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2. Catalog for the ESPRESSO blind radial velocity exoplanet survey

Author

Hojjatpanah, S., primary, Figueira, P., additional, Santos, N. C., additional, Adibekyan, V., additional, Sousa, S. G., additional, Delgado-Mena, E., additional, Alibert, Y., additional, Cristiani, S., additional, González Hernández, J. I., additional, Lanza, A. F., additional, Di Marcantonio, P., additional, Martins, J. H. C., additional, Micela, G., additional, Molaro, P., additional, Neves, V., additional, Oshagh, M., additional, Pepe, F., additional, Poretti, E., additional, Rojas-Ayala, B., additional, Rebolo, R., additional, Suárez Mascareño, A., additional, and Zapatero Osorio, M. R., additional

Published
2019
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3. The HARPS search for southern extra-solar planets

Author

Bonfils, X., Lo Curto, G., Correia, A. C. M., Laskar, J., Udry, S., Delfosse, X., Forveille, T., Astudillo-Defru, N., Benz, Willy, Bouchy, F., Gillon, M., Hébrard, G., Lovis, C., Mayor, M., Moutou, C., Naef, D., Neves, V., Pepe, F., Perrier, C., Queloz, D., Santos, N. C., and Ségransan, D.

Subjects
530 Physics, 520 Astronomy, 620 Engineering
Abstract

The meter-per-second precision achieved by today’s velocimeters enables us to search for 1−10 M⊕ planets in the habitable zone of cool stars. This paper reports on the detection of three planets orbiting GJ 163 (HIP 19394), a M3 dwarf monitored by our ESO/HARPS search for planets. We made use of the HARPS spectrograph to collect 150 radial velocities of GJ 163 over a period of eight years. We searched the radial-velocity time series for coherent signals and found five distinct periodic variabilities. We investigated the stellar activity and called into question the planetary interpretation for two signals. Before more data can be acquired we concluded that at least three planets are orbiting GJ 163. They have orbital periods of Pb = 8.632 ± 0.002, Pc = 25.63 ± 0.03, and Pd = 604 ± 8 days and minimum masses msini = 10.6 ± 0.6, 6.8 ± 0.9, and 29 ± 3 M⊕, respectively. We hold our interpretations for the two additional signals with periods P(e) = 19.4 and P(f) = 108 days. The inner pair presents an orbital period ratio of 2.97, but a dynamical analysis of the system shows that it lays outside the 3:1 mean motion resonance. The planet GJ 163c, in particular, is a super-Earth with an equilibrium temperature of Teq = (302 ± 10)(1 − A)1/4 K and may lie in the so-called habitable zone for albedo values (A = 0.34 − 0.89) moderately higher than that of Earth (A⊕ = 0.2−0.3).

Published
2013
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4. A short-period super-Earth orbiting the M2.5 dwarf GJ 3634

Author

Bonfils, X., Gillon, M., Forveille, T., Delfosse, X., Deming, D., Demory, B.-O., Lovis, C., Mayor, M., Neves, V., Perrier, C., Santos, N. C., Seager, S., Udry, S., Boisse, I., and Bonnefoy, M.

Subjects
520 Astronomy
Abstract

We report on the detection of GJ 3634b, a super-Earth of mass and period P = 2.64561 ± 0.00066 day. Its host star is a M2.5 dwarf, has a mass of 0.45 ± 0.05 M⊙, a radius of 0.43 ± 0.03 R⊙ and lies 19.8 ± 0.6 pc away from our Sun. The planet is detected after a radial-velocity campaign using the ESO/Harps spectrograph. GJ 3634b had an a priori geometric probability to undergo transit of ~7% and, if telluric in composition, a non-grazing transit would produce a photometric dip of ≲0.1%. We therefore followed-up upon the RV detection with photometric observations using the 4.5-μm band of the IRAC imager onboard Spitzer. Our six-hour long light curve excludes that a transit occurs for 2σ of the probable transit window, decreasing the probability that GJ 3634b undergoes transit to ~0.5%.

