_version_ 1866929437280305152
author Tey, Evan
Shporer, Avi
Lin, Zifan
Stassun, Keivan G.
Lissauer, Jack J.
Hellier, Coel
Collins, Karen A.
Collins, Kevin I.
Wingham, Geof
Relles, Howard M.
Mallia, Franco
Isopi, Giovanni
Kielkopf, John F.
Conti, Dennis M.
Schwarz, Richard P.
Zapparata, Aldo
Giacalone, Steven
Furlan, Elise
Hartman, Zachary D.
Howell, Steve B.
Scott, Nicholas J.
Ziegler, Carl
Briceno, Cesar
Law, Nicholas
Mann, Andrew W.
Charbonneau, David
Essack, Zahra
Striegel, Stephanie
Ricker, George R.
Vanderspek, Roland
Seager, Sara
Winn, Joshua N.
Jenkins, Jon M.
author_facet Tey, Evan
Shporer, Avi
Lin, Zifan
Stassun, Keivan G.
Lissauer, Jack J.
Hellier, Coel
Collins, Karen A.
Collins, Kevin I.
Wingham, Geof
Relles, Howard M.
Mallia, Franco
Isopi, Giovanni
Kielkopf, John F.
Conti, Dennis M.
Schwarz, Richard P.
Zapparata, Aldo
Giacalone, Steven
Furlan, Elise
Hartman, Zachary D.
Howell, Steve B.
Scott, Nicholas J.
Ziegler, Carl
Briceno, Cesar
Law, Nicholas
Mann, Andrew W.
Charbonneau, David
Essack, Zahra
Striegel, Stephanie
Ricker, George R.
Vanderspek, Roland
Seager, Sara
Winn, Joshua N.
Jenkins, Jon M.
contents We report the discovery of the transiting planet GJ 238 b, with a radius of $0.566\pm0.014$ R$_{\oplus}$ ($1.064\pm0.026$ times the radius of Mars) and an orbital period of 1.74 day. The transit signal was detected by the TESS mission and designated TOI-486.01. The star's position close to the Southern ecliptic pole allows for almost continuous observations by TESS when it is observing the Southern sky. The host star is an M2.5 dwarf with $V=11.57\pm0.02$ mag, $K=7.030\pm0.023$ mag, a distance of $15.2156\pm0.0030$ pc, a mass of $0.4193_{-0.0098}^{+0.0095}$ M$_{\odot}$, a radius of $0.4314_{-0.0071}^{+0.0075}$ R$_{\odot}$, and an effective temperature of $3{,}485\pm140$ K. We validate the planet candidate by ruling out or rendering highly unlikely each of the false positive scenarios, based on archival data and ground-based follow-up observations. Validation was facilitated by the host star's small size and high proper motion, of $892.633\pm0.025$ mas yr$^{-1}$.
format Preprint
id arxiv_https___arxiv_org_abs_2407_18199
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle GJ 238 b: A 0.57 Earth Radius Planet Orbiting an M2.5 Dwarf Star at 15.2 pc
Tey, Evan
Shporer, Avi
Lin, Zifan
Stassun, Keivan G.
Lissauer, Jack J.
Hellier, Coel
Collins, Karen A.
Collins, Kevin I.
Wingham, Geof
Relles, Howard M.
Mallia, Franco
Isopi, Giovanni
Kielkopf, John F.
Conti, Dennis M.
Schwarz, Richard P.
Zapparata, Aldo
Giacalone, Steven
Furlan, Elise
Hartman, Zachary D.
Howell, Steve B.
Scott, Nicholas J.
Ziegler, Carl
Briceno, Cesar
Law, Nicholas
Mann, Andrew W.
Charbonneau, David
Essack, Zahra
Striegel, Stephanie
Ricker, George R.
Vanderspek, Roland
Seager, Sara
Winn, Joshua N.
Jenkins, Jon M.
Earth and Planetary Astrophysics
We report the discovery of the transiting planet GJ 238 b, with a radius of $0.566\pm0.014$ R$_{\oplus}$ ($1.064\pm0.026$ times the radius of Mars) and an orbital period of 1.74 day. The transit signal was detected by the TESS mission and designated TOI-486.01. The star's position close to the Southern ecliptic pole allows for almost continuous observations by TESS when it is observing the Southern sky. The host star is an M2.5 dwarf with $V=11.57\pm0.02$ mag, $K=7.030\pm0.023$ mag, a distance of $15.2156\pm0.0030$ pc, a mass of $0.4193_{-0.0098}^{+0.0095}$ M$_{\odot}$, a radius of $0.4314_{-0.0071}^{+0.0075}$ R$_{\odot}$, and an effective temperature of $3{,}485\pm140$ K. We validate the planet candidate by ruling out or rendering highly unlikely each of the false positive scenarios, based on archival data and ground-based follow-up observations. Validation was facilitated by the host star's small size and high proper motion, of $892.633\pm0.025$ mas yr$^{-1}$.
title GJ 238 b: A 0.57 Earth Radius Planet Orbiting an M2.5 Dwarf Star at 15.2 pc
topic Earth and Planetary Astrophysics
url https://arxiv.org/abs/2407.18199