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15 results on '"Qvam, J. K. T."'

1. Lens mass estimate in the Galactic disk extreme parallax microlensing event Gaia19dke

Author

Maskoliūnas, M., Wyrzykowski, Ł., Howil, K., Rybicki, K. A., Zieliński, P., Kaczmarek, Z., Kruszyńska, K., Jabłońska, M., Zdanavičius, J., Pakštienė, E., Čepas, V., Mikołajczyk, P. J., Janulis, R., Gromadzki, M., Ihanec, N., Adomavičienė, R., Šiškauskaitė, K., Bronikowski, M., Sivak, P., Stankevičiūtė, A., Sitek, M., Ratajczak, M., Pylypenko, U., Gezer, I., Awiphan, S., Bachelet, E., Bąkowska, K., Boyle, R. P., Bozza, V., Brincat, S. M., Burgaz, U., Butterley, T., Carrasco, J. M., Cassan, A., Cusano, F., Damljanovic, G., Davidson, J. W., Dhillon, V. S., Dominik, M., Dubois, F., Esenoglu, H. H., Jaimes, R. Figuera, Fukui, A., Galdies, C., Garofalo, A., Godunova, V., Güver, T., Heidt, J., Hundertmark, M., Izviekova, I., Joachimczyk, B., Kamińska, M. K., Kamiński, K., Kaptan, S., Kvernadze, T., Kvaratskhelia, O., Littlefair, S., Michniewicz, O., Nakhatutai, N., Ogłoza, W., Ohsawa, R., Olszewska, J. M., Polińska, M., Popowicz, A., Qvam, J. K. T., Radziwonowicz, M., Reichart, D. E., Słowikowska, A., Simon, A., Sonbas, E., Stojanovic, M., Tsapras, Y., Vanaverbeke, S., Wambsganss, J., Wilson, R. W., Żejmo, M., and Zola, S.

Subjects
Astrophysics - Solar and Stellar Astrophysics, Astrophysics - Astrophysics of Galaxies, Astrophysics - Instrumentation and Methods for Astrophysics
Abstract

We present the results of our analysis of Gaia19dke, an extraordinary microlensing event in the Cygnus constellation that was first spotted by the {\gaia} satellite. This event featured a strong microlensing parallax effect, which resulted in multiple peaks in the light curve. We conducted extensive photometric, spectroscopic, and high-resolution imaging follow-up observations to determine the mass and the nature of the invisible lensing object. Using the Milky Way priors on density and velocity of lenses, we found that the dark lens is likely to be located at a distance of $D_L =(3.05^{+4.10}_{-2.42})$kpc, and has a mass of $M_L =(0.51^{+3.07}_{-0.40}) M_\odot$. Based on its low luminosity and mass, we propose that the lens in Gaia19dke event is an isolated white dwarf., Comment: 16 pages, submitted to A&A

Published
2023

2. Massive search of spot- and facula-crossing events in 1598 exoplanetary transit lightcurves

Author

Baluev, R. V., Sokov, E. N., Sokova, I. A., Shaidulin, V. Sh., Veselova, A. V., Aitov, V. N., Mitiani, G. Sh., Valeev, A. F., Gadelshin, D. R., Gutaev, A. G., Beskin, G. M., Valyavin, G. G., Antonyuk, K., Barkaoui, K., Gillon, M., Jehin, E., Delrez, L., Guðmundsson, S., Dale, H. A., Fernández-Lajús, E., Di Sisto, R. P., Bretton, M., Wunsche, A., Hentunen, V. -P., Shadick, S., Jongen, Y., Kang, W., Kim, T., Pakštienė, E., Qvam, J. K. T., Knight, C. R., Guerra, P., Marchini, A., Salvaggio, F., Papini, R., Evans, P., Salisbury, M., Garlitz, J., Esseiva, N., Ogmen, Y., Bosch-Cabot, P., Selezneva, A., and Hinse, T. C.

Subjects
Astrophysics - Earth and Planetary Astrophysics, Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - Solar and Stellar Astrophysics
Abstract

We developed a dedicated statistical test for a massive detection of spot- and facula-crossing anomalies in multiple exoplanetary transit lightcurves, based on the frequentist $p$-value thresholding. This test was used to augment our algorithmic pipeline for transit lightcurves analysis. It was applied to $1598$ amateur and professional transit observations of $26$ targets being monitored in the EXPANSION project. We detected $109$ statistically significant candidate events revealing a roughly $2:1$ asymmetry in favor of spots-crossings over faculae-crossings. Although some candidate anomalies likely appear non-physical and originate from systematic errors, such asymmetry between negative and positive events should indicate a physical difference between the frequency of star spots and faculae. Detected spot-crossing events also reveal positive correlation between their amplitude and width, possibly owed to spot size correlation. However, the frequency of all detectable crossing events appears just about a few per cent, so they cannot explain excessive transit timing noise observed for several targets., Comment: 30 pages, 9 figures, 1 table; accepted by Acta Astronomica

Published
2021
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3. Homogeneously derived transit timings for 17 exoplanets and reassessed TTV trends for WASP-12 and WASP-4

Author

Baluev, R. V., Sokov, E. N., Jones, H. R. A., Shaidulin, V. Sh., Sokova, I. A., Nielsen, L. D., Benni, P., Schneiter, E. M., D'Angelo, C. Villarreal, Fernández-Lajús, E., Di Sisto, R. P., Baştürk, Ö., Bretton, M., Wunsche, A., Hentunen, V. -P., Shadick, S., Jongen, Y., Kang, W., Kim, T., Pakštienė, E., Qvam, J. K. T., Knight, C. R., Guerra, P., Marchini, A., Salvaggio, F., Papini, R., Evans, P., Salisbury, M., Garcia, F., Molina, D., Garlitz, J., Esseiva, N., Ogmen, Y., Karavaev, Yu., Rusov, S., Ibrahimov, M. A., and Karimov, R. G.

