-chord occultations in 2013 and 2014 we obtained accurate astrometric positions for the object, while from the multi-chord occultation on 2014 November 7, we obtained the parameters of the best-fitting ellipse to the limb of the body at the time of occultation. We also obtained short-term photometry data for the body in order to derive its rotational phase during the occultation. The rotational light curve present a peak-to-peak amplitude of 0.141 ± 0.009 mag. This allows us to reconstruct the 3D shape of the body, with principal semi-axes of a = 313.8 ± 7.1 km, b = 265.5- + 9.8 8.8 km, and c = 247.3- + 43.6 26.6 km, which is not consistent with a Jacobi triaxial equilibrium figure. The derived spherical volume equivalent diameter of 548.3- + 44.6 29.5 km is about 5% larger than the radiometric diameter of 2003 VS2 derived from Herschel data of 523 ± 35 km, but still compatible with it within error bars. From those results we can also derive the geometric albedo (0.123- + 0.014 0.015) and, under the assumption that the object is a Maclaurin spheroid, the density r = 1400- + 300 1000 for the plutino. The disappearances and reappearances of the star during the occultations do not show any compelling evidence for a global atmosphere considering a pressure upper limit of about 1 microbar for a pure nitrogen atmosphere, nor secondary features (e.g., rings or satellite) around the main body. © 2019. The American Astronomical Society. All rights reserved.
Published: 2019

56. The Trans-Neptunian Object (84922) 2003 VS2 through Stellar Occultations

Author: Benedetti-Rossi, Gustavo, primary, Santos-Sanz, P., additional, Ortiz, J. L., additional, Assafin, M., additional, Sicardy, B., additional, Morales, N., additional, Vieira-Martins, R., additional, Duffard, R., additional, Braga-Ribas, F., additional, Rommel, F. L., additional, Camargo, J. I. B., additional, Desmars, J., additional, Colas, A. F., additional, Vachier, F., additional, Alvarez-Candal, A., additional, Fernández-Valenzuela, E., additional, Almenares, L., additional, Artola, R., additional, Baum, T.-P., additional, Behrend, R., additional, Bérard, D., additional, Bianco, F. B., additional, Brosch, N., additional, Ceretta, A., additional, Colazo, C. A., additional, Gomes-Junior, A. R., additional, Ivanov, V. D., additional, Jehin, E., additional, Kaspi, S., additional, Lecacheux, J., additional, Maury, A., additional, Melia, R., additional, Moindrot, S., additional, Morgado, B., additional, Opitom, C., additional, Peyrot, A., additional, Pollock, J., additional, Pratt, A., additional, Roland, S., additional, Spagnotto, J., additional, Tancredi, G., additional, Teng, J.-P., additional, Cacella, P., additional, Emilio, M., additional, Feys, F., additional, Gil-Hutton, R., additional, Jacques, C., additional, Machado, D. I., additional, Malacarne, M., additional, Manulis, I., additional, Milone, A. C., additional, Rojas, G., additional, and Sfair, R., additional
Published: 2019
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57. First observations of an outbursting comet with the MUSE integral-field spectrograph

Author: Opitom, C., primary, Yang, B., additional, Selman, F., additional, and Reyes, C., additional
Published: 2019
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58. Search for water outgassing of (1) Ceres near perihelion

Author: Rousselot, P., primary, Opitom, C., additional, Jehin, E., additional, Hutsemékers, D., additional, Manfroid, J., additional, Villarreal, M. N., additional, Li, J.-Y., additional, Castillo-Rogez, J., additional, Russell, C. T., additional, Vernazza, P., additional, Marsset, M., additional, Roth, L., additional, Dumas, C., additional, Yang, B., additional, Prettyman, T. H., additional, and Mousis, O., additional
Published: 2019
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59. Lower atmosphere and pressure evolution on Pluto from ground-based stellar occultations, 1988–2016

Author: Meza, E., primary, Sicardy, B., additional, Assafin, M., additional, Ortiz, J. L., additional, Bertrand, T., additional, Lellouch, E., additional, Desmars, J., additional, Forget, F., additional, Bérard, D., additional, Doressoundiram, A., additional, Lecacheux, J., additional, Oliveira, J. Marques, additional, Roques, F., additional, Widemann, T., additional, Colas, F., additional, Vachier, F., additional, Renner, S., additional, Leiva, R., additional, Braga-Ribas, F., additional, Benedetti-Rossi, G., additional, Camargo, J. I. B., additional, Dias-Oliveira, A., additional, Morgado, B., additional, Gomes-Júnior, A. R., additional, Vieira-Martins, R., additional, Behrend, R., additional, Tirado, A. Castro, additional, Duffard, R., additional, Morales, N., additional, Santos-Sanz, P., additional, Jelínek, M., additional, Cunniffe, R., additional, Querel, R., additional, Harnisch, M., additional, Jansen, R., additional, Pennell, A., additional, Todd, S., additional, Ivanov, V. D., additional, Opitom, C., additional, Gillon, M., additional, Jehin, E., additional, Manfroid, J., additional, Pollock, J., additional, Reichart, D. E., additional, Haislip, J. B., additional, Ivarsen, K. M., additional, LaCluyze, A. P., additional, Maury, A., additional, Gil-Hutton, R., additional, Dhillon, V., additional, Littlefair, S., additional, Marsh, T., additional, Veillet, C., additional, Bath, K.-L., additional, Beisker, W., additional, Bode, H.-J., additional, Kretlow, M., additional, Herald, D., additional, Gault, D., additional, Kerr, S., additional, Pavlov, H., additional, Faragó, O., additional, Klös, O., additional, Frappa, E., additional, Lavayssière, M., additional, Cole, A. A., additional, Giles, A. B., additional, Greenhill, J. G., additional, Hill, K. M., additional, Buie, M. W., additional, Olkin, C. B., additional, Young, E. F., additional, Young, L. A., additional, Wasserman, L. H., additional, Devogèle, M., additional, French, R. G., additional, Bianco, F. B., additional, Marchis, F., additional, Brosch, N., additional, Kaspi, S., additional, Polishook, D., additional, Manulis, I., additional, Ait Moulay Larbi, M., additional, Benkhaldoun, Z., additional, Daassou, A., additional, El Azhari, Y., additional, Moulane, Y., additional, Broughton, J., additional, Milner, J., additional, Dobosz, T., additional, Bolt, G., additional, Lade, B., additional, Gilmore, A., additional, Kilmartin, P., additional, Allen, W. H., additional, Graham, P. B., additional, Loader, B., additional, McKay, G., additional, Talbot, J., additional, Parker, S., additional, Abe, L., additional, Bendjoya, Ph., additional, Rivet, J.-P., additional, Vernet, D., additional, Di Fabrizio, L., additional, Lorenzi, V., additional, Magazzú, A., additional, Molinari, E., additional, Gazeas, K., additional, Tzouganatos, L., additional, Carbognani, A., additional, Bonnoli, G., additional, Marchini, A., additional, Leto, G., additional, Sanchez, R. Zanmar, additional, Mancini, L., additional, Kattentidt, B., additional, Dohrmann, M., additional, Guhl, K., additional, Rothe, W., additional, Walzel, K., additional, Wortmann, G., additional, Eberle, A., additional, Hampf, D., additional, Ohlert, J., additional, Krannich, G., additional, Murawsky, G., additional, Gährken, B., additional, Gloistein, D., additional, Alonso, S., additional, Román, A., additional, Communal, J.-E., additional, Jabet, F., additional, deVisscher, S., additional, Sérot, J., additional, Janik, T., additional, Moravec, Z., additional, Machado, P., additional, Selva, A., additional, Perelló, C., additional, Rovira, J., additional, Conti, M., additional, Papini, R., additional, Salvaggio, F., additional, Noschese, A., additional, Tsamis, V., additional, Tigani, K., additional, Barroy, P., additional, Irzyk, M., additional, Neel, D., additional, Godard, J. P., additional, Lanoiselée, D., additional, Sogorb, P., additional, Vérilhac, D., additional, Bretton, M., additional, Signoret, F., additional, Ciabattari, F., additional, Naves, R., additional, Boutet, M., additional, De Queiroz, J., additional, Lindner, P., additional, Lindner, K., additional, Enskonatus, P., additional, Dangl, G., additional, Tordai, T., additional, Eichler, H., additional, Hattenbach, J., additional, Peterson, C., additional, Molnar, L. A., additional, and Howell, R. R., additional
Published: 2019
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60. High resolution optical spectroscopy of the N2-rich comet C/2016 R2 (PanSTARRS)

Author: Opitom, C., primary, Hutsemékers, D., additional, Jehin, E., additional, Rousselot, P., additional, Pozuelos, F. J., additional, Manfroid, J., additional, Moulane, Y., additional, Gillon, M., additional, and Benkhaldoun, Z., additional
Published: 2019
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61. Monitoring of the activity and composition of comets 41P/Tuttle–Giacobini–Kresak and 45P/Honda–Mrkos–Pajdusakova

Author: Moulane, Y., primary, Jehin, E., additional, Opitom, C., additional, Pozuelos, F. J., additional, Manfroid, J., additional, Benkhaldoun, Z., additional, Daassou, A., additional, and Gillon, M., additional
Published: 2018
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62. Dust modelling and a dynamical study of comet 41P/Tuttle–Giacobini–Kresak during its 2017 perihelion passage

Author: Pozuelos, F. J., primary, Jehin, E., additional, Moulane, Y., additional, Opitom, C., additional, Manfroid, J., additional, Benkhaldoun, Z., additional, and Gillon, M., additional
Published: 2018
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63. Ground-based monitoring of comet 67P/Churyumov–Gerasimenko gas activity throughout the Rosetta mission

Author: Opitom, C., primary, Snodgrass, C., additional, Fitzsimmons, A., additional, Jehin, E., additional, Manfroid, J., additional, Tozzi, G. P., additional, Faggi, S., additional, and Gillon, M., additional
Published: 2017
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64. Monitoring of comets activity and composition with the TRAPPIST-North telescope

Author: Moulane, Y, primary, Benkhaldoun, Z, additional, Jehin, E, additional, Opitom, C, additional, Gillon, M, additional, and Daassou, A, additional
Published: 2017
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65. The 67P/Churyumov–Gerasimenko observation campaign in support of the Rosetta mission

