A Super-Earth and Sub-Neptune Transiting the Late-type M Dwarf LP 791-18

Crossfield, Ian J. M. and Waalkes, William and Newton, Elisabeth R. and Narita, Norio and Muirhead, Philip and Ment, Kristo and Matthews, Elisabeth and Kraus, Adam and Kostov, Veselin and Kosiarek, Molly R. and Kane, Stephen R. and Isaacson, Howard and Halverson, Sam and Gonzales, Erica and Everett, Mark and Dragomir, Diana and Collins, Karen A. and Chontos, Ashley and Berardo, David and Winters, Jennifer G. and Winn, Joshua N. and Scott, Nicholas J. and Rojas-Ayala, Barbara and Rizzuto, Aaron C. and Petigura, Erik A. and Peterson, Merrin and Mocnik, Teo and Mikal-Evans, Thomas and Mehrle, Nicholas and Matson, Rachel and Kuzuhara, Masayuki and Irwin, Jonathan and Huber, Daniel and Huang, Chelsea ORCID: https://orcid.org/0000-0003-0918-7484 and Howell, Steve and Howard, Andrew W. and Hirano, Teruyuki and Fulton, Benjamin J. and Dupuy, Trent and Dressing, Courtney D. and Dalba, Paul A. and Charbonneau, David and Burt, Jennifer and Berta-Thompson, Zachory and Benneke, Bjorn and Watanabe, Noriharu and Twicken, Joseph D. and Tamura, Motohide and Schlieder, Joshua and Seager, S. and Rose, Mark E. and Ricker, George and Quintana, Elisa and Lepine, Sebastien and Latham, David W. and Kotani, Takayuki and Jenkins, Jon M. and Hori, Yasunori and Colon, Knicole and Caldwell, Douglas A. (2019) A Super-Earth and Sub-Neptune Transiting the Late-type M Dwarf LP 791-18. The Astrophysical Journal Letters, 883 (1):L16. pp. 1-13. ISSN 2041-8205

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Abstract

Planets occur most frequently around cool dwarfs, but only a handful of specific examples are known to orbit the latest-type M stars. Using TESS photometry, we report the discovery of two planets transiting the low-mass star called LP 791-18 (identified by TESS as TOI 736). This star has spectral type M6V, effective temperature 2960 K, and radius 0.17 R o, making it the third-coolest star known to host planets. The two planets straddle the radius gap seen for smaller exoplanets; they include a 1.1R ⊕ planet on a 0.95 day orbit and a 2.3R ⊕ planet on a 5 day orbit. Because the host star is small the decrease in light during these planets' transits is fairly large (0.4% and 1.7%). This has allowed us to detect both planets' transits from ground-based photometry, refining their radii and orbital ephemerides. In the future, radial velocity observations and transmission spectroscopy can both probe these planets' bulk interior and atmospheric compositions, and additional photometric monitoring would be sensitive to even smaller transiting planets.


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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: 31 Mar 2022 03:57
Last Modified: 17 May 2022 01:59
Uncontrolled Keywords: Exoplanet astronomy; Exoplanet systems; High resolution spectroscopy; Low mass stars; Transit photometry; 486; 484; 2096; 2050; 1709; Astrophysics - Earth and Planetary Astrophysics
Fields of Research (2020): 51 PHYSICAL SCIENCES > 5101 Astronomical sciences > 510109 Stellar astronomy and planetary systems
Identification Number or DOI: https://doi.org/10.3847/2041-8213/ab3d30
URI: http://eprints.usq.edu.au/id/eprint/47429

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