Subjects
Astrophysics - Earth and Planetary Astrophysics
Abstract

We homogeneously analyse $\sim 3.2\times 10^5$ photometric measurements for $\sim 1100$ transit lightcurves belonging to $17$ exoplanet hosts. The photometric data cover $16$ years 2004--2019 and include amateur and professional observations. Old archival lightcurves were reprocessed using up-to-date exoplanetary parameters and empirically debiased limb-darkening models. We also derive self-consistent transit and radial-velocity fits for $13$ targets. We confirm the nonlinear TTV trend in the WASP-12 data at a high significance, and with a consistent magnitude. However, Doppler data reveal hints of a radial acceleration about $(-7.5\pm 2.2)$~m/s/yr, indicating the presence of unseen distant companions, and suggesting that roughly $10$ per cent of the observed TTV was induced via the light-travel (or Roemer) effect. For WASP-4, a similar TTV trend suspected after the recent TESS observations appears controversial and model-dependent. It is not supported by our homogeneus TTV sample, including $10$ ground-based EXPANSION lightcurves obtained in 2018 simultaneously with TESS. Even if the TTV trend itself does exist in WASP-4, its magnitude and tidal nature are uncertain. Doppler data cannot entirely rule out the Roemer effect induced by possible distant companions., Comment: 19 pages, 4 figures, 6 tables; revised manuscript submitted to MNRAS; online-only supplements are in the download archive

Published
2019
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4. Search for variable stars in the northern sky:Analysis of photometric time series for 3598 stars

Author

Pakštienė, E., Janulis, R., Drazdauskas, A., Mikolaitis, Š., Tautvaišienė, G., Minkevičiutė, R., Bagdonas, V., Klebonas, L., and Qvam, J. K. T.

Subjects
Astrophysics - Solar and Stellar Astrophysics
Abstract

As extensive ground-based observations and characterisation of different variable stars are of the utmost importance in preparing optimal input catalogues for space missions, our aim was to search for new variable stars in selected fields of the northern sky. We obtained 24470 CCD images and analysed photometric time series of stars using the DAOPHOT based package Muniwin as the first step, and the Period04 package was used to further analyse the suspected new variable stars. The light curves and other observational results are presented for 3598 stars online. We found 81 new variable stars, among them is an eclipsing binary with a variable component and possibly eccentric orbits TYC4038-693-1 which we also observed spectroscopically, four {\delta} Scuti candidates, six other variable stars with periods falling into the interval of 35 minutes to 20 days. Furthermore, we identified 70 slowly varying stars with so far undefined periodicity. Additional photometric and spectral observations were carried out for TYC 2764-1997-1, and its previous candidacy for eclipsing binaries was approved., Comment: 17 pages, 13 figures. Accepted to Astrophysics and Space Science. Manuscript number ASTR-D-18-00575R2

Published
2019
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5. Diagnosing the Clumpy Protoplanetary Disk of the UXor Type Young Star GM Cephei

Author

Huang, P. C., Chen, W. P., Mugrauer, M., Bischoff, R., Budaj, J., Burkhonov, O., Ehgamberdiev, S., Errmann, R., Garai, Z., Hsiao, H. Y., Janulis, R., Jensen, E. L. N., Kiyota, S., Kuramoto, K., Lin, C. S., Lin, H. C., Liu, J. Z, Lux, O., Naito, H., Neuhäuser, R., Ohlert, J., Pakštienė, E., Pribulla, T., Qvam, J. K. T., Raetz, St., Sato, S., Schwartz, M., Semkov, E., Takagi, S., Wagner, D., Watanabe, M., and Zhang, Y.

Subjects
Astrophysics - Solar and Stellar Astrophysics
Abstract

UX Orionis stars (UXors) are Herbig Ae/Be or T Tauri stars exhibiting sporadic occultation of stellar light by circumstellar dust. GM\,Cephei is such a UXor in the young ($\sim4$~Myr) open cluster Trumpler\,37, showing prominent infrared excess, emission-line spectra, and flare activity. Our photometric monitoring (2008--2018) detects (1)~an $\sim$3.43~day period, likely arising from rotational modulation by surface starspots, (2)~sporadic brightening on time scales of days due to accretion, (3)~irregular minor flux drops due to circumstellar dust extinction, and (4)~major flux drops, each lasting for a couple of months with a recurrence time, though not exactly periodic, of about two years. The star experiences normal reddening by large grains, i.e., redder when dimmer, but exhibits an unusual "blueing" phenomenon in that the star turns blue near brightness minima. The maximum extinction during relatively short (lasting $\leq 50$~days) events, is proportional to the duration, a consequence of varying clump sizes. For longer events, the extinction is independent of duration, suggestive of a transverse string distribution of clumps. Polarization monitoring indicates an optical polarization varying $\sim3\%$--8$\%$, with the level anticorrelated with the slow brightness change. Temporal variation of the unpolarized and polarized light sets constraints on the size and orbital distance of the circumstellar clumps in the interplay with the young star and scattering envelope. These transiting clumps are edge-on manifestations of the ring- or spiral-like structures found recently in young stars with imaging in infrared of scattered light, or in submillimeter of thermalized dust emission., Comment: 20 pages, 9 figures

Published
2019
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6. Full orbital solution for the binary system in the northern Galactic disc microlensing event Gaia16aye