Author: Snodgrass, C., primary, A'Hearn, M. F., additional, Aceituno, F., additional, Afanasiev, V., additional, Bagnulo, S., additional, Bauer, J., additional, Bergond, G., additional, Besse, S., additional, Biver, N., additional, Bodewits, D., additional, Boehnhardt, H., additional, Bonev, B. P., additional, Borisov, G., additional, Carry, B., additional, Casanova, V., additional, Cochran, A., additional, Conn, B. C., additional, Davidsson, B., additional, Davies, J. K., additional, de León, J., additional, de Mooij, E., additional, de Val-Borro, M., additional, Delacruz, M., additional, DiSanti, M. A., additional, Drew, J. E., additional, Duffard, R., additional, Edberg, N. J. T., additional, Faggi, S., additional, Feaga, L., additional, Fitzsimmons, A., additional, Fujiwara, H., additional, Gibb, E. L., additional, Gillon, M., additional, Green, S. F., additional, Guijarro, A., additional, Guilbert-Lepoutre, A., additional, Gutiérrez, P. J., additional, Hadamcik, E., additional, Hainaut, O., additional, Haque, S., additional, Hedrosa, R., additional, Hines, D., additional, Hopp, U., additional, Hoyo, F., additional, Hutsemékers, D., additional, Hyland, M., additional, Ivanova, O., additional, Jehin, E., additional, Jones, G. H., additional, Keane, J. V., additional, Kelley, M. S. P., additional, Kiselev, N., additional, Kleyna, J., additional, Kluge, M., additional, Knight, M. M., additional, Kokotanekova, R., additional, Koschny, D., additional, Kramer, E. A., additional, López-Moreno, J. J., additional, Lacerda, P., additional, Lara, L. M., additional, Lasue, J., additional, Lehto, H. J., additional, Levasseur-Regourd, A. C., additional, Licandro, J., additional, Lin, Z. Y., additional, Lister, T., additional, Lowry, S. C., additional, Mainzer, A., additional, Manfroid, J., additional, Marchant, J., additional, McKay, A. J., additional, McNeill, A., additional, Meech, K. J., additional, Micheli, M., additional, Mohammed, I., additional, Monguió, M., additional, Moreno, F., additional, Muñoz, O., additional, Mumma, M. J., additional, Nikolov, P., additional, Opitom, C., additional, Ortiz, J. L., additional, Paganini, L., additional, Pajuelo, M., additional, Pozuelos, F. J., additional, Protopapa, S., additional, Pursimo, T., additional, Rajkumar, B., additional, Ramanjooloo, Y., additional, Ramos, E., additional, Ries, C., additional, Riffeser, A., additional, Rosenbush, V., additional, Rousselot, P., additional, Ryan, E. L., additional, Santos-Sanz, P., additional, Schleicher, D. G., additional, Schmidt, M., additional, Schulz, R., additional, Sen, A. K., additional, Somero, A., additional, Sota, A., additional, Stinson, A., additional, Sunshine, J. M., additional, Thompson, A., additional, Tozzi, G. P., additional, Tubiana, C., additional, Villanueva, G. L., additional, Wang, X., additional, Wooden, D. H., additional, Yagi, M., additional, Yang, B., additional, Zaprudin, B., additional, and Zegmott, T. J., additional
Published: 2017
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66. Dust from Comet 209P/LINEAR during its 2014 Return: Parent Body of a New Meteor Shower, the May Camelopardalids

Author: Ishiguro, M, Kuroda, D, Hanayama, H, Takahashi, J, Hasegawa, S, Sarugaku, Y, Watanabe, M, Imai, M, Goda, S, Akitaya, H, Takagi, Y, Morihana, K, Honda, S, Arai, A, Sekiguchi, K, Oasa, Y, Saito, Yoshihiko, Morokuma, T, Murata, K, Nogami, D, Nagayama, T, Yanagisawa, K, Yoshida, M, Ohta, K, Kawai, Nobuyuki, Miyaji, T, Fukushima, H, Watanabe, J.-i., Opitom, C, Jehin, E, Gillon, M, Vaubaillon, J.~J., Department of Physics and Astronomy and Center for Theoretical Physics, Seoul National University, Seoul National University [Seoul], Okayama Astrophysical Observatory ( OAO ), National Astronomical Observatory of Japan ( NAOJ ), Ishigakijima Astronomical Observatory, Nishi-Harima Astronomical Observatory, Center for Astronomy, Institute of Space and Astronautical Science ( ISAS ), Department of Cosmosciences, Hokkaido University, Hiroshima Astrophysical Science Center, Hiroshima University, Japan, Faculty of Education, Saitama University, Department of Physics [Tokyo], Tokyo Institure of Technology, Institute of Astronomy, Graduate School of Science, The University of Tokyo, Department of Astrophysics, Nagoya University, Department of astronomy, Kyoto University, Graduate School of Science and Engineering, Kagoshima University, Institut d'Astrophysique et de Géophysique [Liège], Université de Liège, Institut de Mécanique Céleste et de Calcul des Ephémérides ( IMCCE ), Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Observatoire de Paris-Université de Lille-Centre National de la Recherche Scientifique ( CNRS ), Department of Physics and Astronomy [Seoul], Seoul National University [Seoul] (SNU), Center for Theoretical Physics [Seoul], Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Okayama Astrophysical Observatory (OAO), National Astronomical Observatory of Japan (NAOJ), Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency [Sagamihara] (JAXA), Hokkaido University [Sapporo, Japan], Hiroshima University, The University of Tokyo (UTokyo), Department of Astrophysics [Nagoya], Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)
Subjects: Earth and Planetary Astrophysics (astro-ph.EP), Physics, 010504 meteorology & atmospheric sciences, Terminal velocity, Meteoroid, Comet, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Escape velocity, comets: individual: 209P/LINEAR, 01 natural sciences, comets: individual (209P/LINEAR), Jupiter, Space and Planetary Science, [SDU]Sciences of the Universe [physics], Comet nucleus, 0103 physical sciences, interplanetary medium, Meteor shower, 010303 astronomy & astrophysics, [ SDU ] Sciences of the Universe [physics], Astrophysics - Earth and Planetary Astrophysics, 0105 earth and related environmental sciences, Cosmic dust
Abstract: 著者人数: 32名, Accepted: 2014-12-11, 資料番号: SA1005017000
Published: 2015
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67. High resolution optical spectroscopy of the N2-rich comet C/2016 R2 (PanSTARRS).

Author: Opitom, C., Hutsemékers, D., Jehin, E., Rousselot, P., Pozuelos, F. J., Manfroid, J., Moulane, Y., Gillon, M., and Benkhaldoun, Z.
Subjects: *HIGH resolution spectroscopy, *COMETS, *SPECTROGRAPHS, *OPTICAL spectroscopy, *KUIPER belt, *VERY large telescopes
Abstract: Context. Early observations of comet C/2016 R2 (PanSTARRS) have shown that the composition of this comet is very peculiar. Radio observations have revealed a CO-rich and HCN-poor comet and an optical coma dominated by strong emission bands of CO+ and, more surprisingly, N2+ $\mathrm{N_2^+}$ N 2 + . Aims. The strong detection of N2+ $\mathrm{N_2^+}$ N 2 + in the coma of C/2016 R2 provided an ideal opportunity to measure the 14N∕15N isotopic ratio directly from N2+ $\mathrm{N_2^+}$ N 2 + for the first time, and to estimate the N2∕CO ratio, which is an important diagnostic to constrain formation models of planetesimals, in addition to the more general study of coma composition. Methods. We obtained high resolution spectra of the comet in February 2018 when it was at 2.8 au from the Sun. We used the UVES spectrograph of the European Southern Observatory Very Large Telescope, complemented with narrowband images obtained with the TRAPPIST telescopes. Results. We detect strong emissions from the N2+ $\mathrm{N_2^+}$ N 2 + and CO+ ions, but also CO2+ $\mathrm{CO_2^+}$ CO 2 + , emission lines from the CH radical, and much fainter emissions of the CN, C2, and C3 radicals that were not detected in previous observations of this comet. We do not detect OH or H2O+, and we derive an upper limit of the H2O+∕CO+ ratio of 0.4, implying that the comet has a low water abundance. We measure a N2+/CO+ $\mathrm{N_2^+/CO^+}$ N 2 + /CO + ratio of 0.06 ± 0.01. The non-detection of NH2 indicates that most of the nitrogen content of the comet is in N2. Together with the high N2+/CO+ $\mathrm{N_2^+/CO^+}$ N 2 + /CO + ratio, this could indicate a low formation temperature of the comet or that the comet is a fragment of a large differentiated Kuiper Belt object. The CO2+/CO+ $\mathrm{CO_2^+/CO^+}$ CO 2 + /CO + ratio is 1.1 ± 0.3. We do not detect 14N15N+ lines and can only put a lower limit on the 14N∕15N ratio (measured from N2+ $\mathrm{N_2^+}$ N 2 + ) of about 100, which is compatible with measurements of the same isotopic ratio for NH2 and CN in other comets. Finally, in addition to the [OI] and [CI] forbidden lines, we detect for the first time the forbidden nitrogen lines [NI] doublet at 519.79 and 520.03 nm in the coma of a comet. [ABSTRACT FROM AUTHOR]
Published: 2019
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68. The 2016 Feb 19 outburst of comet 67P/CG : an ESA Rosetta multi-instrument study

