Publication details

Evolution of BD-14 3065b (TOI-4987b) from giant planet to brown dwarf as possible evidence of deuterium burning at old stellar ages

Authors	SUBJAK Jan LATHAM David W QUINN Samuel N BERLIND Perry CALKINS Michael L ESQUERDO Gilbert A BRAHM Rafael CABALLERO Jose A COLLINS Karen A GUENTHER Eike JANÍK Jan KABÁTH Petr SCHWARZ Richard P TAN Thiam-Guan VANZI Leonardo ZAMBELLI Roberto ZIEGLER Carl JENKINS Jon M MIRELES Ismael SEAGER Sara SHPORER Avi STRIEGEL Stephanie WINN Joshua N
Year of publication	2024
Type	Article in Periodical
Magazine / Source	ASTRONOMY & ASTROPHYSICS
MU Faculty or unit	Faculty of Science
Citation
web	https://www.aanda.org/articles/aa/pdf/2024/08/aa49028-23.pdf
Doi	http://dx.doi.org/10.1051/0004-6361/202349028
Keywords	techniques: photometric; techniques: radial velocities; techniques: spectroscopic; planets and satellites: gaseous planets; brown dwarfs
Description	The present study confirms BD-14 3065b as a transiting planet-brown dwarf in a triple-star system, with a mass near the deuterium-burning boundary. BD-14 3065b has the largest radius observed within the sample of giant planets and brown dwarfs around post-main sequence stars. Its orbital period is 4.3 days and it transits a subgiant F-type star with a mass of M-* = 1.41 +/- 0.05 M-circle dot, a radius of R-* = 2.35 +/- 0.08 R-circle dot, an effective temperature of T-eff = 6935 +/- 90 K, and a metallicity of -0.34 +/- 0.05 dex. By combining TESS photometry with high-resolution spectra acquired with the TRES and Pucheros+ spectrographs, we measured a mass of M-p = 12.37 +/- 0.92 M-Jup and a radius of R-p = 1.926 +/- 0.094 R-Jup. Our discussion of potential processes that could be responsible for the inflated radius led us to conclude that deuterium burning is a plausible explanation for the heating taking place in BD-14 3065b's interior. Detections of the secondary eclipse with TESS photometry enabled a precise determination of the eccentricity, e(p) = 0.066 +/- 0.011, and reveal that BD-14 3065b has a brightness temperature of 3520 +/- 130 K. With its unique characteristics, BD-14 3065b presents an excellent opportunity to study its atmosphere via thermal emission spectroscopy.