Author

Wyrzykowski, Łukasz, Mróz, P., Rybicki, K. A., Gromadzki, M., Kołaczkowski, Z., Zieliński, M., Zieliński, P., Britavskiy, N., Gomboc, A., Sokolovsky, K., Hodgkin, S. T., Abe, L., Aldi, G. F., AlMannaei, A., Altavilla, G., Qasim, A. Al, Anupama, G. C., Awiphan, S., Bachelet, E., Bakıs, V., Baker, S., Bartlett, S., Bendjoya, P., Benson, K., Bikmaev, I. F., Birenbaum, G., Blagorodnova, N., Blanco-Cuaresma, S., Boeva, S., Bonanos, A. Z., Bozza, V., Bramich, D. M., Bruni, I., Burenin, R. A., Burgaz, U., Butterley, T., Caines, H. E., Caton, D. B., Novati, S. Calchi, Carrasco, J. M., Cassan, A., Cepas, V., Cropper, M., Chruślińska, M., Clementini, G., Clerici, A., Conti, D., Conti, M., Cross, S., Cusano, F., Damljanovic, G., Dapergolas, A., D'Ago, G., de Bruijne, J. H. J., Dennefeld, M., Dhillon, V. S., Dominik, M., Dziedzic, J., Ereceantalya, O., Eselevich, M. V., Esenoglu, H., Eyer, L., Jaimes, R. Figuera, Fossey, S. J., Galeev, A. I., Grebenev, S. A., Gupta, A. C., Gutaev, A. G., Hallakoun, N., Hamanowicz, A., Han, C., Handzlik, B., Haislip, J. B., Hanlon, L., Hardy, L. K., Harrison, D. L., van Heerden, H. J., Hoette, V. L., Horne, K., Hudec, R., Hundertmark, M., Ihanec, N., Irtuganov, E. N., Itoh, R., Iwanek, P., Jovanovic, M. D., Janulis, R., Jelínek, M., Jensen, E., Kaczmarek, Z., Katz, D., Khamitov, I. M., Kilic, Y., Klencki, J., Kolb, U., Kopacki, G., Kouprianov, V. V., Kruszyńska, K., Kurowski, S., Latev, G., Lee, C-H., Leonini, S., Leto, G., Lewis, F., Li, Z., Liakos, A., Littlefair, S. P., Lu, J., Manser, C. J., Mao, S., Maoz, D., Martin-Carrillo, A., Marais, J. P., Maskoliūnas, M., Maund, J. R., Meintjes, P. J., Melnikov, S. S., Ment, K., Mikołajczyk, P., Morrell, M., Mowlavi, N., Moździerski, D., Murphy, D., Nazarov, S., Netzel, H., Nesci, R., Ngeow, C. -C., Norton, A. J., Ofek, E. O., Pakstienė, E., Palaversa, L., Pandey, A., Paraskeva, E., Pawlak, M., Penny, M. T., Penprase, B. E., Piascik, A., Prieto, J. L., Qvam, J. K. T., Ranc, C., Rebassa-Mansergas, A., Reichart, D. E., Reig, P., Rhodes, L., Rivet, J. -P., Rixon, G., Roberts, D., Rosi, P., Russell, D. M., Sanchez, R. Zanmar, Scarpetta, G., Seabroke, G., Shappee, B. J., Schmidt, R., Shvartzvald, Y., Sitek, M., Skowron, J., Śniegowska, M., Snodgrass, C., Soares, P. S., van Soelen, B., Spetsieri, Z. T., Stankeviciūtė, A., Steele, I. A., Street, R. A., Strobl, J., Strubble, E., Szegedi, H., Ramirez, L. M. Tinjaca, Tomasella, L., Tsapras, Y., Vernet, D., Villanueva Jr., S., Vince, O., Wambsganss, J., van der Westhuizen, I. P., Wiersema, K., Wium, D., Wilson, R. W., Yoldas, A., Zhuchkov, R. Ya., Zhukov, D. G., Zdanavicius, J., Zoła, S., and Zubareva, A.

Subjects
Astrophysics - Solar and Stellar Astrophysics, Astrophysics - Instrumentation and Methods for Astrophysics
Abstract

Gaia16aye was a binary microlensing event discovered in the direction towards the northern Galactic disc and was one of the first microlensing events detected and alerted to by the Gaia space mission. Its light curve exhibited five distinct brightening episodes, reaching up to I=12 mag, and it was covered in great detail with almost 25,000 data points gathered by a network of telescopes. We present the photometric and spectroscopic follow-up covering 500 days of the event evolution. We employed a full Keplerian binary orbit microlensing model combined with the motion of Earth and Gaia around the Sun to reproduce the complex light curve. The photometric data allowed us to solve the microlensing event entirely and to derive the complete and unique set of orbital parameters of the binary lensing system. We also report on the detection of the first-ever microlensing space-parallax between the Earth and Gaia located at L2. The properties of the binary system were derived from microlensing parameters, and we found that the system is composed of two main-sequence stars with masses 0.57$\pm$0.05 $M_\odot$ and 0.36$\pm$0.03 $M_\odot$ at 780 pc, with an orbital period of 2.88 years and an eccentricity of 0.30. We also predict the astrometric microlensing signal for this binary lens as it will be seen by Gaia as well as the radial velocity curve for the binary system. Events such as Gaia16aye indicate the potential for the microlensing method of probing the mass function of dark objects, including black holes, in directions other than that of the Galactic bulge. This case also emphasises the importance of long-term time-domain coordinated observations that can be made with a network of heterogeneous telescopes., Comment: accepted for publication in A&A, 24 pages, 10 figures, tables with the data will be available electronically

Published
2019
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8. Full orbital solution for the binary system in the northern Galactic disc microlensing event Gaia16aye

