MuSCAT2 multicolour validation of TESS candidates: an ultra-short-period substellar object around an M dwarf
H. Parviainen, E. Palle, M. R. Zapatero-Osorio, P. Montanes Rodriguez, F. Murgas, N. Narita, D. Hidalgo Soto, V. J. S. Béjar, J. Korth, M. Monelli, N. Casasayas… 展开作者
H. Parviainen, E. Palle, M. R. Zapatero-Osorio, P. Montanes Rodriguez, F. Murgas, N. Narita, D. Hidalgo Soto, V. J. S. Béjar, J. Korth, M. Monelli, N. Casasayas Barris, N. Crouzet, J. P. de Leon, A. Fukui, A. Hernandez, P. Klagyivik, N. Kusakabe, R. Luque, M. Mori, T. Nishiumi, J. Prieto-Arranz, M. Tamura, N. Watanabe, C. Burke, D. Charbonneau, K. A. Collins, K. I. Collins, D. Conti, A. Garcia Soto, J. S. Jenkins, J. M. Jenkins, A. Levine, J. Li, S. Rinehart, S. Seager, P. Tenenbaum, E. B. Ting, R. Vanderspek, M. Vezie, J. N Winn
We report the discovery of TOI 263.01 (TIC 120916706), a transiting substellar object (R = 0.87 RJup) orbiting a faint M3.5~V dwarf (V=18.97) on a 0.56~d orbit. We set out to determine the nature of the TESS planet candidate TOI 263.01 using ground-based multicolour transit photometry. The host star is faint, which makes RV confirmation challenging, but the large transit depth makes the candidate suitable for validation through multicolour photometry. Our analysis combines three transits observed simultaneously in r', i', and z_s bands using the MuSCAT2 multicolour imager, three LCOGT-observed transit light curves in g, r', and i' bands, a TESS light curve from Sector 3, and a low-resolution spectrum for stellar characterisation observed with the ALFOSC spectrograph. We model the light curves with PyTransit using a transit model that includes a physics-based light contamination component that allows us to estimate the contamination from unresolved sources from the multicolour photometry. This allows us to derive the true planet-star radius ratio marginalised over the contamination allowed by the photometry, and, combined with the stellar radius, gives us a reliable estimate of the object's absolute radius. The ground-based photometry excludes contamination from unresolved sources with a significant colour difference to TOI 263. Further, contamination from sources of same stellar type as the host is constrained to levels where the true radius ratio posterior has a median of 0.217. The median radius ratio corresponds to an absolute planet radius of 0.87 RJup, which confirms the substellar nature of the planet candidate. The object is either a giant planet or a brown dwarf (BD) located deep inside the so-called "brown dwarf desert". Both possibilities offer a challenge to current planet/BD formation models and makes 263.01 an object deserving of in-depth follow-up studies.
A Previously Underexplored Regime in TESS: Minute-Scale Eclipses Reveal Ten White Dwarf-Cool M-Dwarf Binaries
Massachusetts Institute of Technology（麻省理工学院）；Institut Supérieur de l’Aéronautique et de l’Espace (ISAE-SUPAERO)（法国高等航空航天学院）；University of Birmingham（伯明翰大学）；Université de Liège（列日大学）；Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology（麻省理工学院卡弗里天体物理与空间研究研究所）；University of Florida（佛罗里达大学）；Instituto de Astrofísica de Canarias (IAC)（加那利天体物理学研究所）
The Montreal Open Clusters and Associations (MOCA) Database: A Census of Nearby Associations, Open Clusters, and Young Substellar Objects within 500 pc of the Sun
Planétarium de Montréal, Espace pour la Vie（蒙特利尔天文馆，生命空间）；Trottier Institute for Research on Exoplanets, Université de Montréal（特罗蒂尔系外行星研究所，蒙特利尔大学）；Department of Astrophysics, American Museum of Natural History（天体物理系，美国自然历史博物馆）；Department of Astronomy, Columbia University（天文学系，哥伦比亚大学）；School of Physical Sciences, The Open University（物理科学学院，开放大学）
TOI-6884b: A low-mass brown dwarf transiting a slightly evolved star
Universidad Nacional Autónoma de México（墨西哥国立自治大学）；Instituto de Astronomía（天文学研究所）；Astronomy & Astrophysics Division, Physical Research Laboratory（物理研究实验室天文与天体物理部）；Indian Institute of Techonology（印度理工学院）；Center for Astrophysics | Harvard & Smithsonian（哈佛史密森天体物理中心）；Instituto de Astrofísica de Canarias (IAC)（加那利群岛天体物理研究所）
Hidden worlds: A non-transiting candidate planet in the Neptunian desert around the solar-type pulsator KIC 9139163
INAF – Osservatorio Astrofisico di Catania（意大利国家天体物理研究所卡塔尼亚天文台）；Space Telescope Science Institute（太空望远镜科学研究所）；Instituto de Astrofísica de Canarias (IAC)（加那利群岛天体物理研究所）；Departamento de Astrofísica, Universidad de la Laguna（拉帕尔马大学天体物理学系）；Space Research Institute, Austrian Academy of Sciences（奥地利科学院空间研究所）；Université Paris-Saclay, Université Paris Cité, CEA, CNRS, AIM（巴黎萨克雷大学、巴黎西岱大学、法国原子能和替代能源委员会、法国国家科学研究中心、天体分子基础研究实验室）
TOI-2155 b: A Massive Brown Dwarf or a Very Low-Mass Star?
Sydney Institute for Astronomy, School of Physics, University of Sydney（悉尼大学物理学院天体物理学研究所）；Department of Physics and McDonnell Center for the Space Sciences, Washington University（华盛顿大学物理系与麦克唐纳太空科学中心）；Institute for Astronomy, University of Hawaii at Manoa（夏威夷大学马诺阿分校天文研究所）；School of Physics and Astronomy, University of Leicester（莱斯特大学物理与天文学学院）；Macquarie University Research Fellow (MQRF)（麦考瑞大学研究研究员（MQRF））；Australian Astronomical Optics, Macquarie University（麦考瑞大学澳大利亚天文光学）；Astrophysics and Space Technologies Research Centre, Macquarie University（麦考瑞大学天体物理学与空间技术中心）
