학술논문
TOI-503: The first known brown dwarf-Am star binary from the TESS mission
Document Type
Working Paper
Author
Šubjak, Ján; Sharma, Rishikesh; Carmichael, Theron W.; Johnson, Marshall C.; Gonzales, Erica J.; Matthews, Elisabeth; Boffin, Henri M. J.; Brahm, Rafael; Chaturvedi, Priyanka; Chakraborty, Abhijit; Ciardi, David R.; Collins, Karen A.; Esposito, Massimiliano; Fridlund, Malcolm; Gan, Tianjun; Gandolfi, Davide; García, Rafael A.; Guenther, Eike; Hatzes, Artie; Latham, David W.; Persson, Carina M.; Relles, Howard M.; Schlieder, Joshua E.; Barclay, Thomas; Dressing, Courtney; Crossfield, Ian; Howard, Andrew W.; Rodler, Florian; Zhou, George; Quinn, Samuel N.; Esquerdo, Gilbert A.; Calkins, Michael L.; Berlind, Perry; Stassun, Keivan G.; Albrecht, Simon; Sobrino, Roi Alonso; Beck, Paul; Blažek, Martin; Cabrera, Juan; Carleo, Ilaria; Cochran, William D.; Csizmadia, Szilard; Dai, Fei; Deeg, Hans J.; de Leon, Jerome P.; Eigmüller, Philipp; Endl, Michael; Erikson, Anders; Fukui, Akai; Georgieva, Iskra; González-Cuesta, Lucía; Grziwa, Sascha; Hidalgo, Diego; Hirano, Teruyuki; Hjorth, Maria; Knudstrup, Emil; Korth, Judith; Lam, Kristine W. F.; Livingston, John H.; Lund, Mikkel N.; Luque, Rafael; Mathur, Savita; Rodríguez, Pilar Montanes; Murgas, Felipe; Narita, Norio; Nespral, David; Niraula, Prajwal; Nowak, Grzegorz; Pallé, Enric; Pätzold, Martin; Prieto-Arranz, Jorge; Rauer, Heike; Redfield, Seth; Ribas, Ignasi; Skarka, Marek; Smith, Alexis M. S.; Špoková, Magdalena; Van Eylen, Vincent; Kabáth, Petr
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Abstract
We report the discovery of an intermediate-mass transiting brown dwarf, TOI-503b, from the TESS mission. TOI-503b is the first brown dwarf discovered by TESS and orbits a metallic-line A-type star with a period of $P=3.6772 \pm 0.0001$ days. The light curve from TESS indicates that TOI-503b transits its host star in a grazing manner, which limits the precision with which we measure the brown dwarf's radius ($R_b = 1.34^{+0.26}_{-0.15} R_J$). We obtained high-resolution spectroscopic observations with the FIES, Ond\v{r}ejov, PARAS, Tautenburg, and TRES spectrographs and measured the mass of TOI-503b to be $M_b = 53.7 \pm 1.2 M_J$. The host star has a mass of $M_\star = 1.80 \pm 0.06 M_\odot$, a radius of $R_\star = 1.70 \pm 0.05 R_\odot$, an effective temperature of $T_{\rm eff} = 7650 \pm 160$K, and a relatively high metallicity of $0.61\pm 0.07$ dex. We used stellar isochrones to derive the age of the system to be $\sim$180 Myr, which places its age between that of RIK 72b (a $\sim$10 Myr old brown dwarf in the Upper Scorpius stellar association) and AD 3116b (a $\sim$600 Myr old brown dwarf in the Praesepe cluster). We argue that this brown dwarf formed in-situ, based on the young age of the system and the long circularization timescale for this brown dwarf around its host star. TOI-503b joins a growing number of known short-period, intermediate-mass brown dwarfs orbiting main sequence stars, and is the second such brown dwarf known to transit an A star, after HATS-70b. With the growth in the population in this regime, the driest region in the brown dwarf desert ($35-55 M_J \sin{i}$) is reforesting and its mass range shrinking.
Comment: 26 pages, 14 figures, 6 tables. Accepted to AJ
Comment: 26 pages, 14 figures, 6 tables. Accepted to AJ