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

Gunther, Maximilian N. and Pozuelos, Francisco J. and Dittmann, Jason A. and Dragomir, Diana and Kane, Stephen R. and Daylan, Tansu and Feinstein, Adina D. and Huang, Chelsea X. and Morton, Timothy D. and Bonfanti, Andrea and Bouma, L. G. and Burt, Jennifer and Collins, Karen A. and Lissauer, Jack J. and Matthews, Elisabeth and Montet, Benjamin T. and Vanderburg, Andrew and Wang, Songhu and Winters, Jennifer G. and Ricker, George R. and Vanderspek, Roland K. and Lathem, David W. and Seager, Sara and Winn, Joshua N. and Jenkins, Jon M. and Armstrong, James D. and Barkaoui, Khalid and Batalha, Natalie and Bean, Jacob L. and Caldwell, Douglas A. and Ciardi, David R. and Collins, Kevin I. and Crossfield, Ian and Fausnaugh, Michael and Furesz, Gabor and Gan, Tianjun and Gillon, Michael and Guerrero, Natalia and Horne, Keith and Howell, Steve B. and Ireland, Michael and Isopi, Giovanni and Jehin, Emmanuel and Kielkopf, John F. and Lepine, Sebastien and Mallia, Franco and Matson, Rachel A. and Myers, Gordon and Palle, Enric and Quinn, Samuel N. and Relles, Howard M. and Rojas-Ayala, Barbara and Schlieder, Joshua and Sefako, Ramotholo and Shporer, Avi and Suarez, Juan C. and Tan, Thiam-Guan and Ting, Eric B. and Twicken, Joesph D. and Waite, Ian A. (2019) A super-Earth and two sub-Neptunes transiting the nearby and quiet M dwarf TOI-270. Nature Astronomy, 3 (12). pp. 1099-1108.

Abstract

One of the primary goals of exoplanetary science is to detect small, temperate planets passing (transiting) in front of bright and quiet host stars. This enables the characterization of planetary sizes, orbits, bulk compositions, atmospheres and formation histories. These studies are facilitated by small and cool M dwarf host stars. Here we report the Transiting Exoplanet Survey Satellite (TESS)1 discovery of three small planets transiting one of the nearest and brightest M dwarf hosts observed to date, TOI-270 (TIC 259377017, with K-magnitude 8.3, and 22.5 parsecs away from Earth). The M3V-type star is transited by the super-Earth-sized planet TOI-270 b (1.247 +0.089 −0.083 R⊕) and the sub-Neptune-sized planets TOI-270 c (2.42 ± 0.13 R⊕) and TOI-270 d (2.13 ± 0.12 R⊕). The planets orbit close to a mean-motion resonant chain, with periods (3.36 days, 5.66 days and 11.38 days, respectively) near ratios of small integers (5:3 and 2:1). TOI-270 is a prime target for future studies because (1) its near-resonance allows the detection of transit timing variations, enabling precise mass measurements and dynamical studies; (2) its brightness enables independent radial-velocity mass measurements; (3) the outer planets are ideal for atmospheric characterization via transmission spectroscopy; and (4) the quietness of the star enables future searches for habitable zone planets. Altogether, very few systems with small, temperate exoplanets are as suitable for such complementary and detailed characterization as TOI-270.


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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Faculty/School / Institute/Centre: Current - Institute for Advanced Engineering and Space Sciences - Centre for Astrophysics (1 Aug 2018 -)
Faculty/School / Institute/Centre: Current - Institute for Advanced Engineering and Space Sciences - Centre for Astrophysics (1 Aug 2018 -)
Date Deposited: 30 Jan 2020 03:22
Last Modified: 30 Jan 2020 03:41
Uncontrolled Keywords: dwarf host stars; Transiting Exoplanet Survey Satellite; TOI-270
Fields of Research : 02 Physical Sciences > 0201 Astronomical and Space Sciences > 020110 Stellar Astronomy and Planetary Systems
Identification Number or DOI: 10.1038/s41550-019-0845-5
URI: http://eprints.usq.edu.au/id/eprint/37666

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