Author

Wyrzykowski, Ł., primary, Mróz, P., additional, Rybicki, K. A., additional, Gromadzki, M., additional, Kołaczkowski, Z., additional, Zieliński, M., additional, Zieliński, P., additional, Britavskiy, N., additional, Gomboc, A., additional, Sokolovsky, K., additional, Hodgkin, S. T., additional, Abe, L., additional, Aldi, G. F., additional, AlMannaei, A., additional, Altavilla, G., additional, Al Qasim, A., additional, Anupama, G. C., additional, Awiphan, S., additional, Bachelet, E., additional, Bakış, V., additional, Baker, S., additional, Bartlett, S., additional, Bendjoya, P., additional, Benson, K., additional, Bikmaev, I. F., additional, Birenbaum, G., additional, Blagorodnova, N., additional, Blanco-Cuaresma, S., additional, Boeva, S., additional, Bonanos, A. Z., additional, Bozza, V., additional, Bramich, D. M., additional, Bruni, I., additional, Burenin, R. A., additional, Burgaz, U., additional, Butterley, T., additional, Caines, H. E., additional, Caton, D. B., additional, Calchi Novati, S., additional, Carrasco, J. M., additional, Cassan, A., additional, Čepas, V., additional, Cropper, M., additional, Chruślińska, M., additional, Clementini, G., additional, Clerici, A., additional, Conti, D., additional, Conti, M., additional, Cross, S., additional, Cusano, F., additional, Damljanovic, G., additional, Dapergolas, A., additional, D’Ago, G., additional, de Bruijne, J. H. J., additional, Dennefeld, M., additional, Dhillon, V. S., additional, Dominik, M., additional, Dziedzic, J., additional, Erece, O., additional, Eselevich, M. V., additional, Esenoglu, H., additional, Eyer, L., additional, Figuera Jaimes, R., additional, Fossey, S. J., additional, Galeev, A. I., additional, Grebenev, S. A., additional, Gupta, A. C., additional, Gutaev, A. G., additional, Hallakoun, N., additional, Hamanowicz, A., additional, Han, C., additional, Handzlik, B., additional, Haislip, J. B., additional, Hanlon, L., additional, Hardy, L. K., additional, Harrison, D. L., additional, van Heerden, H. J., additional, Hoette, V. L., additional, Horne, K., additional, Hudec, R., additional, Hundertmark, M., additional, Ihanec, N., additional, Irtuganov, E. N., additional, Itoh, R., additional, Iwanek, P., additional, Jovanovic, M. D., additional, Janulis, R., additional, Jelínek, M., additional, Jensen, E., additional, Kaczmarek, Z., additional, Katz, D., additional, Khamitov, I. M., additional, Kilic, Y., additional, Klencki, J., additional, Kolb, U., additional, Kopacki, G., additional, Kouprianov, V. V., additional, Kruszyńska, K., additional, Kurowski, S., additional, Latev, G., additional, Lee, C.-H., additional, Leonini, S., additional, Leto, G., additional, Lewis, F., additional, Li, Z., additional, Liakos, A., additional, Littlefair, S. P., additional, Lu, J., additional, Manser, C. J., additional, Mao, S., additional, Maoz, D., additional, Martin-Carrillo, A., additional, Marais, J. P., additional, Maskoliūnas, M., additional, Maund, J. R., additional, Meintjes, P. J., additional, Melnikov, S. S., additional, Ment, K., additional, Mikołajczyk, P., additional, Morrell, M., additional, Mowlavi, N., additional, Moździerski, D., additional, Murphy, D., additional, Nazarov, S., additional, Netzel, H., additional, Nesci, R., additional, Ngeow, C.-C., additional, Norton, A. J., additional, Ofek, E. O., additional, Pakštienė, E., additional, Palaversa, L., additional, Pandey, A., additional, Paraskeva, E., additional, Pawlak, M., additional, Penny, M. T., additional, Penprase, B. E., additional, Piascik, A., additional, Prieto, J. L., additional, Qvam, J. K. T., additional, Ranc, C., additional, Rebassa-Mansergas, A., additional, Reichart, D. E., additional, Reig, P., additional, Rhodes, L., additional, Rivet, J.-P., additional, Rixon, G., additional, Roberts, D., additional, Rosi, P., additional, Russell, D. M., additional, Zanmar Sanchez, R., additional, Scarpetta, G., additional, Seabroke, G., additional, Shappee, B. J., additional, Schmidt, R., additional, Shvartzvald, Y., additional, Sitek, M., additional, Skowron, J., additional, Śniegowska, M., additional, Snodgrass, C., additional, Soares, P. S., additional, van Soelen, B., additional, Spetsieri, Z. T., additional, Stankevičiūtė, A., additional, Steele, I. A., additional, Street, R. A., additional, Strobl, J., additional, Strubble, E., additional, Szegedi, H., additional, Tinjaca Ramirez, L. M., additional, Tomasella, L., additional, Tsapras, Y., additional, Vernet, D., additional, Villanueva, S., additional, Vince, O., additional, Wambsganss, J., additional, van der Westhuizen, I. P., additional, Wiersema, K., additional, Wium, D., additional, Wilson, R. W., additional, Yoldas, A., additional, Zhuchkov, R. Ya., additional, Zhukov, D. G., additional, Zdanavičius, J., additional, Zoła, S., additional, and Zubareva, A., additional

Published
2020
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9. Homogeneously derived transit timings for 17 exoplanets and reassessed TTV trends for WASP-12 and WASP-4

Author

Baluev, R V, primary, Sokov, E N, additional, Jones, H R A, additional, Shaidulin, V Sh, additional, Sokova, I A, additional, Nielsen, L D, additional, Benni, P, additional, Schneiter, E M, additional, Villarreal D’Angelo, C, additional, Fernández-Lajús, E, additional, Di Sisto, R P, additional, Baştürk, Ö, additional, Bretton, M, additional, Wunsche, A, additional, Hentunen, V-P, additional, Shadick, S, additional, Jongen, Y, additional, Kang, W, additional, Kim, T, additional, Pakštienė, E, additional, Qvam, J K T, additional, Knight, C R, additional, Guerra, P, additional, Marchini, A, additional, Salvaggio, F, additional, Papini, R, additional, Evans, P, additional, Salisbury, M, additional, Garcia, F, additional, Molina, D, additional, Garlitz, J, additional, Esseiva, N, additional, Ogmen, Y, additional, Karavaev, Yu, additional, Rusov, S, additional, Ibrahimov, M A, additional, and Karimov, R G, additional

Published
2019
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11. Diagnosing the Clumpy Protoplanetary Disk of the UXor Type Young Star GM Cephei

Author

Huang, P. C., primary, Chen, W. P., additional, Mugrauer, M., additional, Bischoff, R., additional, Budaj, J., additional, Burkhonov, O., additional, Ehgamberdiev, S., additional, Errmann, R., additional, Garai, Z., additional, Hsiao, H. Y., additional, Hu, C. L., additional, Janulis, R., additional, Jensen, E. L. N., additional, Kiyota, S., additional, Kuramoto, K., additional, Lin, C. S., additional, Lin, H. C., additional, Liu, J. Z., additional, Lux, O., additional, Naito, H., additional, Neuhäuser, R., additional, Ohlert, J., additional, Pakštienė, E., additional, Pribulla, T., additional, Qvam, J. K. T., additional, Raetz, St., additional, Sato, S., additional, Schwartz, M., additional, Semkov, E., additional, Takagi, S., additional, Wagner, D., additional, Watanabe, M., additional, and Zhang, Yu, additional

