Discovery of a young low-mass brown dwarf transiting a fast-rotating F-type star by the Galactic Plane eXoplanet (GPX) survey

Benni, P.; Burdanov, A. Y.; Krushinsky, V. V.; Bonfanti, A.; Hébrard, G.; Almenara, J. M.; Dalal, S.; Demangeon, O. D. S.; Tsantaki, M.; Pepper, J.; Stassun, K. G.; Vanderburg, A.; Belinski, A.; Kashaev, F.; Barkaoui, K.; Kim, T.; Kang, W.; Antonyuk, K.; Dyachenko, V. V.; Rastegaev, D. A.; Beskakotov, A.; Mitrofanova, A. A.; Pozuelos, F. J.; Kuznetsov, E. D.; Popov, A.; Kiefer, F.; Wilson, P. A.; Ricker, G.; Vanderspek, R.; Latham, D. W.; Seager, S.; Jenkins, J. M.; Sokov, E.; Sokova, I.; Marchini, A.; Papini, R.; Salvaggio, F.; Banfi, M.; Baştürk, Ö.; Torun, Ş.; Yalçınkaya, S.; Ivanov, K.; Valyavin, G.; Jehin, E.; Gillon, M.; Pakštienė, E.; Hentunen, V. -P.; Shadick, S.; Bretton, M.; Wünsche, A.; Garlitz, J.; Jongen, Y.; Molina, D.; Girardin, E.; Grau Horta, F.; Naves, R.; Benkhaldoun, Z.; Joner, M. D.; Spencer, M.; Bieryla, A.; Stevens, D. J.; Jensen, E. L. N.; Collins, K. A.; Charbonneau, D.; Quintana, E. V.; Mullally, S. E.; Henze, C. E.
Referencia bibliográfica

Monthly Notices of the Royal Astronomical Society

Fecha de publicación:
8
2021
Número de autores
67
Número de autores del IAC
1
Número de citas
13
Número de citas referidas
9
Descripción
We announce the discovery of GPX-1 b, a transiting brown dwarf with a mass of 19.7 ± 1.6 MJup and a radius of 1.47 ± 0.10 RJup, the first substellar object discovered by the Galactic Plane eXoplanet (GPX) survey. The brown dwarf transits a moderately bright (V = 12.3 mag) fast-rotating F-type star with a projected rotational velocity $v\sin {\, i_*}=40\pm 10$ km s-1. We use the isochrone placement algorithm to characterize the host star, which has effective temperature 7000 ± 200 K, mass 1.68 ± 0.10 $\mathrm{\it M}_\odot$, radius 1.56 ± 0.10 $\mathrm{\it R}_\odot$, and approximate age $0.27_{-0.15}^{+0.09}$ Gyr. GPX-1 b has an orbital period of ~1.75 d and a transit depth of 0.90 ± 0.03 per cent. We describe the GPX transit detection observations, subsequent photometric and speckle-interferometric follow-up observations, and SOPHIE spectroscopic measurements, which allowed us to establish the presence of a substellar object around the host star. GPX-1 was observed at 30-min integrations by TESS in Sector 18, but the data are affected by blending with a 3.4 mag brighter star 42 arcsec away. GPX-1 b is one of about two dozen transiting brown dwarfs known to date, with a mass close to the theoretical brown dwarf/gas giant planet mass transition boundary. Since GPX-1 is a moderately bright and fast-rotating star, it can be followed-up by the means of the Doppler tomography.