Author: Grun, E., Agarwal, J., Altobelli, N., Altwegg, K., Bentley, M. S., Biver, N., Della Corte, V., Edberg, Niklas J. T., Feldman, P. D., Galand, M., Geiger, B., Goetz, C., Grieger, B., Guettler, C., Henri, P., Hofstadter, M., Horanyi, M., Jehin, E., Krueger, H., Lee, S., Mannel, T., Morales, E., Mousis, O., Mueller, M., Opitom, C., Rotundi, A., Schmied, R., Schmidt, F., Sierks, H., Snodgrass, C., Soja, R. H., Sommer, M., Srama, R., Tzou, C. -Y, Vincent, J. -B, Yanamandra-Fisher, P., A'Hearn, M. F., Eriksson, Anders, Barbieri, C., Barucci, M. A., Bertaux, J. -L, Bertini, I., Burch, J., Colangeli, L., Cremonese, G., Da Deppo, V., Davidsson, Björn, Debei, S., De Cecco, M., Deller, J., Feaga, L. M., Ferrari, M., Fornasier, S., Fulle, M., Gicquel, A., Gillon, M., Green, S. F., Groussin, O., Gutierrez, P. J., Hofmann, M., Hviid, S. F., Ip, W. -H, Ivanovski, S., Jorda, L., Keller, H. U., Knight, M. M., Knollenberg, J., Koschny, D., Kramm, J. -R, Kuehrt, E., Kuppers, M., Lamy, P. L., Lara, L. M., Lazzarin, M., Lopez-Moreno, J. J., Manfroid, J., Epifani, E. Mazzotta, Marzari, F., Naletto, G., Oklay, N., Palumbo, P., Parker, J. Wm., Rickman, Hans, Rodrigo, R., Rodriguez, J., Schindhelm, E., Shi, X., Sordini, R., Steffl, A. J., Stern, S. A., Thomas, N., Tubiana, C., Weaver, H. A., Weissman, P., Zakharov, V. V., Grun, E., Agarwal, J., Altobelli, N., Altwegg, K., Bentley, M. S., Biver, N., Della Corte, V., Edberg, Niklas J. T., Feldman, P. D., Galand, M., Geiger, B., Goetz, C., Grieger, B., Guettler, C., Henri, P., Hofstadter, M., Horanyi, M., Jehin, E., Krueger, H., Lee, S., Mannel, T., Morales, E., Mousis, O., Mueller, M., Opitom, C., Rotundi, A., Schmied, R., Schmidt, F., Sierks, H., Snodgrass, C., Soja, R. H., Sommer, M., Srama, R., Tzou, C. -Y, Vincent, J. -B, Yanamandra-Fisher, P., A'Hearn, M. F., Eriksson, Anders, Barbieri, C., Barucci, M. A., Bertaux, J. -L, Bertini, I., Burch, J., Colangeli, L., Cremonese, G., Da Deppo, V., Davidsson, Björn, Debei, S., De Cecco, M., Deller, J., Feaga, L. M., Ferrari, M., Fornasier, S., Fulle, M., Gicquel, A., Gillon, M., Green, S. F., Groussin, O., Gutierrez, P. J., Hofmann, M., Hviid, S. F., Ip, W. -H, Ivanovski, S., Jorda, L., Keller, H. U., Knight, M. M., Knollenberg, J., Koschny, D., Kramm, J. -R, Kuehrt, E., Kuppers, M., Lamy, P. L., Lara, L. M., Lazzarin, M., Lopez-Moreno, J. J., Manfroid, J., Epifani, E. Mazzotta, Marzari, F., Naletto, G., Oklay, N., Palumbo, P., Parker, J. Wm., Rickman, Hans, Rodrigo, R., Rodriguez, J., Schindhelm, E., Shi, X., Sordini, R., Steffl, A. J., Stern, S. A., Thomas, N., Tubiana, C., Weaver, H. A., Weissman, P., and Zakharov, V. V.
Abstract: On 2016 Feb 19, nine Rosetta instruments serendipitously observed an outburst of gas and dust from the nucleus of comet 67P/Churyumov-Gerasimenko. Among these instruments were cameras and spectrometers ranging from UV over visible to microwave wavelengths, in situ gas, dust and plasma instruments, and one dust collector. At 09: 40 a dust cloud developed at the edge of an image in the shadowed region of the nucleus. Over the next two hours the instruments recorded a signature of the outburst that significantly exceeded the background. The enhancement ranged from 50 per cent of the neutral gas density at Rosetta to factors > 100 of the brightness of the coma near the nucleus. Dust related phenomena (dust counts or brightness due to illuminated dust) showed the strongest enhancements (factors > 10). However, even the electron density at Rosetta increased by a factor 3 and consequently the spacecraft potential changed from similar to-16 V to -20 V during the outburst. A clear sequence of events was observed at the distance of Rosetta ( 34 km from the nucleus): within 15 min the Star Tracker camera detected fast particles (similar to 25 m s(-1)) while 100 mu m radius particles were detected by the GIADA dust instrument similar to 1 h later at a speed of 6 m s(-1). The slowest were individual mm to cm sized grains observed by the OSIRIS cameras. Although the outburst originated just outside the FOV of the instruments, the source region and the magnitude of the outburst could be determined.
Published: 2016
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69. Distant activity of 67P/Churyumov-Gerasimenko in 2014: Ground-based results during the Rosetta pre-landing phase

Author: Snodgrass, C., Jehin, E., Manfroid, J., Opitom, C., Fitzsimmons, A., Tozzi, G. P., Faggi, S., Yang, B., Knight, M. M., Conn, B. C., Lister, T., Hainaut, O., Bramich, D. M., Lowry, S. C., Rożek, A., Tubiana, C., Guilbert-Lepoutre, A., Snodgrass, C., Jehin, E., Manfroid, J., Opitom, C., Fitzsimmons, A., Tozzi, G. P., Faggi, S., Yang, B., Knight, M. M., Conn, B. C., Lister, T., Hainaut, O., Bramich, D. M., Lowry, S. C., Rożek, A., Tubiana, C., and Guilbert-Lepoutre, A.
Abstract: Context. As the ESA Rosetta mission approached, orbited, and sent a lander to comet 67P/Churyumov-Gerasimenko in 2014, a large campaign of ground-based observations also followed the comet. Aims. We constrain the total activity level of the comet by photometry and spectroscopy to place Rosetta results in context and to understand the large-scale structure of the comet's coma pre-perihelion. Methods. We performed observations using a number of telescopes, but concentrate on results from the 8 m VLT and Gemini South telescopes in Chile. We use R-band imaging to measure the dust coma contribution to the comet's brightness and UV-visible spectroscopy to search for gas emissions, primarily using VLT/FORS. In addition we imaged the comet in near-infrared wavelengths (JHK) in late 2014 with Gemini-S/Flamingos-2. Results. We find that the comet was already active in early 2014 at heliocentric distances beyond 4 au. The evolution of the total activity (measured by dust) followed previous predictions. No gas emissions were detected despite sensitive searches. Conclusions. The comet maintains a similar level of activity from orbit to orbit, and is in that sense predictable, meaning that Rosetta results correspond to typical behaviour for this comet. The gas production (for CN at least) is highly asymmetric with respect to perihelion, as our upper limits are below the measured production rates for similar distances post-perihelion in previous orbits. ¬© ESO, 2016.
Published: 2016

70. The 2016 Feb 19 outburst of comet 67P/CG: an ESA Rosetta multi-instrument study

Author: Grün, E., primary, Agarwal, J., additional, Altobelli, N., additional, Altwegg, K., additional, Bentley, M. S., additional, Biver, N., additional, Della Corte, V., additional, Edberg, N., additional, Feldman, P. D., additional, Galand, M., additional, Geiger, B., additional, Götz, C., additional, Grieger, B., additional, Güttler, C., additional, Henri, P., additional, Hofstadter, M., additional, Horanyi, M., additional, Jehin, E., additional, Krüger, H., additional, Lee, S., additional, Mannel, T., additional, Morales, E., additional, Mousis, O., additional, Müller, M., additional, Opitom, C., additional, Rotundi, A., additional, Schmied, R., additional, Schmidt, F., additional, Sierks, H., additional, Snodgrass, C., additional, Soja, R. H., additional, Sommer, M., additional, Srama, R., additional, Tzou, C.-Y., additional, Vincent, J.-B., additional, Yanamandra-Fisher, P., additional, A'Hearn, M. F., additional, Erikson, A. I., additional, Barbieri, C., additional, Barucci, M. A., additional, Bertaux, J.-L., additional, Bertini, I., additional, Burch, J., additional, Colangeli, L., additional, Cremonese, G., additional, Da Deppo, V., additional, Davidsson, B., additional, Debei, S., additional, De Cecco, M., additional, Deller, J., additional, Feaga, L. M., additional, Ferrari, M., additional, Fornasier, S., additional, Fulle, M., additional, Gicquel, A., additional, Gillon, M., additional, Green, S. F., additional, Groussin, O., additional, Gutiérrez, P. J., additional, Hofmann, M., additional, Hviid, S. F., additional, Ip, W.-H., additional, Ivanovski, S., additional, Jorda, L., additional, Keller, H. U., additional, Knight, M. M., additional, Knollenberg, J., additional, Koschny, D., additional, Kramm, J.-R., additional, Kührt, E., additional, Küppers, M., additional, Lamy, P. L., additional, Lara, L. M., additional, Lazzarin, M., additional, Lòpez-Moreno, J. J., additional, Manfroid, J., additional, Epifani, E. Mazzotta, additional, Marzari, F., additional, Naletto, G., additional, Oklay, N., additional, Palumbo, P., additional, Parker, J. Wm., additional, Rickman, H., additional, Rodrigo, R., additional, Rodrìguez, J., additional, Schindhelm, E., additional, Shi, X., additional, Sordini, R., additional, Steffl, A. J., additional, Stern, S. A., additional, Thomas, N., additional, Tubiana, C., additional, Weaver, H. A., additional, Weissman, P., additional, Zakharov, V. V., additional, and Taylor, M. G. G. T., additional
Published: 2016
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71. Long-term activity and outburst of comet C/2013 A1 (Siding Spring) from narrow-band photometry and long-slit spectroscopy

Author: Opitom, C., primary, Guilbert-Lepoutre, A., additional, Jehin, E., additional, Manfroid, J., additional, Hutsemékers, D., additional, Gillon, M., additional, Magain, P., additional, Roberts-Borsani, G., additional, and Witasse, O., additional
Published: 2016
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72. The dust environment of comet 67P/Churyumov-Gerasimenko from Rosetta OSIRIS and VLT observations in the 4.5 to 2.9 AU heliocentric distance range inbound

Author: Moreno, F., primary, Snodgrass, C., additional, Hainaut, O., additional, Tubiana, C., additional, Sierks, H., additional, Barbieri, C., additional, Lamy, P. L., additional, Rodrigo, R., additional, Koschny, D., additional, Rickman, H., additional, Keller, H. U., additional, Agarwal, J., additional, A’Hearn, M. F., additional, Barucci, M. A., additional, Bertaux, J.-L., additional, Bertini, I., additional, Besse, S., additional, Bodewits, D., additional, Cremonese, G., additional, Da Deppo, V., additional, Davidsson, B., additional, Debei, S., additional, De Cecco, M., additional, Ferri, F., additional, Fornasier, S., additional, Fulle, M., additional, Groussin, O., additional, Gutiérrez, P. J., additional, Gutiérrez-Marques, P., additional, Güttler, C., additional, Hviid, S. F., additional, Ip, W.-H., additional, Jorda, L., additional, Knollenberg, J., additional, Kovacs, G., additional, Kramm, J.-R., additional, Kührt, E., additional, Küppers, M., additional, Lara, L. M., additional, Lazzarin, M., additional, López-Moreno, J. J., additional, Marzari, F., additional, Mottola, S., additional, Naletto, G., additional, Oklay, N., additional, Pajola, M., additional, Thomas, N., additional, Vincent, J. B., additional, Della Corte, V., additional, Fitzsimmons, A., additional, Faggi, S., additional, Jehin, E., additional, Opitom, C., additional, and Tozzi, G.-P., additional
Published: 2016
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73. Evidence that Pluto's atmosphere does not collapse from occultations including the 2013 May 04 event

Author: National Aeronautics and Space Administration (US), Olkin, C.B., Young, L.A., Borncamp, D., Pickles, A., Sicardy, B., Assafin, M., Bianco, F.B., Buie, M.W., De Oliveira, A.D., Gillon, M., French, R.G., Ramos Gomes, A., Jehin, E., Morales, N., Opitom, C., Ortiz, José Luis, Maury, A., Norbury, M., Braga-Ribas, F., Smith, R., Wasserman, L.H., Young, E.F., Zacharias, M., Zacharias, N., National Aeronautics and Space Administration (US), Olkin, C.B., Young, L.A., Borncamp, D., Pickles, A., Sicardy, B., Assafin, M., Bianco, F.B., Buie, M.W., De Oliveira, A.D., Gillon, M., French, R.G., Ramos Gomes, A., Jehin, E., Morales, N., Opitom, C., Ortiz, José Luis, Maury, A., Norbury, M., Braga-Ribas, F., Smith, R., Wasserman, L.H., Young, E.F., Zacharias, M., and Zacharias, N.
Abstract: © 2014 The Authors. Combining stellar occultation observations probing Pluto's atmosphere from 1988 to 2013, and models of energy balance between Pluto's surface and atmosphere, we find the preferred models are consistent with Pluto retaining a collisional atmosphere throughout its 248-year orbit. The occultation results show an increasing atmospheric pressure with time in the current epoch, a trend present only in models with a high thermal inertia and a permanent N2 ice cap at Pluto's north rotational pole.
Published: 2015

