@article{1e4e63bb83944ad88fafe97075c45012,
title = "TESS Hunt for Young and Maturing Exoplanets (THYME). VI. An 11 Myr Giant Planet Transiting a Very-low-mass Star in Lower Centaurus Crux",
abstract = "Mature super-Earths and sub-Neptunes are predicted to be ≃ Jovian radius when younger than 10 Myr. Thus, we expect to find 5-15 R planets around young stars even if their older counterparts harbor none. We report the discovery and validation of TOI 1227b, a 0.85 ± 0.05 R J (9.5 R) planet transiting a very-low-mass star (0.170 ± 0.015 M) every 27.4 days. TOI 1227's kinematics and strong lithium absorption confirm that it is a member of a previously discovered subgroup in the Lower Centaurus Crux OB association, which we designate the Musca group. We derive an age of 11 ± 2 Myr for Musca, based on lithium, rotation, and the color-magnitude diagram of Musca members. The TESS data and ground-based follow-up show a deep (2.5%) transit. We use multiwavelength transit observations and radial velocities from the IGRINS spectrograph to validate the signal as planetary in nature, and we obtain an upper limit on the planet mass of ≃0.5 M J. Because such large planets are exceptionally rare around mature low-mass stars, we suggest that TOI 1227b is still contracting and will eventually turn into one of the more common <5 R planets.",
author = "Mann, {Andrew W.} and Wood, {MacKenna L.} and Schmidt, {Stephen P.} and Barber, {Madyson G.} and Owen, {James E.} and Tofflemire, {Benjamin M.} and Newton, {Elisabeth R.} and Mamajek, {Eric E.} and Bush, {Jonathan L.} and Mace, {Gregory N.} and Kraus, {Adam L.} and Thao, {Pa Chia} and Andrew Vanderburg and Joe Llama and Johns-Krull, {Christopher M.} and L. Prato and Stahl, {Asa G.} and Tang, {Shih Yun} and Fields, {Matthew J.} and Collins, {Karen A.} and Collins, {Kevin I.} and Tianjun Gan and Jensen, {Eric L.N.} and Jacob Kamler and Schwarz, {Richard P.} and Elise Furlan and Gnilka, {Crystal L.} and Howell, {Steve B.} and Lester, {Kathryn V.} and Owens, {Dylan A.} and Olga Suarez and Djamel Mekarnia and Tristan Guillot and Lyu Abe and Triaud, {Amaury H.M.J.} and Johnson, {Marshall C.} and Milburn, {Reilly P.} and Rizzuto, {Aaron C.} and Quinn, {Samuel N.} and Ronan Kerr and Ricker, {George R.} and Roland Vanderspek and Latham, {David W.} and Sara Seager and Winn, {Joshua N.} and Jenkins, {Jon M.} and Guerrero, {Natalia M.} and Avi Shporer and Schlieder, {Joshua E.} and Brian McLean and Bill Wohler",
note = "Publisher Copyright: {\textcopyright} 2022. The American Astronomical Society. All rights reserved.",
year = "2022",
month = apr,
day = "1",
doi = "10.3847/1538-3881/ac511d",
language = "English (US)",
volume = "163",
journal = "Astronomical Journal",
issn = "0004-6256",
publisher = "IOP Publishing Ltd.",
number = "4",
}