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arXiv · 1903.06107

A super-Earth and two sub-Neptunes transiting the nearby and quiet M dwarf TOI-270

Maximilian N. Günther·Francisco J. Pozuelos·Jason A. Dittmann·Diana Dragomir·Stephen R. Kane·Tansu Daylan·Adina D. Feinstein·Chelsea Huang·Timothy D. Morton·Andrea Bonfanti·L. G. Bouma·Jennifer Burt·Karen A. Collins·Jack J. Lissauer·Elisabeth Matthews·Benjamin T. Montet·Andrew Vanderburg·Songhu Wang·Jennifer G. Winters·George R. Ricker·Roland K. Vanderspek·David W. Latham·Sara Seager·Joshua N. Winn·Jon M. Jenkins·James D. Armstrong·Khalid Barakoui·Natalie Batalha·Jacob L. Bean·Douglas A. Caldwell·David R. Ciardi·Kevin I. Collins·Ian Crossfield·Michael Fausnaugh·Gabor Furesz·Tianjun Gan·Michaël Gillon·Natalia Guerrero·Keith Horne·Steve B. Howell·Michael Ireland·Giovanni Isopi·Emmanuël Jehin·John F. Kielkopf·Sebastien Lepine·Franco Mallia·Rachel A. Matson·Gordon Myers·Enric Palle·Samuel N. Quinn·Howard M. Relles·Bárbara Rojas-Ayala·Joshua Schlieder·Ramotholo Sefako·Avi Shporer·Juan C. Suárez·Thiam-Guan Tan·Eric B. Ting·Joseph D. Twicken·Ian A. Waite
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Abstract

We report the Transiting Exoplanet Survey Satellite discovery of three small planets transiting one of the nearest and brightest M dwarf hosts to date, TOI-270 (TIC 259377017; K-mag 8.3; 22.5 parsec). The M3V-type star is transited by the super-Earth-sized TOI-270 b (1.247+0.089-0.083 R_earth) and the sub-Neptune-sized exoplanets TOI-270 c (2.42+-0.13 R_earth) and TOI-270 d (2.13+-0.12 R_earth). The planets orbit close to a mean-motion resonant chain, with periods (3.36, 5.66, and 11.38 days) near ratios of small integers (5:3 and 2:1). TOI-270 is a prime target for future studies since: 1) its near-resonance allows detecting transit timing variations for precise mass measurements and dynamical studies; 2) its brightness enables independent radial velocity mass measurements; 3) the outer planets are ideal for atmospheric characterisation via transmission spectroscopy; and 4) the quiet star enables future searches for habitable zone planets. Altogether, very few systems with small, temperate exoplanets are as suitable for such complementary and detailed characterisation as TOI-270.

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Maximilian N. Günther, Francisco J. Pozuelos, Jason A. Dittmann, Diana Dragomir, Stephen R. Kane, Tansu Daylan, Adina D. Feinstein, Chelsea Huang, Timothy D. Morton, Andrea Bonfanti, L. G. Bouma, Jennifer Burt, Karen A. Collins, Jack J. Lissauer, Elisabeth Matthews, Benjamin T. Montet, Andrew Vanderburg, Songhu Wang, Jennifer G. Winters, George R. Ricker, Roland K. Vanderspek, David W. Latham, Sara Seager, Joshua N. Winn, Jon M. Jenkins, James D. Armstrong, Khalid Barakoui, Natalie Batalha, Jacob L. Bean, Douglas A. Caldwell, David R. Ciardi, Kevin I. Collins, Ian Crossfield, Michael Fausnaugh, Gabor Furesz, Tianjun Gan, Michaël Gillon, Natalia Guerrero, Keith Horne, Steve B. Howell, Michael Ireland, Giovanni Isopi, Emmanuël Jehin, John F. Kielkopf, Sebastien Lepine, Franco Mallia, Rachel A. Matson, Gordon Myers, Enric Palle, Samuel N. Quinn, Howard M. Relles, Bárbara Rojas-Ayala, Joshua Schlieder, Ramotholo Sefako, Avi Shporer, Juan C. Suárez, Thiam-Guan Tan, Eric B. Ting, Joseph D. Twicken, Ian A. Waite. 2019-03-14. A super-Earth and two sub-Neptunes transiting the nearby and quiet M dwarf TOI-270. https://doi.org/10.1038/s41550-019-0845-5

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