Published
2019
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12. Full orbital solution for the binary system in the northern Galactic disc microlensing event Gaia16aye

Author

Wyrzykowski, Ł., Mróz, P., Rybicki, K. A., Gromadzki, M., Kołaczkowski, Z., Zieliński, M., Zieliński, P., Britavskiy, N., Gomboc, A., Sokolovsky, K., Hodgkin, S. T., Abe, L., Aldi, G. F., AlMannaei, A., Altavilla, G., Al Qasim, A., Anupama, G. C., Awiphan, S., Bachelet, E., Bakış, V., Baker, S., Bartlett, S., Bendjoya, P., Benson, K., Bikmaev, I. F., Birenbaum, G., Blagorodnova, N., Blanco-Cuaresma, S., Boeva, S., Bonanos, A. Z., Bozza, V., Bramich, D. M., Bruni, I., Burenin, R. A., Burgaz, U., Butterley, T., Caines, H. E., Caton, D. B., Calchi Novati, S., Carrasco, J. M., Cassan, A., Čepas, V., Cropper, M., Chruślińska, M., Clementini, G., Clerici, A., Conti, D., Conti, M., Cross, S., Cusano, F., Damljanovic, G., Dapergolas, A., D’Ago, G., de Bruijne, J. H. J., Dennefeld, M., Dhillon, V. S., Dominik, M., Dziedzic, J., Erece, O., Eselevich, M. V., Esenoglu, H., Eyer, L., Figuera Jaimes, R., Fossey, S. J., Galeev, A. I., Grebenev, S. A., Gupta, A. C., Gutaev, A. G., Hallakoun, N., Hamanowicz, A., Han, C., Handzlik, B., Haislip, J. B., Hanlon, L., Hardy, L. K., Harrison, D. L., van Heerden, H. J., Hoette, V. L., Horne, K., Hudec, R., Hundertmark, M., Ihanec, N., Irtuganov, E. N., Itoh, R., Iwanek, P., Jovanovic, M. D., Janulis, R., Jelínek, M., Jensen, E., Kaczmarek, Z., Katz, D., Khamitov, I. M., Kilic, Y., Klencki, J., Kolb, U., Kopacki, G., Kouprianov, V. V., Kruszyńska, K., Kurowski, S., Latev, G., Lee, C.-H., Leonini, S., Leto, G., Lewis, F., Li, Z., Liakos, A., Littlefair, S. P., Lu, J., Manser, C. J., Mao, S., Maoz, D., Martin-Carrillo, A., Marais, J. P., Maskoliūnas, M., Maund, J. R., Meintjes, P. J., Melnikov, S. S., Ment, K., Mikołajczyk, P., Morrell, M., Mowlavi, N., Moździerski, D., Murphy, D., Nazarov, S., Netzel, H., Nesci, R., Ngeow, C.-C., Norton, A. J., Ofek, E. O., Pakštienė, E., Palaversa, L., Pandey, A., Paraskeva, E., Pawlak, M., Penny, M. T., Penprase, B. E., Piascik, A., Prieto, J. L., Qvam, J. K. T., Ranc, C., Rebassa-Mansergas, A., Reichart, D. E., Reig, P., Rhodes, L., Rivet, J.-P., Rixon, G., Roberts, D., Rosi, P., Russell, D. M., Zanmar Sanchez, R., Scarpetta, G., Seabroke, G., Shappee, B. J., Schmidt, R., Shvartzvald, Y., Sitek, M., Skowron, J., Śniegowska, M., Snodgrass, C., Soares, P. S., van Soelen, B., Spetsieri, Z. T., Stankevičiūtė, A., Steele, I. A., Street, R. A., Strobl, J., Strubble, E., Szegedi, H., Tinjaca Ramirez, L. M., Tomasella, L., Tsapras, Y., Vernet, D., Villanueva, S., Vince, O., Wambsganss, J., van der Westhuizen, I. P., Wiersema, K., Wium, D., Wilson, R. W., Yoldas, A., Zhuchkov, R. Ya., Zhukov, D. G., Zdanavičius, J., Zoła, S., Zubareva, A., Wyrzykowski, Ł., Mróz, P., Rybicki, K. A., Gromadzki, M., Kołaczkowski, Z., Zieliński, M., Zieliński, P., Britavskiy, N., Gomboc, A., Sokolovsky, K., Hodgkin, S. T., Abe, L., Aldi, G. F., AlMannaei, A., Altavilla, G., Al Qasim, A., Anupama, G. C., Awiphan, S., Bachelet, E., Bakış, V., Baker, S., Bartlett, S., Bendjoya, P., Benson, K., Bikmaev, I. F., Birenbaum, G., Blagorodnova, N., Blanco-Cuaresma, S., Boeva, S., Bonanos, A. Z., Bozza, V., Bramich, D. M., Bruni, I., Burenin, R. A., Burgaz, U., Butterley, T., Caines, H. E., Caton, D. B., Calchi Novati, S., Carrasco, J. M., Cassan, A., Čepas, V., Cropper, M., Chruślińska, M., Clementini, G., Clerici, A., Conti, D., Conti, M., Cross, S., Cusano, F., Damljanovic, G., Dapergolas, A., D’Ago, G., de Bruijne, J. H. J., Dennefeld, M., Dhillon, V. S., Dominik, M., Dziedzic, J., Erece, O., Eselevich, M. V., Esenoglu, H., Eyer, L., Figuera Jaimes, R., Fossey, S. J., Galeev, A. I., Grebenev, S. A., Gupta, A. C., Gutaev, A. G., Hallakoun, N., Hamanowicz, A., Han, C., Handzlik, B., Haislip, J. B., Hanlon, L., Hardy, L. K., Harrison, D. L., van Heerden, H. J., Hoette, V. L., Horne, K., Hudec, R., Hundertmark, M., Ihanec, N., Irtuganov, E. N., Itoh, R., Iwanek, P., Jovanovic, M. D., Janulis, R., Jelínek, M., Jensen, E., Kaczmarek, Z., Katz, D., Khamitov, I. M., Kilic, Y., Klencki, J., Kolb, U., Kopacki, G., Kouprianov, V. V., Kruszyńska, K., Kurowski, S., Latev, G., Lee, C.-H., Leonini, S., Leto, G., Lewis, F., Li, Z., Liakos, A., Littlefair, S. P., Lu, J., Manser, C. J., Mao, S., Maoz, D., Martin-Carrillo, A., Marais, J. P., Maskoliūnas, M., Maund, J. R., Meintjes, P. J., Melnikov, S. S., Ment, K., Mikołajczyk, P., Morrell, M., Mowlavi, N., Moździerski, D., Murphy, D., Nazarov, S., Netzel, H., Nesci, R., Ngeow, C.-C., Norton, A. J., Ofek, E. O., Pakštienė, E., Palaversa, L., Pandey, A., Paraskeva, E., Pawlak, M., Penny, M. T., Penprase, B. E., Piascik, A., Prieto, J. L., Qvam, J. K. T., Ranc, C., Rebassa-Mansergas, A., Reichart, D. E., Reig, P., Rhodes, L., Rivet, J.-P., Rixon, G., Roberts, D., Rosi, P., Russell, D. M., Zanmar Sanchez, R., Scarpetta, G., Seabroke, G., Shappee, B. J., Schmidt, R., Shvartzvald, Y., Sitek, M., Skowron, J., Śniegowska, M., Snodgrass, C., Soares, P. S., van Soelen, B., Spetsieri, Z. T., Stankevičiūtė, A., Steele, I. A., Street, R. A., Strobl, J., Strubble, E., Szegedi, H., Tinjaca Ramirez, L. M., Tomasella, L., Tsapras, Y., Vernet, D., Villanueva, S., Vince, O., Wambsganss, J., van der Westhuizen, I. P., Wiersema, K., Wium, D., Wilson, R. W., Yoldas, A., Zhuchkov, R. Ya., Zhukov, D. G., Zdanavičius, J., Zoła, S., and Zubareva, A.

