A pair of tess planets spanning the radius valley around the nearby mid-m dwarf ltt 3780

We present the confirmation of two new planets transiting the nearby mid-M dwarf LTT 3780 (TIC 36724087, TOI-732, V = 13.07, Ks = 8.204, Rs=0.374 R , Ms=0.401 M , d=22 pc). The two planet candidates are identified in a single TESS sector and are validated with reconnaissance spectroscopy, ground-bas...

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Detalles Bibliográficos
Autores: Cloutier, Ryan, Eastman, Jason D., Rodriguez, Joseph E., Astudillo Defru, Nicola, Bonfils, Xavier, Mortier, Annelies, Watson, Christopher A., Stalport, Manu, Pinamonti, Matteo, Lienhard, Florian, Harutyunyan, Avet, Damasso, Mario, Latham, David W., Collins, Karen A., Massey, Robert, Irwin, Jonathan, Winters, Jennifer G., Charbonneau, David, Ziegler, Carl, Matthews, Elisabeth, Crossfield, Ian J. M., Kreidberg, Laura, Quinn, Samuel N., Ricker, George, Vanderspek, Roland, Seager, Sara, Winn, Joshua, Jenkins, Jon M., Vezie, Michael, Diaz, Rodrigo Fernando
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2020
País:Argentina
Institución:Consejo Nacional de Investigaciones Científicas y Técnicas
Repositorio:CONICET Digital (CONICET)
Idioma:inglés
OAI Identifier:oai:ri.conicet.gov.ar:11336/161405
Acceso en línea:http://hdl.handle.net/11336/161405
Access Level:acceso abierto
Palabra clave:Radial velocity
M dwarf stars
Exoplanet systems
Transit photometry
https://purl.org/becyt/ford/1.3
https://purl.org/becyt/ford/1
Descripción
Sumario:We present the confirmation of two new planets transiting the nearby mid-M dwarf LTT 3780 (TIC 36724087, TOI-732, V = 13.07, Ks = 8.204, Rs=0.374 R , Ms=0.401 M , d=22 pc). The two planet candidates are identified in a single TESS sector and are validated with reconnaissance spectroscopy, ground-based photometric follow-up, and high-resolution imaging. With measured orbital periods of Pb = 0.77 days, Pc = 12.25 days and sizes rp,b = 1.33 ± 0.07 R⊕, rp,c = 2.30 ± 0.16 R⊕, 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 HARPS and HARPS-N, we measure planet masses of mp,b = 2.62+0.48 −0.46 M⊕ and mp,c = 8.6 +1.6 −1.3 M⊕, 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 from 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.