Published
2011
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6. The variability behaviour of CoRoT M-giant stars

Author

Ferreira Lopes, C. E., primary, Neves, V., additional, Leão, I. C., additional, de Freitas, D. B., additional, Canto Martins, B. L., additional, da Costa, A. D., additional, Paz-Chinchón, F., additional, Das Chagas, M. L., additional, Baglin, A., additional, Janot-Pacheco, E., additional, and De Medeiros, J. R., additional

Published
2015
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7. Rotation period distribution of CoRoT andKeplerSun-like stars

Author

Leão, I. C., primary, Pasquini, L., additional, Ferreira Lopes, C. E., additional, Neves, V., additional, Valcarce, A. A. R., additional, de Oliveira, L. L. A., additional, Freire da Silva, D., additional, de Freitas, D. B., additional, Canto Martins, B. L., additional, Janot-Pacheco, E., additional, Baglin, A., additional, and De Medeiros, J. R., additional

Published
2015
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8. A HARPS view on K2-3

Author

Almenara, J. M., primary, Astudillo-Defru, N., additional, Bonfils, X., additional, Forveille, T., additional, Santerne, A., additional, Albrecht, S., additional, Barros, S. C. C., additional, Bouchy, F., additional, Delfosse, X., additional, Demangeon, O., additional, Diaz, R. F., additional, Hébrard, G., additional, Mayor, M., additional, Neves, V., additional, Rojo, P., additional, Santos, N. C., additional, and Wünsche, A., additional

Published
2015
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10. The HARPS search for southern extra-solar planets

Author

Astudillo-Defru, N., primary, Bonfils, X., additional, Delfosse, X., additional, Ségransan, D., additional, Forveille, T., additional, Bouchy, F., additional, Gillon, M., additional, Lovis, C., additional, Mayor, M., additional, Neves, V., additional, Pepe, F., additional, Perrier, C., additional, Queloz, D., additional, Rojo, P., additional, Santos, N. C., additional, and Udry, S., additional

Published
2015
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11. A global analysis ofSpitzerand new HARPS data confirms the loneliness and metal-richness of GJ 436 b

Author

Lanotte, A. A., primary, Gillon, M., additional, Demory, B.-O., additional, Fortney, J. J., additional, Astudillo, N., additional, Bonfils, X., additional, Magain, P., additional, Delfosse, X., additional, Forveille, T., additional, Lovis, C., additional, Mayor, M., additional, Neves, V., additional, Pepe, F., additional, Queloz, D., additional, Santos, N., additional, and Udry, S., additional

Published
2014
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13. Metallicity of M dwarfs

Author

Neves, V., primary, Bonfils, X., additional, Santos, N. C., additional, Delfosse, X., additional, Forveille, T., additional, Allard, F., additional, and Udry, S., additional

Published
2014
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14. SWEET-Cat: A catalogue of parameters for Stars With ExoplanETs

Author

Santos, N. C., primary, Sousa, S. G., additional, Mortier, A., additional, Neves, V., additional, Adibekyan, V., additional, Tsantaki, M., additional, Delgado Mena, E., additional, Bonfils, X., additional, Israelian, G., additional, Mayor, M., additional, and Udry, S., additional

Published
2013
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15. The HARPS search for southern extra-solar planets

Author

Bonfils, X., primary, Lo Curto, G., additional, Correia, A. C. M., additional, Laskar, J., additional, Udry, S., additional, Delfosse, X., additional, Forveille, T., additional, Astudillo-Defru, N., additional, Benz, W., additional, Bouchy, F., additional, Gillon, M., additional, Hébrard, G., additional, Lovis, C., additional, Mayor, M., additional, Moutou, C., additional, Naef, D., additional, Neves, V., additional, Pepe, F., additional, Perrier, C., additional, Queloz, D., additional, Santos, N. C., additional, and Ségransan, D., additional

Published
2013
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16. The HARPS search for southern extra-solar planets

Author

Delfosse, X., primary, Bonfils, X., additional, Forveille, T., additional, Udry, S., additional, Mayor, M., additional, Bouchy, F., additional, Gillon, M., additional, Lovis, C., additional, Neves, V., additional, Pepe, F., additional, Perrier, C., additional, Queloz, D., additional, Santos, N. C., additional, and Ségransan, D., additional

Published
2013
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17. Metallicity of M dwarfs

Author

Neves, V., primary, Bonfils, X., additional, Santos, N. C., additional, Delfosse, X., additional, Forveille, T., additional, Allard, F., additional, and Udry, S., additional

Published
2013
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18. Prized results from HARPS

Author

Bonfils, Xavier, primary, Bouchy, François, additional, Delfosse, X., additional, Forveille, T., additional, Gillon, M., additional, Lovis, C., additional, Mayor, M., additional, Neves, V., additional, Pepe, F., additional, Perrier, C., additional, Queloz, D., additional, Santos, N., additional, Ségransan, D., additional, and Udry, S., additional