Abstract

Gaia16aye was a binary microlensing event discovered in the direction towards the northern Galactic disc and was one of the first microlensing events detected and alerted to by the Gaia space mission. Its light curve exhibited five distinct brightening episodes, reaching up to I = 12 mag, and it was covered in great detail with almost 25 000 data points gathered by a network of telescopes. We present the photometric and spectroscopic follow-up covering 500 days of the event evolution. We employed a full Keplerian binary orbit microlensing model combined with the motion of Earth and Gaia around the Sun to reproduce the complex light curve. The photometric data allowed us to solve the microlensing event entirely and to derive the complete and unique set of orbital parameters of the binary lensing system. We also report on the detection of the first-ever microlensing space-parallax between the Earth and Gaia located at L2. The properties of the binary system were derived from microlensing parameters, and we found that the system is composed of two main-sequence stars with masses 0.57 ± 0.05 M⊙ and 0.36 ± 0.03 M⊙ at 780 pc, with an orbital period of 2.88 years and an eccentricity of 0.30. We also predict the astrometric microlensing signal for this binary lens as it will be seen by Gaia as well as the radial velocity curve for the binary system. Events such as Gaia16aye indicate the potential for the microlensing method of probing the mass function of dark objects, including black holes, in directions other than that of the Galactic bulge. This case also emphasises the importance of long-term time-domain coordinated observations that can be made with a network of heterogeneous telescopes.

13. Homogeneously derived transit timings for 17 exoplanets and reassessed TTV trends for WASP-12 and WASP-4

Author

Baluev, R V, Sokov, E N, Jones, H R A, Shaidulin, V Sh, Sokova, I A, Nielsen, L D, Benni, P, Schneiter, E M, D’Angelo, C Villarreal, Fernández-Lajús, E, Di Sisto, R P, Baştürk, Ö, Bretton, M, Wunsche, A, Hentunen, V-P, Shadick, S, Jongen, Y, Kang, W, Kim, T, Pakštienė, E, Qvam, J K T, Knight, C R, Guerra, P, Marchini, A, Salvaggio, F, Papini, R, Evans, P, Salisbury, M., Garcia, F, Molina, D, Garlitz, J, Esseiva, N, Ogmen, Y, Karavaev, Yu, Rusov, S, Ibrahimov, M A, Karimov, R G, Baluev, R V, Sokov, E N, Jones, H R A, Shaidulin, V Sh, Sokova, I A, Nielsen, L D, Benni, P, Schneiter, E M, D’Angelo, C Villarreal, Fernández-Lajús, E, Di Sisto, R P, Baştürk, Ö, Bretton, M, Wunsche, A, Hentunen, V-P, Shadick, S, Jongen, Y, Kang, W, Kim, T, Pakštienė, E, Qvam, J K T, Knight, C R, Guerra, P, Marchini, A, Salvaggio, F, Papini, R, Evans, P, Salisbury, M., Garcia, F, Molina, D, Garlitz, J, Esseiva, N, Ogmen, Y, Karavaev, Yu, Rusov, S, Ibrahimov, M A, and Karimov, R G

Abstract

We homogeneously analyse ∼3.2 × 105 photometric measurements for ∼1100 transit lightcurves belonging to 17 exoplanet hosts. The photometric data cover 16 years 2004–2019 and include amateur and professional observations. Old archival lightcurves were reprocessed using up-to-date exoplanetary parameters and empirically debiased limb-darkening models. We also derive self-consistent transit and radial-velocity fits for 13 targets. We confirm the nonlinear TTV trend in the WASP-12 data at a high significance, and with a consistent magnitude. However, Doppler data reveal hints of a radial acceleration about ( − 7.5 ± 2.2) m/s/yr, indicating the presence of unseen distant companions, and suggesting that roughly 10 per cent of the observed TTV was induced via the light-travel (or Roemer) effect. For WASP-4, a similar TTV trend suspected after the recent TESS observations appears controversial and model-dependent. It is not supported by our homogeneus TTV sample, including 10 ground-based EXPANSION lightcurves obtained in 2018 simultaneously with TESS. Even if the TTV trend itself does exist in WASP-4, its magnitude and tidal nature are uncertain. Doppler data cannot entirely rule out the Roemer effect induced by possible distant companions.

