Monthly Notices Of The Royal Astronomical Society
We report the discovery of the 1.008-d, ultrashort period (USP) super-Earth HD 213885b (TOI-141b) 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 ± 0.6 M⊕ 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, whose minimum mass of 19.9 ± 1.4 M⊕ 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.
techniques: photometric, techniques: radial velocities, planets and satellites: detection, planets and satellites: fundamental parameters, planets and satellites: individual: TOI-141, TIC 403224672, HD213885
N. Espinoza; R. Brahm; T. Henning; A. Jordán; C. Dorn; F. Rojas; P. Sarkis; D. Kossakowski; M. Schlecker; M. R. Díaz; J. S. Jenkins; C. Aguilera-Gomez; J. M. Jenkins; J. D. Twicken; K. A. Collins; J. Lissauer; D. J. M. Armstrong; V. Adibekyan; D. Barrado; S. C. C. Barros; M. Battley; D. Bayliss; F. Bouchy; E. M. Bryant; B. F. Cooke; O. D. S. Demaneon; X. Dumusque; P. Figueira; H. Giles; J. Lillo-Box; C. Lovis; L. D. Nielsen; F. Pepe; D. Pollacco; N. C. Santos; S. G. Sousa; S. Udry; P. J. Wheatley; O. Turner; M. Marmier; D, Ségransan; G. Ricker; D. Latham; S. Seager; J. N. Winn; J. F. Kielkopf; R. Hart; G. Wingham; Eric L.N. Jensen; K. G. Hełminiak; A. Tokovinin; C. Briceño; C. Ziegler; N. M. Law; A. W. Mann; T. Daylan; J. P. Doty; N. Guerrero; P. Boyd; I. Crossfield; R. I. Morris; C. E. Henze; and A. D. Chacon.
"HD 213885b: A Transiting 1-D-Period Super-Earth With An Earth-Like Composition Around A Bright (V = 7.9) Star Unveiled By TESS".
Monthly Notices Of The Royal Astronomical Society.