74. TRAPPIST photometry and imaging monitoring of comet C/2013 R1 (Lovejoy): Implications for the origin of daughter species

Author: Opitom, C., primary, Jehin, E., additional, Manfroid, J., additional, Hutsemékers, D., additional, Gillon, M., additional, and Magain, P., additional
Published: 2015
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75. PLUTO’s ATMOSPHERE FROM STELLAR OCCULTATIONS IN 2012 AND 2013

Author: Dias-Oliveira, A., primary, Sicardy, B., additional, Lellouch, E., additional, Vieira-Martins, R., additional, Assafin, M., additional, Camargo, J. I. B., additional, Braga-Ribas, F., additional, Gomes-Júnior, A. R., additional, Benedetti-Rossi, G., additional, Colas, F., additional, Decock, A., additional, Doressoundiram, A., additional, Dumas, C., additional, Emilio, M., additional, Fabrega Polleri, J., additional, Gil-Hutton, R., additional, Gillon, M., additional, Girard, J. H., additional, Hau, G. K. T., additional, Ivanov, V. D., additional, Jehin, E., additional, Lecacheux, J., additional, Leiva, R., additional, Lopez-Sisterna, C., additional, Mancini, L., additional, Manfroid, J., additional, Maury, A., additional, Meza, E., additional, Morales, N., additional, Nagy, L., additional, Opitom, C., additional, Ortiz, J. L., additional, Pollock, J., additional, Roques, F., additional, Snodgrass, C., additional, Soulier, J. F., additional, Thirouin, A., additional, Vanzi, L., additional, Widemann, T., additional, Reichart, D. E., additional, LaCluyze, A. P., additional, Haislip, J. B., additional, Ivarsen, K. M., additional, Dominik, M., additional, Jørgensen, U., additional, and Skottfelt, J., additional
Published: 2015
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76. TRAPPIST monitoring of comet C/2012 F6 (Lemmon)

Author: Opitom, C., primary, Jehin, E., additional, Manfroid, J., additional, Hutsemékers, D., additional, Gillon, M., additional, and Magain, P., additional
Published: 2015
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77. Continued activity in P/2013 P5 PANSTARRS: Unexpected comet, rotational break-up, or rubbing binary asteroid?

Author: Hainaut, O.R., Boehnhardt, H., Snodgrass, C., Meech, K.J., Deller, Jakob, Gillon, M., Jehin, E., Kuehrt, E., Lowry, S.C., Manfroid, J., Micheli, M., Mottola, S., Opitom, C., Vincent, J.-B., Wainscoat, R., Hainaut, O.R., Boehnhardt, H., Snodgrass, C., Meech, K.J., Deller, Jakob, Gillon, M., Jehin, E., Kuehrt, E., Lowry, S.C., Manfroid, J., Micheli, M., Mottola, S., Opitom, C., Vincent, J.-B., and Wainscoat, R.
Abstract: The object P/2013 P5 PANSTARRS was discovered in August 2013, displaying a cometary tail, but its orbital elements indicated that it was a typical member of the inner asteroid main belt. We monitored the object from 2013 August 30 until 2013 October 05 using the CFHT 3.6 m telescope (Mauna Kea, HI), the NTT (ESO, La Silla), the CA 1.23 m telescope (Calar Alto), the Perkins 1.8m (Lowell) and the 0.6 m TRAPPIST telescope (La Silla). We measured its nuclear radius to be r â‰ 0.25-0.29 km, and its colours g? - r? = 0.58 ± 0.05 and r? - i? = 0.23 ± 0.06, typical for an S-class asteroid, as expected for an object in the inner asteroid belt and in the vicinity of the Flora collisional family. We failed to detect any rotational light curve with an amplitude <0.05 mag and a double-peaked rotation period <20 h. The evolution of the tail during the observations was as expected from a dust tail. A detailed Finson-Probstein analysis of deep images acquired with the NTT in early September and with the CFHT in late September indicated that the object was active since at least late January 2013 until the time of the latest observations in 2013 September, with at least two peaks of activity around 2013 June 14 ± 10 d and 2013 July 22 ± 3 d. The changes of activity level and the activity peaks were extremely sharp and short, shorter than the temporal resolution of our observations (?1 d). The dust distribution was similar during these two events, with dust grains covering at least the 1-1000 ?m range. The total mass ejected in grains <1 mm was estimated to be 3.0 × 106 kg and 2.6 × 107 kg around the two activity peaks. Rotational disruption cannot be ruled out as the cause of the dust ejection. We also propose that the components of a contact binary might gently rub and produce the observed emission. Volatile sublimation might also explain what appears as cometary activity over a period of 8 months. However, while main belt comets best explained by ice sublimation are found in the ou
Published: 2014

78. Herschelobservations of gas and dust in comet C/2006 W3 (Christensen) at 5 AU from the Sun

Author: de Val-Borro, M., primary, Bockelée-Morvan, D., additional, Jehin, E., additional, Hartogh, P., additional, Opitom, C., additional, Szutowicz, S., additional, Biver, N., additional, Crovisier, J., additional, Lis, D. C., additional, Rezac, L., additional, de Graauw, Th., additional, Hutsemékers, D., additional, Jarchow, C., additional, Kidger, M., additional, Küppers, M., additional, Lara, L. M., additional, Manfroid, J., additional, Rengel, M., additional, Swinyard, B. M., additional, Teyssier, D., additional, Vandenbussche, B., additional, and Waelkens, C., additional
Published: 2014
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79. A ring system detected around the Centaur (10199) Chariklo

Author: Braga-Ribas, F., primary, Sicardy, B., additional, Ortiz, J. L., additional, Snodgrass, C., additional, Roques, F., additional, Vieira-Martins, R., additional, Camargo, J. I. B., additional, Assafin, M., additional, Duffard, R., additional, Jehin, E., additional, Pollock, J., additional, Leiva, R., additional, Emilio, M., additional, Machado, D. I., additional, Colazo, C., additional, Lellouch, E., additional, Skottfelt, J., additional, Gillon, M., additional, Ligier, N., additional, Maquet, L., additional, Benedetti-Rossi, G., additional, Gomes, A. Ramos, additional, Kervella, P., additional, Monteiro, H., additional, Sfair, R., additional, Moutamid, M. El, additional, Tancredi, G., additional, Spagnotto, J., additional, Maury, A., additional, Morales, N., additional, Gil-Hutton, R., additional, Roland, S., additional, Ceretta, A., additional, Gu, S.-h., additional, Wang, X.-b., additional, Harpsøe, K., additional, Rabus, M., additional, Manfroid, J., additional, Opitom, C., additional, Vanzi, L., additional, Mehret, L., additional, Lorenzini, L., additional, Schneiter, E. M., additional, Melia, R., additional, Lecacheux, J., additional, Colas, F., additional, Vachier, F., additional, Widemann, T., additional, Almenares, L., additional, Sandness, R. G., additional, Char, F., additional, Perez, V., additional, Lemos, P., additional, Martinez, N., additional, Jørgensen, U. G., additional, Dominik, M., additional, Roig, F., additional, Reichart, D. E., additional, LaCluyze, A. P., additional, Haislip, J. B., additional, Ivarsen, K. M., additional, Moore, J. P., additional, Frank, N. R., additional, and Lambas, D. G., additional
Published: 2014
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80. A MONITORING CAMPAIGN FOR LUHMAN 16AB. I. DETECTION OF RESOLVED NEAR-INFRARED SPECTROSCOPIC VARIABILITY

Author: Burgasser, Adam J., primary, Gillon, Michaël, additional, Faherty, Jacqueline K., additional, Radigan, Jacqueline, additional, Triaud, Amaury H. M. J., additional, Plavchan, Peter, additional, Street, Rachel, additional, Jehin, E., additional, Delrez, L., additional, and Opitom, C., additional
Published: 2014
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81. Continued activity in P/2013 P5 PANSTARRS

Author: Hainaut, O. R., primary, Boehnhardt, H., additional, Snodgrass, C., additional, Meech, K. J., additional, Deller, J., additional, Gillon, M., additional, Jehin, E., additional, Kuehrt, E., additional, Lowry, S. C., additional, Manfroid, J., additional, Micheli, M., additional, Mottola, S., additional, Opitom, C., additional, Vincent, J.-B., additional, and Wainscoat, R., additional
Published: 2014
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82. Fast-evolving weather for the coolest of our two new substellar neighbours

Author: Gillon, M., primary, Triaud, A. H. M. J., additional, Jehin, E., additional, Delrez, L., additional, Opitom, C., additional, Magain, P., additional, Lendl, M., additional, and Queloz, D., additional
Published: 2013
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83. Distant activity of comet C/2006 W3 (Christensen) as observed with Herschel

Author: Miguel de Val-Borro, Bockelée-Morvan, D., Jehin, E., Hartogh, P., Opitom, C., Szutowicz, S., Biver, N., Crovisier, J., Lis, D., Rezac, L., Graauw, T., Hutsemékers, D., Jarchow, C., Kidger, M. R., Küppers, M., Lara, L. M., Manfroid, J., Rengel, M., Swinyard, B. M., Teyssier, D., Vandenbussche, B., and Waelkens, C.