Published
2013
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19. A hot Uranus transiting the nearby M dwarf GJ 3470

Author

Bonfils, X., primary, Gillon, M., additional, Udry, S., additional, Armstrong, D., additional, Bouchy, F., additional, Delfosse, X., additional, Forveille, T., additional, Fumel, A., additional, Jehin, E., additional, Lendl, M., additional, Lovis, C., additional, Mayor, M., additional, McCormac, J., additional, Neves, V., additional, Pepe, F., additional, Perrier, C., additional, Pollaco, D., additional, Queloz, D., additional, and Santos, N. C., additional

Published
2012
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20. Metallicity of M dwarfs

Author

Neves, V., primary, Bonfils, X., additional, Santos, N. C., additional, Delfosse, X., additional, Forveille, T., additional, Allard, F., additional, Natário, C., additional, Fernandes, C. S., additional, and Udry, S., additional

Published
2012
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21. A short-period super-Earth orbiting the M2.5 dwarf GJ 3634

Author

Bonfils, X., primary, Gillon, M., additional, Forveille, T., additional, Delfosse, X., additional, Deming, D., additional, Demory, B.-O., additional, Lovis, C., additional, Mayor, M., additional, Neves, V., additional, Perrier, C., additional, Santos, N. C., additional, Seager, S., additional, Udry, S., additional, Boisse, I., additional, and Bonnefoy, M., additional

Published
2011
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23. A global analysis of Spitzer and new HARPS data confirms the loneliness and metal-richness of GJ 436 b.

Author

Lanotte, A. A., Gillon, M., Demory, B.-O., Fortney, J. J., Astudillo, N., Bonfils, X., Magain, P., Delfosse, X., Forveille, T., Lovis, C., Mayor, M., Neves, V., Pepe, F., Queloz, D., Santos, N., and Udry, S.

Subjects
RADIAL velocity of stars, STARS, PLANETARY research, ASTRONOMICAL research, ASTROPHYSICS research
Abstract

Context. GJ 436b is one of the few transiting warm Neptunes for which a detailed characterisation of the atmosphere is possible, whereas its non-negligible orbital eccentricity calls for further investigation. Independent analyses of several individual datasets obtained with Spitzer have led to contradicting results attributed to the different techniques used to treat the instrumental effects. Aims. We aim at investigating these previous controversial results and developing our knowledge of the system based on the full Spitzer photometry dataset combined with new Doppler measurements obtained with the HARPS spectrograph. We also want to search for additional planets. Methods. We optimise aperture photometry techniques and the photometric deconvolution algorithm DECPHOT to improve the data reduction of the Spitzer photometry spanning wavelengths from 3-24 μm. Adding the high-precision HARPS radial velocity data, we undertake a Bayesian global analysis of the system considering both instrumental and stellar e ects on the flux variation. Results. We present a refined radius estimate of RP = 4:10 ± 0:16 R☉, mass MP = 25:4 ± 2:1 M☉, and eccentricity e = 0:162 ± 0:004 for GJ 436b. Our measured transit depths remain constant in time and wavelength, in disagreement with the results of previous studies. In addition, we find that the post-occultation flare-like structure at 3.6 μm that led to divergent results on the occultation depth measurement is spurious. We obtain occultation depths at 3.6, 5.8, and 8.0 μm that are shallower than in previous works, in particular at 3.6 μm. However, these depths still appear consistent with a metal-rich atmosphere depleted in methane and enhanced in CO/CO2, although perhaps less than previously thought. We could not detect a significant orbital modulation in the 8 μm phase curve. We find no evidence of a potential planetary companion, stellar activity, or a stellar spin-orbit misalignment. Conclusions. Recent theoretical models invoking high-metallicity atmospheres for warm Neptunes are a reasonable match to our results, but we encourage new modelling efforts based on our revised data. Future observations covering a wide wavelength range of GJ 436b and other Neptune-class exoplanets will further illuminate their atmosphere properties, whilst future accurate radial velocity measurements might explain the eccentricity. [ABSTRACT FROM AUTHOR]

Published
2014
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24. Near-infrared transmission spectrum of the warm-Uranus GJ 3470b with the Wide Field Camera-3 on the Hubble Space Telescope.

Author

Ehrenreich, D., Bonfils, X., Lovis, C., Delfosse, X., Forveille, T., Mayor, M., Neves, V., Santos, N. C., Udry, S., and Ségransan, D.