14. Full orbital solution for the binary system in the northern Galactic disc microlensing event Gaia16aye

Author

Wyrzykowski, Ł., Mróz, P., Rybicki, K. A., Gromadzki, M., Kołaczkowski, Z., Zieliński, M., Zieliński, P., Britavskiy, N., Gomboc, A., Sokolovsky, K., Hodgkin, S. T., Abe, L., Aldi, G. F., AlMannaei, A., Altavilla, G., Al Qasim, A., Anupama, G. C., Awiphan, S., Bachelet, E., Bakış, V., Baker, S., Bartlett, S., Bendjoya, P., Benson, K., Bikmaev, I. F., Birenbaum, G., Blagorodnova, N., Blanco-Cuaresma, S., Boeva, S., Bonanos, A. Z., Bozza, V., Bramich, D. M., Bruni, I., Burenin, R. A., Burgaz, U., Butterley, T., Caines, H. E., Caton, D. B., Calchi Novati, S., Carrasco, J. M., Cassan, A., Čepas, V., Cropper, M., Chruślińska, M., Clementini, G., Clerici, A., Conti, D., Conti, M., Cross, S., Cusano, F., Damljanovic, G., Dapergolas, A., D’Ago, G., de Bruijne, J. H. J., Dennefeld, M., Dhillon, V. S., Dominik, M., Dziedzic, J., Erece, O., Eselevich, M. V., Esenoglu, H., Eyer, L., Figuera Jaimes, R., Fossey, S. J., Galeev, A. I., Grebenev, S. A., Gupta, A. C., Gutaev, A. G., Hallakoun, N., Hamanowicz, A., Han, C., Handzlik, B., Haislip, J. B., Hanlon, L., Hardy, L. K., Harrison, D. L., van Heerden, H. J., Hoette, V. L., Horne, K., Hudec, R., Hundertmark, M., Ihanec, N., Irtuganov, E. N., Itoh, R., Iwanek, P., Jovanovic, M. D., Janulis, R., Jelínek, M., Jensen, E., Kaczmarek, Z., Katz, D., Khamitov, I. M., Kilic, Y., Klencki, J., Kolb, U., Kopacki, G., Kouprianov, V. V., Kruszyńska, K., Kurowski, S., Latev, G., Lee, C.-H., Leonini, S., Leto, G., Lewis, F., Li, Z., Liakos, A., Littlefair, S. P., Lu, J., Manser, C. J., Mao, S., Maoz, D., Martin-Carrillo, A., Marais, J. P., Maskoliūnas, M., Maund, J. R., Meintjes, P. J., Melnikov, S. S., Ment, K., Mikołajczyk, P., Morrell, M., Mowlavi, N., Moździerski, D., Murphy, D., Nazarov, S., Netzel, H., Nesci, R., Ngeow, C.-C., Norton, A. J., Ofek, E. O., Pakštienė, E., Palaversa, L., Pandey, A., Paraskeva, E., Pawlak, M., Penny, M. T., Penprase, B. E., Piascik, A., Prieto, J. L., Qvam, J. K. T., Ranc, C., Rebassa-Mansergas, A., Reichart, D. E., Reig, P., Rhodes, L., Rivet, J.-P., Rixon, G., Roberts, D., Rosi, P., Russell, D. M., Zanmar Sanchez, R., Scarpetta, G., Seabroke, G., Shappee, B. J., Schmidt, R., Shvartzvald, Y., Sitek, M., Skowron, J., Śniegowska, M., Snodgrass, C., Soares, P. S., van Soelen, B., Spetsieri, Z. T., Stankevičiūtė, A., Steele, I. A., Street, R. A., Strobl, J., Strubble, E., Szegedi, H., Tinjaca Ramirez, L. M., Tomasella, L., Tsapras, Y., Vernet, D., Villanueva, S., Vince, O., Wambsganss, J., van der Westhuizen, I. P., Wiersema, K., Wium, D., Wilson, R. W., Yoldas, A., Zhuchkov, R. Ya., Zhukov, D. G., Zdanavičius, J., Zoła, S., Zubareva, A., Wyrzykowski, Ł., Mróz, P., Rybicki, K. A., Gromadzki, M., Kołaczkowski, Z., Zieliński, M., Zieliński, P., Britavskiy, N., Gomboc, A., Sokolovsky, K., Hodgkin, S. T., Abe, L., Aldi, G. F., AlMannaei, A., Altavilla, G., Al Qasim, A., Anupama, G. C., Awiphan, S., Bachelet, E., Bakış, V., Baker, S., Bartlett, S., Bendjoya, P., Benson, K., Bikmaev, I. F., Birenbaum, G., Blagorodnova, N., Blanco-Cuaresma, S., Boeva, S., Bonanos, A. Z., Bozza, V., Bramich, D. M., Bruni, I., Burenin, R. A., Burgaz, U., Butterley, T., Caines, H. E., Caton, D. B., Calchi Novati, S., Carrasco, J. M., Cassan, A., Čepas, V., Cropper, M., Chruślińska, M., Clementini, G., Clerici, A., Conti, D., Conti, M., Cross, S., Cusano, F., Damljanovic, G., Dapergolas, A., D’Ago, G., de Bruijne, J. H. J., Dennefeld, M., Dhillon, V. S., Dominik, M., Dziedzic, J., Erece, O., Eselevich, M. V., Esenoglu, H., Eyer, L., Figuera Jaimes, R., Fossey, S. J., Galeev, A. I., Grebenev, S. A., Gupta, A. C., Gutaev, A. G., Hallakoun, N., Hamanowicz, A., Han, C., Handzlik, B., Haislip, J. B., Hanlon, L., Hardy, L. K., Harrison, D. L., van Heerden, H. J., Hoette, V. L., Horne, K., Hudec, R., Hundertmark, M., Ihanec, N., Irtuganov, E. N., Itoh, R., Iwanek, P., Jovanovic, M. D., Janulis, R., Jelínek, M., Jensen, E., Kaczmarek, Z., Katz, D., Khamitov, I. M., Kilic, Y., Klencki, J., Kolb, U., Kopacki, G., Kouprianov, V. V., Kruszyńska, K., Kurowski, S., Latev, G., Lee, C.-H., Leonini, S., Leto, G., Lewis, F., Li, Z., Liakos, A., Littlefair, S. P., Lu, J., Manser, C. J., Mao, S., Maoz, D., Martin-Carrillo, A., Marais, J. P., Maskoliūnas, M., Maund, J. R., Meintjes, P. J., Melnikov, S. S., Ment, K., Mikołajczyk, P., Morrell, M., Mowlavi, N., Moździerski, D., Murphy, D., Nazarov, S., Netzel, H., Nesci, R., Ngeow, C.-C., Norton, A. J., Ofek, E. O., Pakštienė, E., Palaversa, L., Pandey, A., Paraskeva, E., Pawlak, M., Penny, M. T., Penprase, B. E., Piascik, A., Prieto, J. L., Qvam, J. K. T., Ranc, C., Rebassa-Mansergas, A., Reichart, D. E., Reig, P., Rhodes, L., Rivet, J.-P., Rixon, G., Roberts, D., Rosi, P., Russell, D. M., Zanmar Sanchez, R., Scarpetta, G., Seabroke, G., Shappee, B. J., Schmidt, R., Shvartzvald, Y., Sitek, M., Skowron, J., Śniegowska, M., Snodgrass, C., Soares, P. S., van Soelen, B., Spetsieri, Z. T., Stankevičiūtė, A., Steele, I. A., Street, R. A., Strobl, J., Strubble, E., Szegedi, H., Tinjaca Ramirez, L. M., Tomasella, L., Tsapras, Y., Vernet, D., Villanueva, S., Vince, O., Wambsganss, J., van der Westhuizen, I. P., Wiersema, K., Wium, D., Wilson, R. W., Yoldas, A., Zhuchkov, R. Ya., Zhukov, D. G., Zdanavičius, J., Zoła, S., and Zubareva, A.