84. Exocomets from a solar system perspective

Author: Strøm, PA, Bodewits, D, Knight, MM, Kiefer, F, Jones, GH, Kral, Q, Matrà, L, Bodman, E, Capria, MT, Cleeves, I, Fitzsimmons, A, Haghighipour, N, Harrison, JHD, Iglesias, D, Kama, M, Linnartz, H, Majumdar, L, De Mooij, EJW, Milam, SN, Opitom, C, Rebollido, I, Rogers, LK, Snodgrass, C, Sousa-Silva, C, Xu, S, Lin, ZY, and Zieba, S
Subjects: 13. Climate action, 5101 Astronomical Sciences, Physics::Space Physics, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, 5109 Space Sciences, 51 Physical Sciences, Astrophysics::Galaxy Astrophysics
Abstract: Exocomets are small bodies releasing gas and dust which orbit stars other than the Sun. Their existence was first inferred from the detection of variable absorption features in stellar spectra in the late 1980s using spectroscopy. More recently, they have been detected through photometric transits from space, and through far-IR/mm gas emission within debris disks. As (exo)comets are considered to contain the most pristine material accessible in stellar systems, they hold the potential to give us information about early stage formation and evolution conditions of extra solar systems. In the solar system, comets carry the physical and chemical memory of the protoplanetary disk environment where they formed, providing relevant information on processes in the primordial solar nebula. The aim of this paper is to compare essential compositional properties between solar system comets and exocomets to allow for the development of new observational methods and techniques. The paper aims to highlight commonalities and to discuss differences which may aid the communication between the involved research communities and perhaps also avoid misconceptions. The compositional properties of solar system comets and exocomets are summarized before providing an observational comparison between them. Exocomets likely vary in their composition depending on their formation environment like solar system comets do, and since exocomets are not resolved spatially, they pose a challenge when comparing them to high fidelity observations of solar system comets. Observations of gas around main sequence stars, spectroscopic observations of “polluted” white dwarf atmospheres and spectroscopic observations of transiting exocomets suggest that exocomets may show compositional similarities with solar system comets. The recent interstellar visitor 2I/Borisov showed gas, dust and nuclear properties similar to that of solar system comets. This raises the tantalising prospect that observations of interstellar comets may help bridge the fields of exocomet and solar system comets.

85. A ring system detected around the Centaur (10199) Chariklo

Author: Lellouch, E., Dominik, M., Maquet, L., Char, F., Wang, X.-b., Reichart, D. E., Mehret, L., Martinez, N., Schneiter, E. M., Morales, N., Moore, J. P., Perez, V., Ligier, N., LaCluyze, A. P., Duffard, R., Ramos Gomes, A., Gil-Hutton, R., Roig, F., Colas, F., Snodgrass, C., Almenares, L., Vieira-Martins, R., Lecacheux, J., Spagnotto, J., Roques, F., Gillon, M., Manfroid, J., Sandness, R. G., Assafin, M., Vanzi, L., Lemos, P., Opitom, C., Skottfelt, J., Widemann, T., El Moutamid, M., Emilio, M., Harpsøe, K., Lambas, D. G., Haislip, J. B., Sfair, R., Jørgensen, U. G., Rabus, M., Monteiro, H., Braga-Ribas, F., Frank, N. R., Ceretta, A., Lorenzini, L., Camargo, J. I. B., Maury, A., Colazo, C., Ortiz, J. L., Vachier, F., Jehin, E., Benedetti-Rossi, G., Machado, D. I., Roland, S., Sicardy, B., Melia, R., Gu, S.-h., Pollock, J., Tancredi, G., Leiva, R., Kervella, P., and Ivarsen, K. M.
Subjects: Astrophysics::Earth and Planetary Astrophysics, 7. Clean energy
Abstract: Until now, rings have been detected in the Solar System exclusively around the four giant planets. Here we report the discovery of the rst minor-body ring system around the Centaur object (10199) Chariklo, a body with equivalent radius 124±9 km. A multi-chord stellar occultation revealed the presence of two dense rings around Chariklo, with widths of about 7 km and 3 km, optical depths 0.4 and 0.06, and orbital radii 391 and 405 km, respectively. The present orientation of the ring is consistent with an edge-on geometry in 2008, thus providing a simple explanation for the dimming of Chariklo's system between 1997 and 2008, and for the gradual disappearance of ice and other absorption features in its spectrum over the same period. This implies that the rings are partially composed of water ice. These rings may be the remnants of a debris disk, which were possibly con ned by embedded kilometre-sized satellites.

86. PLUTO’s ATMOSPHERE FROM STELLAR OCCULTATIONS IN 2012 AND 2013

Author: Leiva, R., Vieira-Martins, R., Gomes-Júnior, A. R., Girard, J. H., Snodgrass, C., Assafin, M., Pollock, J., Jehin, E., Decock, A., Opitom, C., Hau, G. K.T., Reichart, D. E., Camargo, J. I.B., Lopez-Sisterna, C., Colas, F., Dias-Oliveira, A., Ortiz, J. L., Skottfelt, J., Mancini, L., Doressoundiram, A., Vanzi, L., Manfroid, J., Braga-Ribas, F., Roques, F., Ivarsen, K. M., Gillon, M., Haislip, J. B., Maury, A., Fabrega Polleri, J., Gil-Hutton, R., Nagy, L., Soulier, J. F., Emilio, M., Thirouin, A., Lecacheux, J., Sicardy, B., Morales, N., Dominik, M., Dumas, C., Meza, E., Lellouch, E., Jørgensen, U., Benedetti-Rossi, G., Widemann, T., Lacluyze, A. P., and Ivanov, V. D.
Subjects: 13. Climate action
Abstract: We analyze two multi-chord stellar occultations by Pluto observed on July 18th, 2012 and May 4th, 2013, and monitored respectively from five and six sites. They provide a total of fifteen light-curves, twelve of them being used for a simultaneous fit that uses a unique temperature profile, assuming a clear (no-haze) and pure N_2 atmosphere, but allowing for a possible pressure variation between the two dates. We find a solution that fits satisfactorily (i.e. within the noise level) all the twelve light-curves, providing atmospheric constraints between ~1,190 km (pressure ~ 11 \mubar) and ~ 1,450 km (pressure ~0.1 \mubar) from Pluto's center. Our main results are: (1) the best-fitting temperature profile shows a stratosphere with strong positive gradient between 1,190 km (at 36 K, 11 \mubar) and r = 1,215 km (6.0 \mubar), where a temperature maximum of 110 K is reached; above it is a mesosphere with negative thermal gradient of -0.2 K/km up to ~ 1,390 km (0.25 \mubar), where, the mesosphere connects itself to a more isothermal upper branch around 81 K; (2) the pressure shows a small (6

87. The dust environment of comet 67P/Churyumov-Gerasimenko from Rosetta OSIRIS and VLT observations in the 4.5 to 2.9 AU heliocentric distance range inbound

Author: Agarwal, J., Besse, S., Guettler, C., Naletto, G., Tozzi, G. P., Snodgrass, C., Marzari, F., Fulle, M., Gutierrez-Marques, P., Bertaux, J. L., Kramm, J. R., Jehin, E., A'Hearn, M. F., Keller, H. U., Barbieri, C., Gutierrez, P. J., Vincent, J. B., Bertini, I., Hainaut, O., Kuehrt, E., Lara, L. M., Debei, S., Sierks, H., Kovacs, G., De Cecco, M., Ferri, F., Da Deppo, V., Lopez-Moreno, J. J., Ip, W. H., Mottola, S., Pajola, M., Rickman, H., Faggi, S., Fornasier, S., Della Corte, V., Tubiana, C., Jorda, L., Thomas, Nicolas, Knollenberg, J., Moreno, F., Groussin, O., Bodewits, D., Hviid, S. F., Rodrigo, R., Cremonese, G., Oklay, N., Kueppers, M., Koschny, D., Opitom, C., Fitzsimmons, A., Barucci, M. A., Lamy, P. L., Davidsson, B., and Lazzarin, M.
Subjects: 13. Climate action, 530 Physics, 520 Astronomy
Abstract: Context. The ESA Rosetta spacecraft, currently orbiting around cornet 67P/Churyumov-Gerasimenko, has already provided in situ measurements of the dust grain properties from several instruments, particularly OSIRIS and GIADA. We propose adding value to those measurements by combining them with ground-based observations of the dust tail to monitor the overall, time-dependent dust-production rate and size distribution. Aims. To constrain the dust grain properties, we take Rosetta OSIRIS and GIADA results into account, and combine OSIRIS data during the approach phase (from late April to early June 2014) with a large data set of ground-based images that were acquired with the ESO Very Large Telescope (VLT) from February to November 2014. Methods. A Monte Carlo dust tail code, which has already been used to characterise the dust environments of several comets and active asteroids, has been applied to retrieve the dust parameters. Key properties of the grains (density, velocity, and size distribution) were obtained from. Rosetta observations: these parameters were used as input of the code to considerably reduce the number of free parameters. In this way, the overall dust mass-loss rate and its dependence on the heliocentric distance could be obtained accurately. Results. The dust parameters derived from the inner coma measurements by OSIRIS and GIADA and from distant imaging using VLT data are consistent, except for the power index of the size-distribution function, which is alpha = -3, instead of alpha = -2, for grains smaller than 1 mm. This is possibly linked to the presence of fluffy aggregates in the coma. The onset of cometary activity occurs at approximately 4.3 AU, with a dust production rate of 0.5 kg/s, increasing up to 15 kg/s at 2.9 AU. This implies a dust-to-gas mass ratio varying between 3.8 and 6.5 for the best-fit model when combined with water-production rates from the MIRO experiment.

