HD 213885b: a transiting 1-d-period super-Earth with an Earth-like composition around a bright (V=7.9) star unveiled by TESS

Espinoza, Nestor; Brahm, Rafael; Henning, Thomas; Jordan, Andres; Dorn, Caroline; Rojas, Felipe; Sarkis, Paula; Kossakowski, Diana; Schlecker, Martin; Diaz, Matias R.; Jenkins, James S; Aguilera-Gomez, Claudia; Jenkins, Jon M.; Twicken, Joseph D.; Collins, Karen A.; et. al.

Abstract

We report the discovery of the 1.008-d, ultrashort period (USP) super-EarthHD213885b (TOI141b) orbiting the bright (V= 7.9) star HD 213885 (TOI-141, TIC 403224672), detected using photometry from the recently launched TESS mission. Using FEROS, HARPS, and CORALIE radial velocities, we measure a precise mass of 8.8 +/- 0.6M. for this 1.74 +/- 0.05 R. exoplanet, which provides enough information to constrain its bulk composition - similar to Earth's but enriched in iron. The radius, mass, and stellar irradiation of HD 213885b are, given our data, very similar to 55 Cancri e, making this exoplanet a good target to perform comparative exoplanetology of short period, highly irradiated super-Earths. Our precise radial velocities reveal an additional 4.78-d signal which we interpret as arising from a second, non-transiting planet in the system, HD 213885c, whoseminimum mass of 19.9 +/- 1.4M. makes it consistent with being a Neptune-mass exoplanet. The HD 213885 system is very interesting from the perspective of future atmospheric characterization, being the second brightest star to host an USP transiting super-Earth (with the brightest star being, in fact, 55 Cancri). Prospects for characterization with present and future observatories are discussed.

Más información

Título según WOS: HD 213885b: a transiting 1-d-period super-Earth with an Earth-like composition around a bright (V=7.9) star unveiled by TESS
Título según SCOPUS: HD 213885b: A transiting 1-d-period super-Earth with an Earth-like composition around a bright (V = 7.9) star unveiled by TESS
Título de la Revista: MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
Volumen: 491
Número: 2
Editorial: Oxford Academic
Fecha de publicación: 2020
Página de inicio: 2982
Página final: 2999
Idioma: English
DOI:

10.1093/mnras/stz3150

Notas: ISI, SCOPUS