Extrasolar Planets

A Second Earth-Sized Planet in the Habitable Zone of the M Dwarf, TOI-700

By Keith Cowing
Status Report
astro-ph.EP
January 16, 2023
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A Second Earth-Sized Planet in the Habitable Zone of the M Dwarf, TOI-700
TOI-700 e (pink) resides in the Optimistic Habitable Zone (light green) around its host star in between the orbits of TOI-700 c and d. — astro-ph.EP

We report the discovery of TOI-700 e, a 0.95 R⊕ planet residing in the Optimistic Habitable Zone (HZ) of its host star.

The Conservative Habitable Zone is shown in dark green, and planets b, c, and d (from inner to outer) are shown in indigo.

We report the discovery of TOI-700 e, a 0.95 R⊕ planet residing in the Optimistic Habitable Zone (HZ) of its host star.

This discovery was enabled by multiple years of monitoring from NASA’s Transiting Exoplanet Survey Satellite (TESS) mission. The host star, TOI-700 (TIC 150428135), is a nearby (31.1 pc), inactive, M2.5 dwarf (Vmag=13.15). TOI-700 is already known to host three planets, including the small, HZ planet, TOI-700 d. The new planet has an orbital period of 27.8 days and, based on its radius (0.95 R⊕), it is likely rocky. TOI-700 was observed for 21 sectors over Years 1 and 3 of the TESS mission, including 10 sectors at 20-second cadence in Year 3.

Using this full set of TESS data and additional follow-up observations, we identify, validate, and characterize TOI-700 e. This discovery adds another world to the short list of small, HZ planets transiting nearby and bright host stars. Such systems, where the stars are bright enough that follow-up observations are possible to constrain planet masses and atmospheres using current and future facilities, are incredibly valuable. The presence of multiple small, HZ planets makes this system even more enticing for follow-up observations.

Emily A. Gilbert, Andrew Vanderburg, Joseph E. Rodriguez, Benjamin J. Hord, Matthew S. Clement, Thomas Barclay, Elisa V. Quintana, Joshua E. Schlieder, Stephen R. Kane, Jon M. Jenkins, Joseph D. Twicken, Michelle Kunimoto, Roland Vanderspek, Giada N. Arney, David Charbonneau, Maximilian N. Günther, Chelsea X. Huang, Giovanni Isopi, Veselin B. Kostov, Martti H. Kristiansen, David W. Latham, Franco Mallia, Eric E. Mamajek, Ismael Mireles, Samuel N. Quinn, George R. Ricker, Jack Schulte, S. Seager, Gabrielle Suissa, Joshua N. Winn, Allison Youngblood, Aldo Zapparata

Comments: 16 pages, 4 figures, 2 tables, accepted for publication in ApJL
Subjects: Earth and Planetary Astrophysics (astro-ph.EP)
Cite as: arXiv:2301.03617 [astro-ph.EP] (or arXiv:2301.03617v1 [astro-ph.EP] for this version)
https://doi.org/10.48550/arXiv.2301.03617
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Submission history
From: Emily Gilbert
[v1] Mon, 9 Jan 2023 19:00:04 UTC (3,287 KB)
https://arxiv.org/abs/2301.03617
Astrobiology, Astrochemistry

SpaceRef co-founder, Explorers Club Fellow, ex-NASA, Away Teams, Journalist, Space & Astrobiology, Lapsed climber.