88. The 2016 Feb 19 Outburst of Comet 67P/CG: An ESA Rosetta Multi-Instrument Study

Author: Grün, E., Agarwal, J., Altobelli, N., Altwegg, K., Bentley, M. S., Biver, N., Della Corte, V., Edberg, N., Feldman, P. D., Galand, M., Geiger, B., Götz, C., Grieger, B., Güttler, C., Henri, P., Hofstadter, M., Horanyi, M., Jehin, E., Krüger, H., Lee, S., Mannel, T., Morales, E., Mousis, O., Müller, M., Opitom, C., Rotundi, A., Schmied, R., Schmidt, F., Sierks, H., Snodgrass, Colin, Soja, R. H., Sommer, M., Srama, R., Tzou, C.-Y., Vincent, J.-B., Yanamandra-Fisher, P., A’Hearn, M. F., Erikson, A. I., Barbieri, C., Barucci, M. A., Bertaux, J.-L., Bertini, I., Burch, J., Colangeli, L., Cremonese, G., Da Deppo, V., Davidsson, B., Debei, S., De Cecco, M., Deller, J., Feaga, L. M., Ferrari, M., Fornasier, S., Fulle, M., Gicquel, A., Gillon, M., Green, S. F., Groussin, O., Gutiérrez, P. J., Hofmann, M., Hviid, S. F., Ip, W.-H., Ivanovski, S., Jorda, L., Keller, H. U., Knight, M. M., Knollenberg, J., Koschny, D., Kramm, J.-R., Kührt, E., Küppers, M., Lamy, P. L., Lara, L. M., Lazzarin, M., Lòpez-Moreno, J. J., Manfroid, J., Mazzotta Epifani, E., Marzari, F., Naletto, G., Oklay, N., Palumbo, P., Parker, J. Wm., Rickman, H., Rodrigo, R., Rodrìguez, J., Schindhelm, E., Shi, X., Sordini, R., Steffl, A. J., Stern, S. A., Thomas, N., Tubiana, C., Weaver, H. A., Weissman, P., Zakharov, V. V., Taylor, M. G. G. T., Grün, E., Agarwal, J., Altobelli, N., Altwegg, K., Bentley, M. S., Biver, N., Della Corte, V., Edberg, N., Feldman, P. D., Galand, M., Geiger, B., Götz, C., Grieger, B., Güttler, C., Henri, P., Hofstadter, M., Horanyi, M., Jehin, E., Krüger, H., Lee, S., Mannel, T., Morales, E., Mousis, O., Müller, M., Opitom, C., Rotundi, A., Schmied, R., Schmidt, F., Sierks, H., Snodgrass, Colin, Soja, R. H., Sommer, M., Srama, R., Tzou, C.-Y., Vincent, J.-B., Yanamandra-Fisher, P., A’Hearn, M. F., Erikson, A. I., Barbieri, C., Barucci, M. A., Bertaux, J.-L., Bertini, I., Burch, J., Colangeli, L., Cremonese, G., Da Deppo, V., Davidsson, B., Debei, S., De Cecco, M., Deller, J., Feaga, L. M., Ferrari, M., Fornasier, S., Fulle, M., Gicquel, A., Gillon, M., Green, S. F., Groussin, O., Gutiérrez, P. J., Hofmann, M., Hviid, S. F., Ip, W.-H., Ivanovski, S., Jorda, L., Keller, H. U., Knight, M. M., Knollenberg, J., Koschny, D., Kramm, J.-R., Kührt, E., Küppers, M., Lamy, P. L., Lara, L. M., Lazzarin, M., Lòpez-Moreno, J. J., Manfroid, J., Mazzotta Epifani, E., Marzari, F., Naletto, G., Oklay, N., Palumbo, P., Parker, J. Wm., Rickman, H., Rodrigo, R., Rodrìguez, J., Schindhelm, E., Shi, X., Sordini, R., Steffl, A. J., Stern, S. A., Thomas, N., Tubiana, C., Weaver, H. A., Weissman, P., Zakharov, V. V., and Taylor, M. G. G. T.
Abstract: On 19 Feb. 2016 nine Rosetta instruments serendipitously observed an outburst of gas and dust from the nucleus of comet 67P/Churyumov-Gerasimenko. Among these instruments were cameras and spectrometers ranging from UV over visible to microwave wavelengths, in-situ gas, dust and plasma instruments, and one dust collector. At 9:40 a dust cloud developed at the edge of an image in the shadowed region of the nucleus. Over the next two hours the instruments recorded a signature of the outburst that significantly exceeded the background. The enhancement ranged from 50% of the neutral gas density at Rosetta to factors >100 of the brightness of the coma near the nucleus. Dust related phenomena (dust counts or brightness due to illuminated dust) showed the strongest enhancements (factors >10). However, even the electron density at Rosetta increased by a factor 3 and consequently the spacecraft potential changed from ∼−16 V to −20 V during the outburst. A clear sequence of events was observed at the distance of Rosetta (34 km from the nucleus): within 15 minutes the Star Tracker camera detected fast particles (∼25 m s−1) while 100 μm radius particles were detected by the GIADA dust instrument ∼1 hour later at a speed of ~6 m s−1. The slowest were individual mm to cm sized grains observed by the OSIRIS cameras. Although the outburst originated just outside the FOV of the instruments, the source region and the magnitude of the outburst could be determined.

89. The 67P/Churyumov–Gerasimenko observation campaign in support of the Rosetta mission

Author: Snodgrass, C., A'Hearn, M. F., Aceituno, F., Afanasiev, V., Bagnulo, S., Bauer, J., Bergond, G., Besse, S., Biver, N., Bodewits, D., Boehnhardt, H., Bonev, B. P., Borisov, G., Carry, B., Casanova, V., Cochran, A., Conn, B. C., Davidsson, B., Davies, J. K., de León, J., de Mooij, E., de Val-Borro, M., Delacruz, M., DiSanti, M. A., Drew, J. E., Duffard, R., Edberg, N. J. T., Faggi, S., Feaga, L., Fitzsimmons, A., Fujiwara, H., Gibb, E. L., Gillon, M., Green, S. F., Guijarro, A., Guilbert-Lepoutre, A., Gutiérrez, P. J., Hadamcik, E., Hainaut, O., Haque, S., Hedrosa, R., Hines, D., Hopp, U., Hoyo, F., Hutsemékers, D., Hyland, M., Ivanova, O., Jehin, E., Jones, G. H., Keane, J. V., Kelley, M. S. P., Kiselev, N., Kleyna, J., Kluge, M., Knight, M. M., Kokotanekova, R., Koschny, D., Kramer, E. A., López-Moreno, J. J., Lacerda, P., Lara, L. M., Lasue, J., Lehto, H. J., Levasseur-Regourd, A. C., Licandro, J., Lin, Z. Y., Lister, T., Lowry, S. C., Mainzer, A., Manfroid, J., Marchant, J., McKay, A. J., McNeill, A., Meech, K. J., Micheli, M., Mohammed, I., Monguió, M., Moreno, F., Muñoz, O., Mumma, M. J., Nikolov, P., Opitom, C., Ortiz, J. L., Paganini, L., Pajuelo, M., Pozuelos, F. J., Protopapa, S., Pursimo, T., Rajkumar, B., Ramanjooloo, Y., Ramos, E., Ries, C., Riffeser, A., Rosenbush, V., Rousselot, P., Ryan, E. L., Santos-Sanz, P., Schleicher, D. G., Schmidt, M., Schulz, R., Sen, A. K., Somero, A., Sota, A., Stinson, A., Sunshine, J. M., Thompson, A., Tozzi, G. P., Tubiana, C., Villanueva, G. L., Wang, X., Wooden, D. H., Yagi, M., Yang, B., Zaprudin, B., Zegmott, T. J., Snodgrass, C., A'Hearn, M. F., Aceituno, F., Afanasiev, V., Bagnulo, S., Bauer, J., Bergond, G., Besse, S., Biver, N., Bodewits, D., Boehnhardt, H., Bonev, B. P., Borisov, G., Carry, B., Casanova, V., Cochran, A., Conn, B. C., Davidsson, B., Davies, J. K., de León, J., de Mooij, E., de Val-Borro, M., Delacruz, M., DiSanti, M. A., Drew, J. E., Duffard, R., Edberg, N. J. T., Faggi, S., Feaga, L., Fitzsimmons, A., Fujiwara, H., Gibb, E. L., Gillon, M., Green, S. F., Guijarro, A., Guilbert-Lepoutre, A., Gutiérrez, P. J., Hadamcik, E., Hainaut, O., Haque, S., Hedrosa, R., Hines, D., Hopp, U., Hoyo, F., Hutsemékers, D., Hyland, M., Ivanova, O., Jehin, E., Jones, G. H., Keane, J. V., Kelley, M. S. P., Kiselev, N., Kleyna, J., Kluge, M., Knight, M. M., Kokotanekova, R., Koschny, D., Kramer, E. A., López-Moreno, J. J., Lacerda, P., Lara, L. M., Lasue, J., Lehto, H. J., Levasseur-Regourd, A. C., Licandro, J., Lin, Z. Y., Lister, T., Lowry, S. C., Mainzer, A., Manfroid, J., Marchant, J., McKay, A. J., McNeill, A., Meech, K. J., Micheli, M., Mohammed, I., Monguió, M., Moreno, F., Muñoz, O., Mumma, M. J., Nikolov, P., Opitom, C., Ortiz, J. L., Paganini, L., Pajuelo, M., Pozuelos, F. J., Protopapa, S., Pursimo, T., Rajkumar, B., Ramanjooloo, Y., Ramos, E., Ries, C., Riffeser, A., Rosenbush, V., Rousselot, P., Ryan, E. L., Santos-Sanz, P., Schleicher, D. G., Schmidt, M., Schulz, R., Sen, A. K., Somero, A., Sota, A., Stinson, A., Sunshine, J. M., Thompson, A., Tozzi, G. P., Tubiana, C., Villanueva, G. L., Wang, X., Wooden, D. H., Yagi, M., Yang, B., Zaprudin, B., and Zegmott, T. J.
Abstract: We present a summary of the campaign of remote observations that supported the European Space Agency's Rosetta mission. Telescopes across the globe (and in space) followed comet 67P/Churyumov–Gerasimenko from before Rosetta's arrival until nearly the end of the mission in September 2016. These provided essential data for mission planning, large-scale context information for the coma and tails beyond the spacecraft and a way to directly compare 67P with other comets. The observations revealed 67P to be a relatively ‘well-behaved’ comet, typical of Jupiter family comets and with activity patterns that repeat from orbit to orbit. Comparison between this large collection of telescopic observations and the in situ results from Rosetta will allow us to better understand comet coma chemistry and structure. This work is just beginning as the mission ends—in this paper, we present a summary of the ground-based observations and early results, and point to many questions that will be addressed in future studies.

90. Ground-based monitoring of comet 67P/Churyumov-Gerasimenko gas activity throughout the Rosetta mission

Author: Opitom, C., Snodgrass, C., Fitzsimmons, A., Jehin, E., Manfroid, J., Tozzi, G. P., Faggi, S., Gillon, M., Opitom, C., Snodgrass, C., Fitzsimmons, A., Jehin, E., Manfroid, J., Tozzi, G. P., Faggi, S., and Gillon, M.
Abstract: Simultaneously to the ESA Rosetta mission, a world-wide ground-based campaign provided measurements of the large scale activity of comet 67P/Churyumov-Gerasimenko through measurement of optically active gas species and imaging of the overall dust coma. We present more than two years of observations performed with the FORS2 low resolution spectrograph at the VLT, TRAPPIST, and ACAM at the WHT. We focus on the evolution of the CN production, as a tracer of the comet activity. We find that it is asymmetric with respect to perihelion and different from that of the dust. The CN emission is detected for the first time at 1.34 au pre-perihelion and production rates then increase steeply to peak about two weeks after perihelion at (1.00±0.10) ×1025 molecules s−1, while the post-perihelion decrease is more shallow. The evolution of the comet activity is strongly influenced by seasonal effects, with enhanced CN production when the Southern hemisphere is illuminated.

91. Morphology and spectral properties of the DART impact ejecta with VLT/MUSE

Author: Opitom, C., Murphy, B., Snodgrass, C., Bagnulo, S., Green, S. F., Knight, M. M., de Léon, J., Li, J.-Y., Gardener, D., Opitom, C., Murphy, B., Snodgrass, C., Bagnulo, S., Green, S. F., Knight, M. M., de Léon, J., Li, J.-Y., and Gardener, D.
Abstract: Context. On September 26, 2022, the NASA DART mission impacted the asteroid Dimorphos, the smaller component of the Didymos binary asteroid system. This provided a unique opportunity to observe, in real time, the evolution of the ejecta cloud produced by the impact and the formation of a tail. Aims. We present observations performed with the MUSE instrument at the Very Large Telescope to characterise the morphology, spectral properties, and evolution of the ejecta. The Didymos system was observed with MUSE on 11 nights from just before impact to almost one month post-impact, using both wide-field observations without adaptive optics and narrow-field observations with adaptive optics. Methods. We produced white light images that were used to study the morphology of the ejecta at different spatial scales. The spectral information was used to search for gas emission from either exposed ice or propellant, and to study the spatial and temporal variation of the ejecta dust reflectance through reflectance maps. Results. We searched for, but did not detect, emission from [OI], Xe, NH2, and H2O+ in a 1′×1′ field of view in our observations starting almost 4h after impact. We detected a number of morphological features, including a short-lived ejecta cloud visible on September 27 towards the east, spirals, clumps, and a tail that started forming only a few hours after impact. The analysis of the reflectance maps showed that the initial ejecta was bluer than the system before impact, while the tail and spirals were redder than the initial ejecta, consistent with them being made of larger particles. Over the few weeks following impact, the tail became redder. No significant colour differences could be seen between the clumps and the initial ejecta.