Abstract

Gaia16aye was a binary microlensing event discovered in the direction towards the northern Galactic disc and was one of the first microlensing events detected and alerted to by the Gaia space mission. Its light curve exhibited five distinct brightening episodes, reaching up to I = 12 mag, and it was covered in great detail with almost 25 000 data points gathered by a network of telescopes. We present the photometric and spectroscopic follow-up covering 500 days of the event evolution. We employed a full Keplerian binary orbit microlensing model combined with the motion of Earth and Gaia around the Sun to reproduce the complex light curve. The photometric data allowed us to solve the microlensing event entirely and to derive the complete and unique set of orbital parameters of the binary lensing system. We also report on the detection of the first-ever microlensing space-parallax between the Earth and Gaia located at L2. The properties of the binary system were derived from microlensing parameters, and we found that the system is composed of two main-sequence stars with masses 0.57 ± 0.05 M⊙ and 0.36 ± 0.03 M⊙ at 780 pc, with an orbital period of 2.88 years and an eccentricity of 0.30. We also predict the astrometric microlensing signal for this binary lens as it will be seen by Gaia as well as the radial velocity curve for the binary system. Events such as Gaia16aye indicate the potential for the microlensing method of probing the mass function of dark objects, including black holes, in directions other than that of the Galactic bulge. This case also emphasises the importance of long-term time-domain coordinated observations that can be made with a network of heterogeneous telescopes.

15. Homogeneously derived transit timings for 17 exoplanets and reassessed TTV trends for WASP-12 and WASP-4

Author

Baluev, R V, Sokov, E N, Jones, H R A, Shaidulin, V Sh, Sokova, I A, Nielsen, L D, Benni, P, Schneiter, E M, D’Angelo, C Villarreal, Fernández-Lajús, E, Di Sisto, R P, Baştürk, Ö, Bretton, M, Wunsche, A, Hentunen, V-P, Shadick, S, Jongen, Y, Kang, W, Kim, T, Pakštienė, E, Qvam, J K T, Knight, C R, Guerra, P, Marchini, A, Salvaggio, F, Papini, R, Evans, P, Salisbury, M., Garcia, F, Molina, D, Garlitz, J, Esseiva, N, Ogmen, Y, Karavaev, Yu, Rusov, S, Ibrahimov, M A, Karimov, R G, Baluev, R V, Sokov, E N, Jones, H R A, Shaidulin, V Sh, Sokova, I A, Nielsen, L D, Benni, P, Schneiter, E M, D’Angelo, C Villarreal, Fernández-Lajús, E, Di Sisto, R P, Baştürk, Ö, Bretton, M, Wunsche, A, Hentunen, V-P, Shadick, S, Jongen, Y, Kang, W, Kim, T, Pakštienė, E, Qvam, J K T, Knight, C R, Guerra, P, Marchini, A, Salvaggio, F, Papini, R, Evans, P, Salisbury, M., Garcia, F, Molina, D, Garlitz, J, Esseiva, N, Ogmen, Y, Karavaev, Yu, Rusov, S, Ibrahimov, M A, and Karimov, R G

Abstract

We homogeneously analyse ∼3.2 × 105 photometric measurements for ∼1100 transit lightcurves belonging to 17 exoplanet hosts. The photometric data cover 16 years 2004–2019 and include amateur and professional observations. Old archival lightcurves were reprocessed using up-to-date exoplanetary parameters and empirically debiased limb-darkening models. We also derive self-consistent transit and radial-velocity fits for 13 targets. We confirm the nonlinear TTV trend in the WASP-12 data at a high significance, and with a consistent magnitude. However, Doppler data reveal hints of a radial acceleration about ( − 7.5 ± 2.2) m/s/yr, indicating the presence of unseen distant companions, and suggesting that roughly 10 per cent of the observed TTV was induced via the light-travel (or Roemer) effect. For WASP-4, a similar TTV trend suspected after the recent TESS observations appears controversial and model-dependent. It is not supported by our homogeneus TTV sample, including 10 ground-based EXPANSION lightcurves obtained in 2018 simultaneously with TESS. Even if the TTV trend itself does exist in WASP-4, its magnitude and tidal nature are uncertain. Doppler data cannot entirely rule out the Roemer effect induced by possible distant companions.

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