Phase Curve Analysis of a Brown Dwarf and its Stellar Host: Increasing the Aridity of the Brown-Dwarf Desert with TESS
Abstract
Observations have shown there is a paucity of brown-dwarfs found orbiting within 5 AU of solar-type stars, otherwise known as the "brown-dwarf desert". In this study we revisit the discovery of a brown-dwarf desert member to examine the likelihood that the radial velocity signals which lead to this discovery were indeed due to the existence of a short period brown-dwarf, or if they were instead the result of stellar variability. To do this, we use time series photometry of the host star to measure the amplitude of coherent photometric variations observed by the Transiting Exoplanet Survey Satellite (TESS) and compare these measurements to the range of theoretical ellipsoidal variation and Doppler beaming amplitudes induced by the mass of the speculative brown-dwarf companion. Our preliminary results show that the observed photometric variability amplitudes are much too large to be explained by the presence of a brown-dwarf, thus strengthening the validity of the brown-dwarf desert.
- Publication:
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AAS/Division for Extreme Solar Systems Abstracts
- Pub Date:
- August 2019
- Bibcode:
- 2019ESS.....430912J