92. Ground-based monitoring of comet 67P/Churyumov-Gerasimenko gas activity throughout the Rosetta mission

Author: Opitom, C., Snodgrass, C., Fitzsimmons, A., Jehin, E., Manfroid, J., Tozzi, G. P., Faggi, S., Gillon, M., Opitom, C., Snodgrass, C., Fitzsimmons, A., Jehin, E., Manfroid, J., Tozzi, G. P., Faggi, S., and Gillon, M.
Abstract: Simultaneously to the ESA Rosetta mission, a world-wide ground-based campaign provided measurements of the large scale activity of comet 67P/Churyumov-Gerasimenko through measurement of optically active gas species and imaging of the overall dust coma. We present more than two years of observations performed with the FORS2 low resolution spectrograph at the VLT, TRAPPIST, and ACAM at the WHT. We focus on the evolution of the CN production, as a tracer of the comet activity. We find that it is asymmetric with respect to perihelion and different from that of the dust. The CN emission is detected for the first time at 1.34 au pre-perihelion and production rates then increase steeply to peak about two weeks after perihelion at (1.00±0.10) ×1025 molecules s−1, while the post-perihelion decrease is more shallow. The evolution of the comet activity is strongly influenced by seasonal effects, with enhanced CN production when the Southern hemisphere is illuminated.
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93. The 67P/Churyumov–Gerasimenko observation campaign in support of the Rosetta mission

Author: Snodgrass, C., A'Hearn, M. F., Aceituno, F., Afanasiev, V., Bagnulo, S., Bauer, J., Bergond, G., Besse, S., Biver, N., Bodewits, D., Boehnhardt, H., Bonev, B. P., Borisov, G., Carry, B., Casanova, V., Cochran, A., Conn, B. C., Davidsson, B., Davies, J. K., de León, J., de Mooij, E., de Val-Borro, M., Delacruz, M., DiSanti, M. A., Drew, J. E., Duffard, R., Edberg, N. J. T., Faggi, S., Feaga, L., Fitzsimmons, A., Fujiwara, H., Gibb, E. L., Gillon, M., Green, S. F., Guijarro, A., Guilbert-Lepoutre, A., Gutiérrez, P. J., Hadamcik, E., Hainaut, O., Haque, S., Hedrosa, R., Hines, D., Hopp, U., Hoyo, F., Hutsemékers, D., Hyland, M., Ivanova, O., Jehin, E., Jones, G. H., Keane, J. V., Kelley, M. S. P., Kiselev, N., Kleyna, J., Kluge, M., Knight, M. M., Kokotanekova, R., Koschny, D., Kramer, E. A., López-Moreno, J. J., Lacerda, P., Lara, L. M., Lasue, J., Lehto, H. J., Levasseur-Regourd, A. C., Licandro, J., Lin, Z. Y., Lister, T., Lowry, S. C., Mainzer, A., Manfroid, J., Marchant, J., McKay, A. J., McNeill, A., Meech, K. J., Micheli, M., Mohammed, I., Monguió, M., Moreno, F., Muñoz, O., Mumma, M. J., Nikolov, P., Opitom, C., Ortiz, J. L., Paganini, L., Pajuelo, M., Pozuelos, F. J., Protopapa, S., Pursimo, T., Rajkumar, B., Ramanjooloo, Y., Ramos, E., Ries, C., Riffeser, A., Rosenbush, V., Rousselot, P., Ryan, E. L., Santos-Sanz, P., Schleicher, D. G., Schmidt, M., Schulz, R., Sen, A. K., Somero, A., Sota, A., Stinson, A., Sunshine, J. M., Thompson, A., Tozzi, G. P., Tubiana, C., Villanueva, G. L., Wang, X., Wooden, D. H., Yagi, M., Yang, B., Zaprudin, B., Zegmott, T. J., Snodgrass, C., A'Hearn, M. F., Aceituno, F., Afanasiev, V., Bagnulo, S., Bauer, J., Bergond, G., Besse, S., Biver, N., Bodewits, D., Boehnhardt, H., Bonev, B. P., Borisov, G., Carry, B., Casanova, V., Cochran, A., Conn, B. C., Davidsson, B., Davies, J. K., de León, J., de Mooij, E., de Val-Borro, M., Delacruz, M., DiSanti, M. A., Drew, J. E., Duffard, R., Edberg, N. J. T., Faggi, S., Feaga, L., Fitzsimmons, A., Fujiwara, H., Gibb, E. L., Gillon, M., Green, S. F., Guijarro, A., Guilbert-Lepoutre, A., Gutiérrez, P. J., Hadamcik, E., Hainaut, O., Haque, S., Hedrosa, R., Hines, D., Hopp, U., Hoyo, F., Hutsemékers, D., Hyland, M., Ivanova, O., Jehin, E., Jones, G. H., Keane, J. V., Kelley, M. S. P., Kiselev, N., Kleyna, J., Kluge, M., Knight, M. M., Kokotanekova, R., Koschny, D., Kramer, E. A., López-Moreno, J. J., Lacerda, P., Lara, L. M., Lasue, J., Lehto, H. J., Levasseur-Regourd, A. C., Licandro, J., Lin, Z. Y., Lister, T., Lowry, S. C., Mainzer, A., Manfroid, J., Marchant, J., McKay, A. J., McNeill, A., Meech, K. J., Micheli, M., Mohammed, I., Monguió, M., Moreno, F., Muñoz, O., Mumma, M. J., Nikolov, P., Opitom, C., Ortiz, J. L., Paganini, L., Pajuelo, M., Pozuelos, F. J., Protopapa, S., Pursimo, T., Rajkumar, B., Ramanjooloo, Y., Ramos, E., Ries, C., Riffeser, A., Rosenbush, V., Rousselot, P., Ryan, E. L., Santos-Sanz, P., Schleicher, D. G., Schmidt, M., Schulz, R., Sen, A. K., Somero, A., Sota, A., Stinson, A., Sunshine, J. M., Thompson, A., Tozzi, G. P., Tubiana, C., Villanueva, G. L., Wang, X., Wooden, D. H., Yagi, M., Yang, B., Zaprudin, B., and Zegmott, T. J.
Abstract: We present a summary of the campaign of remote observations that supported the European Space Agency's Rosetta mission. Telescopes across the globe (and in space) followed comet 67P/Churyumov–Gerasimenko from before Rosetta's arrival until nearly the end of the mission in September 2016. These provided essential data for mission planning, large-scale context information for the coma and tails beyond the spacecraft and a way to directly compare 67P with other comets. The observations revealed 67P to be a relatively ‘well-behaved’ comet, typical of Jupiter family comets and with activity patterns that repeat from orbit to orbit. Comparison between this large collection of telescopic observations and the in situ results from Rosetta will allow us to better understand comet coma chemistry and structure. This work is just beginning as the mission ends—in this paper, we present a summary of the ground-based observations and early results, and point to many questions that will be addressed in future studies.
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94. Exocomets from a solar system perspective

Author: Eva H. L. Bodman, Maria Teresa Capria, I. Rebollido, Liton Majumdar, Alan Fitzsimmons, Siyi Xu, Ernst J. W. de Mooij, Harold Linnartz, Nader Haghighipour, John H. D. Harrison, P. A. Strøm, Luca Matrà, D. Iglesias, Mihkel Kama, Dennis Bodewits, Matthew M. Knight, Colin Snodgrass, Sebastian Zieba, Cyrielle Opitom, Stefanie N. Milam, Laura K. Rogers, Ilsedore Cleeves, Flavien Kiefer, Quentin Kral, Clara Sousa-Silva, Geraint H. Jones, Zhong-Yi Lin, Strøm, PA [0000-0002-7823-1090], Bodewits, D [0000-0002-2668-7248], Knight, MM [0000-0003-2781-6897], Kiefer, F [0000-0001-9129-4929], Jones, GH [0000-0002-5859-1136], Kral, Q [0000-0001-6527-4684], Matrà, L [0000-0003-4705-3188], Bodman, E [0000-0002-4133-5216], Capria, MT [0000-0002-9814-9588], Cleeves, I [0000-0003-2076-8001], Fitzsimmons, A [0000-0003-0250-9911], Haghighipour, N [0000-0002-5234-6375], Harrison, JHD [0000-0002-9971-4956], Iglesias, D [0000-0002-0756-9836], Kama, M [0000-0003-0065-7267], Linnartz, H [0000-0002-8322-3538], Majumdar, L [0000-0001-7031-8039], de Mooij, EJW [0000-0001-6391-9266], Milam, SN [0000-0001-7694-4129], Opitom, C [0000-0002-9298-7484], Rebollido, I [0000-0002-4388-6417], Rogers, LK [0000-0002-3553-9474], Snodgrass, C [0000-0001-9328-2905], Sousa-Silva, C [0000-0002-7853-6871], Xu, S [0000-0002-8808-4282], Lin, ZY [0000-0003-3827-8991], Zieba, S [0000-0003-0562-6750], Apollo - University of Cambridge Repository, Institut d'Astrophysique de Paris (IAP), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)
Subjects: Solar System, astro-ph.SR, 010504 meteorology & atmospheric sciences, Main-belt comets, FOS: Physical sciences, 5109 Space Sciences, Protoplanetary disk, 01 natural sciences, Astronomical spectroscopy, Astrobiology, Kuiper belt, Photometry, Exocomets, 0103 physical sciences, Comets, Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, QC, Solar and Stellar Astrophysics (astro-ph.SR), Spectroscopy, Astrophysics::Galaxy Astrophysics, QB, 0105 earth and related environmental sciences, Physics, Earth and Planetary Astrophysics (astro-ph.EP), White dwarf, Small solar system bodies, Astronomy and Astrophysics, Stars, Astrophysics - Solar and Stellar Astrophysics, 13. Climate action, 5101 Astronomical Sciences, Space and Planetary Science, Physics::Space Physics, astro-ph.EP, Astrophysics::Earth and Planetary Astrophysics, Formation and evolution of the Solar System, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 51 Physical Sciences, Main sequence, Astrophysics - Earth and Planetary Astrophysics, Extrasolar Small Bodies, Exocomet
Abstract: Exocomets are small bodies releasing gas and dust which orbit stars other than the Sun. Their existence was first inferred from the detection of variable absorption features in stellar spectra in the late 1980s using spectroscopy. More recently, they have been detected through photometric transits from space, and through far-IR/mm gas emission within debris disks. As (exo)comets are considered to contain the most pristine material accessible in stellar systems, they hold the potential to give us information about early stage formation and evolution conditions of extra Solar Systems. In the Solar System, comets carry the physical and chemical memory of the protoplanetary disk environment where they formed, providing relevant information on processes in the primordial solar nebula. The aim of this paper is to compare essential compositional properties between Solar System comets and exocomets. The paper aims to highlight commonalities and to discuss differences which may aid the communication between the involved research communities and perhaps also avoid misconceptions. Exocomets likely vary in their composition depending on their formation environment like Solar System comets do, and since exocomets are not resolved spatially, they pose a challenge when comparing them to high fidelity observations of Solar System comets. Observations of gas around main sequence stars, spectroscopic observations of "polluted" white dwarf atmospheres and spectroscopic observations of transiting exocomets suggest that exocomets may show compositional similarities with Solar System comets. The recent interstellar visitor 2I/Borisov showed gas, dust and nuclear properties similar to that of Solar System comets. This raises the tantalising prospect that observations of interstellar comets may help bridge the fields of exocomet and Solar System comets., Comment: 25 pages, 3 figures. To be published in PASP. This paper is the product of a workshop at the Lorentz Centre in Leiden, the Netherlands
Published: 2020
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95. The Comet Interceptor Mission.

