A Pair of TESS Planets Spanning the Radius Valley around the Nearby Mid-M Dwarf LTT 3780

• Type: Article in International Scientific Journal
• Date: 2020

Authors

Mayor, M (Author) Other; Matson, RA (Author) Other; Fiorenzano, AFM (Author) Other; Mann, AW (Author) Other; Magazzu, A (Author) Other; Lovis, C (Author) Other; Lopez Morales, M (Author) Other; Lopez, E (Author) Other; Lissauer, JJ (Author) Other; Lepine, S (Author) Other; Law, N (Author) Other; Kielkopf, JF (Author) Other; Johnson, JA (Author) Other; Jensen, ELN (Author) Other; Howell, SB (Author) Other; Gonzales, E (Author) Other; Ghedina, A (Author) Other; Forveille, T (Author) Other; Figueira, P (Author) Other; Dumusque, X (Author) Other; Dressing, CD (Author) Other; Doyon, R (Author) Other; Diaz, RF (Author) Other; Di Fabrizio, L (Author) Other; Delfosse, X (Author) Other; Cosentino, R (Author) Other; Conti, DM (Author) Other; Collins, KI (Author) Other; Cameron, AC (Author) Other; Ciardi, D (Author) Other; Caldwell, DA (Author) Other; Burke, C (Author) Other; Buchhave, L (Author) Other; Briceno, C (Author) Other; Boyd, P (Author) Other; Bouchy, F (Author) Other; Beichman, C (Author) Other; Artigau, E (Author) Other; Almenara, JM (Author) Other; Cloutier, R (Author) Other; Eastman, JD (Author) Other; Rodriguez, JE (Author) Other; Astudillo Defru, N (Author) Other; Bonfils, X (Author) Other; Mortier, A (Author) Other; Watson, CA (Author) Other; Stalport, M (Author) Other; Pinamonti, M (Author) Other; Lienhard, F (Author) Other; Harutyunyan, A (Author) Other; Damasso, M (Author) Other; Latham, DW (Author) Other; Collins, KA (Author) Other; Massey, R (Author) Other; Irwin, J (Author) Other; Winters, JG (Author) Other; Charbonneau, D (Author) Other; Ziegler, C (Author) Other; Matthews, E (Author) Other; Crossfield, IJM (Author) Other; Kreidberg, L (Author) Other; Quinn, SN (Author) Other; Ricker, G (Author) Other; Vanderspek, R (Author) Other; Seager, S (Author) Other; Winn, J (Author) Other; Jenkins, JM (Author) Other; Vezie, M (Author) Other; Udry, S (Author) Other; Twicken, JD (Author) Other; Tenenbaum, P (Author) Other; Sozzetti, A (Author) Other; Segransan, D (Author) Other; Schlieder, JE (Author) Other; Sasselov, D (Author) Other; N.C. Santos (Author) FCUP; Rice, K (Author) Other; Rackham, BV (Author) Other; Poretti, E (Author) Other; Piotto, G (Author) Other; Phillips, D (Author) Other; Pepe, F (Author) Other; Molinari, E (Author) Other; Mignon, L (Author) Other; Micela, G (Author) Other; Melo, C (Author) Other; de Medeiros, JR (Author) Other

Journal

Title: Astronomical Journal

Vol. 160

Final page: 3

ISSN: 0004-6256

Publisher: American Astronomical Society

Indexing

ISI Web of Knowledge - 50 Citations

Scopus - 53 Citations

Other information

Authenticus ID: P-00S-B6B

DOI: 10.3847/1538-3881/ab91c2

Abstract (EN): We present the confirmation of two new planets transiting the nearby mid-M dwarf LTT 3780 (TIC 36724087, TOI-732, V = 13.07, K-s = 8.204, R-s = 0.374 R<sub, M-s = 0.401 M-circle dot, d = 22 pc). The two planet candidates are identified in a single Transiting Exoplanet Survey Satellite sector and validated with reconnaissance spectroscopy, ground-based photometric follow-up, and high-resolution imaging. With measured orbital periods of P-b = 0.77, P-c = 12.25 days and sizes r(p,b) = 1.33 0.07, r(p,c) = 2.30 0.16 R-circle plus, the two planets span the radius valley in period-radius space around low-mass stars, thus making the system a laboratory to test competing theories of the emergence of the radius valley in that stellar mass regime. By combining 63 precise radial velocity measurements from the High Accuracy Radial velocity Planet Searcher (HARPS) and HARPS-N, we measure planet masses of M-circle plus, which indicates that LTT 3780b has a bulk composition consistent with being Earth-like, while LTT 3780c likely hosts an extended H/He envelope. We show that the recovered planetary masses are consistent with predictions from both photoevaporation and core-powered mass-loss models. The brightness and small size of LTT 3780, along with the measured planetary parameters, render LTT 3780b and c as accessible targets for atmospheric characterization of planets within the same planetary system and spanning the radius valley.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 21