Exoplanetology: Exoplanets & Exomoons

Demographics Of M Dwarf Binary Exoplanet Hosts Discovered by TESS

By Keith Cowing
Status Report
astro-ph.EP
December 12, 2024
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Demographics Of M Dwarf Binary Exoplanet Hosts Discovered by TESS
H-R Diagram of TESS TOI candidates. Grey symbols are randomly chosen F, G, K stars taken from the TOI list and plotted here to give a perspective for their locations in an H-R Diagram. Red dots are M star TOIs which have already been deemed to be false positives, while blue dots show the location of the remaining M star TOI candidates. The blue dots above the main sequence are deemed to be giants and are removed from any subsequent analysis. — astro-ph.EP

M dwarfs have become increasingly important in the detection of exoplanets and the study of Earth-sized planets and their habitability. However, 20-30% of M dwarfs have companions that can impact the formation and evolution of planetary systems.

We use high-resolution imaging and Gaia astrometry to detect stellar companions around M dwarf exoplanet hosts discovered by TESS and determine the projected separation and estimated stellar masses for each system.

We find 47 companions around 216 M dwarfs and a multiplicity rate of 19.4±2.7% that is consistent with field M dwarfs. The binary projected separation distribution is shifted to larger separations, confirming the lack of close binaries hosting transiting exoplanets seen in previous studies.

We correct the radii of planets with nearby companions and examine the properties of planets in M dwarf multi-star systems. We also note three multi-planet systems that occur in close binaries (≲50 au) where planet formation is expected to be suppressed.

Rachel A. Matson, Rebecca Gore, Steve B. Howell, David R. Ciardi, Jessie L. Christiansen, Catherine A. Clark, Ian J. M. Crossfield, Sergio B. Fajardo-Acosta, Rachel B. Fernandes, Elise Furlan, Emily A. Gilbert, Erica Gonzales, Kathryn V. Lester, Michael B. Lund, Elisabeth C. Matthews, Alex S. Polanski, Joshua E. Schlieder, Carl Ziegler

Comments: 28 pages, 13 figures, 5 tables, accepted for publication in The Astronomical Journal
Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Solar and Stellar Astrophysics (astro-ph.SR)
Cite as: arXiv:2412.08465 [astro-ph.EP] (or arXiv:2412.08465v1 [astro-ph.EP] for this version)
https://doi.org/10.48550/arXiv.2412.08465
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Submission history
From: Rachel Matson
[v1] Wed, 11 Dec 2024 15:32:01 UTC (506 KB)
https://arxiv.org/abs/2412.08465
Astrobiology,

Keith Cowing

Explorers Club Fellow, ex-NASA Space Station Payload manager/space biologist, Away Teams, Journalist, Lapsed climber, Synaesthete, Na’Vi-Jedi-Freman-Buddhist-mix, ASL, Devon Island and Everest Base Camp veteran, (he/him) 🖖🏻

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