Author: Jones GH, Snodgrass C, Tubiana C, Küppers M, Kawakita H, Lara LM, Agarwal J, André N, Attree N, Auster U, Bagnulo S, Bannister M, Beth A, Bowles N, Coates A, Colangeli L, Corral van Damme C, Da Deppo V, De Keyser J, Della Corte V, Edberg N, El-Maarry MR, Faggi S, Fulle M, Funase R, Galand M, Goetz C, Groussin O, Guilbert-Lepoutre A, Henri P, Kasahara S, Kereszturi A, Kidger M, Knight M, Kokotanekova R, Kolmasova I, Kossacki K, Kührt E, Kwon Y, La Forgia F, Levasseur-Regourd AC, Lippi M, Longobardo A, Marschall R, Morawski M, Muñoz O, Näsilä A, Nilsson H, Opitom C, Pajusalu M, Pommerol A, Prech L, Rando N, Ratti F, Rothkaehl H, Rotundi A, Rubin M, Sakatani N, Sánchez JP, Simon Wedlund C, Stankov A, Thomas N, Toth I, Villanueva G, Vincent JB, Volwerk M, Wurz P, Wielders A, Yoshioka K, Aleksiejuk K, Alvarez F, Amoros C, Aslam S, Atamaniuk B, Baran J, Barciński T, Beck T, Behnke T, Berglund M, Bertini I, Bieda M, Binczyk P, Busch MD, Cacovean A, Capria MT, Carr C, Castro Marín JM, Ceriotti M, Chioetto P, Chuchra-Konrad A, Cocola L, Colin F, Crews C, Cripps V, Cupido E, Dassatti A, Davidsson BJR, De Roche T, Deca J, Del Togno S, Dhooghe F, Donaldson Hanna K, Eriksson A, Fedorov A, Fernández-Valenzuela E, Ferretti S, Floriot J, Frassetto F, Fredriksson J, Garnier P, Gaweł D, Génot V, Gerber T, Glassmeier KH, Granvik M, Grison B, Gunell H, Hachemi T, Hagen C, Hajra R, Harada Y, Hasiba J, Haslebacher N, Herranz De La Revilla ML, Hestroffer D, Hewagama T, Holt C, Hviid S, Iakubivskyi I, Inno L, Irwin P, Ivanovski S, Jansky J, Jernej I, Jeszenszky H, Jimenéz J, Jorda L, Kama M, Kameda S, Kelley MSP, Klepacki K, Kohout T, Kojima H, Kowalski T, Kuwabara M, Ladno M, Laky G, Lammer H, Lan R, Lavraud B, Lazzarin M, Le Duff O, Lee QM, Lesniak C, Lewis Z, Lin ZY, Lister T, Lowry S, Magnes W, Markkanen J, Martinez Navajas I, Martins Z, Matsuoka A, Matyjasiak B, Mazelle C, Mazzotta Epifani E, Meier M, Michaelis H, Micheli M, Migliorini A, Millet AL, Moreno F, Mottola S, Moutounaick B, Muinonen K, Müller DR, Murakami G, Murata N, Myszka K, Nakajima S, Nemeth Z, Nikolajev A, Nordera S, Ohlsson D, Olesk A, Ottacher H, Ozaki N, Oziol C, Patel M, Savio Paul A, Penttilä A, Pernechele C, Peterson J, Petraglio E, Piccirillo AM, Plaschke F, Polak S, Postberg F, Proosa H, Protopapa S, Puccio W, Ranvier S, Raymond S, Richter I, Rieder M, Rigamonti R, Ruiz Rodriguez I, Santolik O, Sasaki T, Schrödter R, Shirley K, Slavinskis A, Sodor B, Soucek J, Stephenson P, Stöckli L, Szewczyk P, Troznai G, Uhlir L, Usami N, Valavanoglou A, Vaverka J, Wang W, Wang XD, Wattieaux G, Wieser M, Wolf S, Yano H, Yoshikawa I, Zakharov V, Zawistowski T, Zuppella P, Rinaldi G, and Ji H
Abstract: Here we describe the novel, multi-point Comet Interceptor mission. It is dedicated to the exploration of a little-processed long-period comet, possibly entering the inner Solar System for the first time, or to encounter an interstellar object originating at another star. The objectives of the mission are to address the following questions: What are the surface composition, shape, morphology, and structure of the target object? What is the composition of the gas and dust in the coma, its connection to the nucleus, and the nature of its interaction with the solar wind? The mission was proposed to the European Space Agency in 2018, and formally adopted by the agency in June 2022, for launch in 2029 together with the Ariel mission. Comet Interceptor will take advantage of the opportunity presented by ESA's F-Class call for fast, flexible, low-cost missions to which it was proposed. The call required a launch to a halo orbit around the Sun-Earth L2 point. The mission can take advantage of this placement to wait for the discovery of a suitable comet reachable with its minimum Δ V capability of 600 ms - 1 . Comet Interceptor will be unique in encountering and studying, at a nominal closest approach distance of 1000 km, a comet that represents a near-pristine sample of material from the formation of the Solar System. It will also add a capability that no previous cometary mission has had, which is to deploy two sub-probes - B1, provided by the Japanese space agency, JAXA, and B2 - that will follow different trajectories through the coma. While the main probe passes at a nominal 1000 km distance, probes B1 and B2 will follow different chords through the coma at distances of 850 km and 400 km, respectively. The result will be unique, simultaneous, spatially resolved information of the 3-dimensional properties of the target comet and its interaction with the space environment. We present the mission's science background leading to these objectives, as well as an overview of the scientific instruments, mission design, and schedule., Competing Interests: Competing InterestsThe authors declare no competing interests., (© The Author(s) 2024.)
Published: 2024
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96. Ejecta from the DART-produced active asteroid Dimorphos.

Author: Li JY, Hirabayashi M, Farnham TL, Sunshine JM, Knight MM, Tancredi G, Moreno F, Murphy B, Opitom C, Chesley S, Scheeres DJ, Thomas CA, Fahnestock EG, Cheng AF, Dressel L, Ernst CM, Ferrari F, Fitzsimmons A, Ieva S, Ivanovski SL, Kareta T, Kolokolova L, Lister T, Raducan SD, Rivkin AS, Rossi A, Soldini S, Stickle AM, Vick A, Vincent JB, Weaver HA, Bagnulo S, Bannister MT, Cambioni S, Campo Bagatin A, Chabot NL, Cremonese G, Daly RT, Dotto E, Glenar DA, Granvik M, Hasselmann PH, Herreros I, Jacobson S, Jutzi M, Kohout T, La Forgia F, Lazzarin M, Lin ZY, Lolachi R, Lucchetti A, Makadia R, Mazzotta Epifani E, Michel P, Migliorini A, Moskovitz NA, Ormö J, Pajola M, Sánchez P, Schwartz SR, Snodgrass C, Steckloff J, Stubbs TJ, and Trigo-Rodríguez JM
Abstract: Some active asteroids have been proposed to be formed as a result of impact events 1 . Because active asteroids are generally discovered by chance only after their tails have fully formed, the process of how impact ejecta evolve into a tail has, to our knowledge, not been directly observed. The Double Asteroid Redirection Test (DART) mission of NASA 2 , in addition to having successfully changed the orbital period of Dimorphos 3 , demonstrated the activation process of an asteroid resulting from an impact under precisely known conditions. Here we report the observations of the DART impact ejecta with the Hubble Space Telescope from impact time T + 15 min to T + 18.5 days at spatial resolutions of around 2.1 km per pixel. Our observations reveal the complex evolution of the ejecta, which are first dominated by the gravitational interaction between the Didymos binary system and the ejected dust and subsequently by solar radiation pressure. The lowest-speed ejecta dispersed through a sustained tail that had a consistent morphology with previously observed asteroid tails thought to be produced by an impact 4,5 . The evolution of the ejecta after the controlled impact experiment of DART thus provides a framework for understanding the fundamental mechanisms that act on asteroids disrupted by a natural impact 1,6 ., (© 2023. The Author(s).)
Published: 2023
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97. Temperate Earth-sized planets transiting a nearby ultracool dwarf star.

Author: Gillon M, Jehin E, Lederer SM, Delrez L, de Wit J, Burdanov A, Van Grootel V, Burgasser AJ, Triaud AH, Opitom C, Demory BO, Sahu DK, Bardalez Gagliuffi D, Magain P, and Queloz D
Abstract: Star-like objects with effective temperatures of less than 2,700 kelvin are referred to as 'ultracool dwarfs'. This heterogeneous group includes stars of extremely low mass as well as brown dwarfs (substellar objects not massive enough to sustain hydrogen fusion), and represents about 15 per cent of the population of astronomical objects near the Sun. Core-accretion theory predicts that, given the small masses of these ultracool dwarfs, and the small sizes of their protoplanetary disks, there should be a large but hitherto undetected population of terrestrial planets orbiting them--ranging from metal-rich Mercury-sized planets to more hospitable volatile-rich Earth-sized planets. Here we report observations of three short-period Earth-sized planets transiting an ultracool dwarf star only 12 parsecs away. The inner two planets receive four times and two times the irradiation of Earth, respectively, placing them close to the inner edge of the habitable zone of the star. Our data suggest that 11 orbits remain possible for the third planet, the most likely resulting in irradiation significantly less than that received by Earth. The infrared brightness of the host star, combined with its Jupiter-like size, offers the possibility of thoroughly characterizing the components of this nearby planetary system.
Published: 2016
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