Subjects
NEAR infrared radiation, ATMOSPHERE of Uranus, RAYLEIGH scattering, SUPER-Earths, ASTRONOMICAL spectroscopy, THERMOCHEMISTRY
Abstract

The atmospheric composition of super-Earths and Neptunes is the object of intense observational and theoretical investigations. Transmission spectra recently obtained for such exoplanets are featureless in the near infrared. This flat signature is attributed to the presence of optically-thick clouds or translucent hazes. The planet GJ 3470b is a warm Neptune (or Uranus) detected in transit across a bright late-type star. The transit of this planet has already been observed in several band passes from the ground and space, allowing observers to draw an intriguing yet incomplete transmission spectrum of the planet atmospheric limb. In particular, published data in the visible suggest the existence of a Rayleigh scattering slope - making GJ 3470b a unique case among the known Neptunes, while data obtained beyond 2 μm are consistent with a flat infrared spectrum. The unexplored near-infrared spectral region between 1 μm and 2 μm, is thus the key to understanding the atmospheric nature of GJ 3470b. Here, we report on the first space-borne spectrum of GJ 3470, obtained during one transit of the planet with the Wide Field Camera-3 (WFC3) on board the Hubble Space Telescope (HST), operated in stare mode. The spectrum covers the 1.1-1.7 μm region with a resolution of ∼300 (Δλ ∼ 4 nm). We retrieve the transmission spectrum of GJ 3470b with a chromatic planet-to-star radius ratio precision of 0.09% (about half a scale height) per 40 nm bins. At this precision, the spectrum appears featureless, in good agreement with ground-based and Spitzer infrared data at longer wavelengths, pointing to a flat transmission spectrum from 1 μm to 5 μm. We present new simulations of possible theoretical transmission spectra for GJ 3470b, which allow us to show that the HST/WFC3 observations rule out cloudless hydrogenrich atmospheres (>10σ) as well as hydrogen-rich atmospheres with tholin haze (>5σ). Adding our near-infrared measurements to the full set of previously published data from 0.3 μm to 5 μm, we find that a cloudy, hydrogen-rich atmosphere can explain the full transmission spectrum: the tentative Rayleigh slope in the visible and the flat near-infrared spectrum can be both reproduced if the water volume mixing ratio is lower at the terminator than predicted by equilibrium thermochemistry models. [ABSTRACT FROM AUTHOR]

Published
2014
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25. The HARPS search for southern extra-solar planets

Author

Gillon, M., Bonfils, X., Santos, N. C., Moutou, C., Perrier, C., Ségransan, D., Delfosse, X., Udry, S., Queloz, D., Laskar, J., Bouchy, F., Lo Curto, G., Pepe, F., Naef, D., Correia, A. C. M., Hébrard, G., Benz, Willy, Astudillo-Defru, N., Lovis, C., Neves, V., Forveille, T., and Mayor, M.

Subjects
13. Climate action, 530 Physics, 520 Astronomy, 620 Engineering
Abstract

The meter-per-second precision achieved by today’s velocimeters enables us to search for 1−10 M⊕ planets in the habitable zone of cool stars. This paper reports on the detection of three planets orbiting GJ 163 (HIP 19394), a M3 dwarf monitored by our ESO/HARPS search for planets. We made use of the HARPS spectrograph to collect 150 radial velocities of GJ 163 over a period of eight years. We searched the radial-velocity time series for coherent signals and found five distinct periodic variabilities. We investigated the stellar activity and called into question the planetary interpretation for two signals. Before more data can be acquired we concluded that at least three planets are orbiting GJ 163. They have orbital periods of Pb = 8.632 ± 0.002, Pc = 25.63 ± 0.03, and Pd = 604 ± 8 days and minimum masses msini = 10.6 ± 0.6, 6.8 ± 0.9, and 29 ± 3 M⊕, respectively. We hold our interpretations for the two additional signals with periods P(e) = 19.4 and P(f) = 108 days. The inner pair presents an orbital period ratio of 2.97, but a dynamical analysis of the system shows that it lays outside the 3:1 mean motion resonance. The planet GJ 163c, in particular, is a super-Earth with an equilibrium temperature of Teq = (302 ± 10)(1 − A)1/4 K and may lie in the so-called habitable zone for albedo values (A = 0.34 − 0.89) moderately higher than that of Earth (A⊕ = 0.2−0.3).

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