2013/01/03 by H. Khandrika, Harish Khandrika, Adam Burgasser +6 · 2 citations
Physics and Astronomy · #Adaptive optics and wavefront sensing #Astrobiology #Astronomy #Astronomy and Astrophysical Research #Astrophysics #Brown dwarf #Circumbinary planet #Photometry (optics) #Physics #Stars #Stellar, planetary, and galactic studies #astro-ph.SR
paper · pdf · doi:10.1088/0004-6256/145/3/71
arxiv created 2013/01/03 · openalex publication_date 2013/02/08 · arxiv updated 2013/02/12 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Using the Gemini infrared camera on the 3 m Shane telescope at Lick Observatory, we have searched for broadband J and K ' photometric variability for a sample of 15 L- and T-type brown dwarfs, including 7 suspected spectral binaries. Four of the dwarfs—2MASS J0939−2448, 2MASS J1416+1348A, 2MASS J1711+2232, and 2MASS J2139+0220—exhibit statistically significant variations over timescales ranging from ∼0.5 hr to 6 days. Our detection of variability in 2MASS J2139+0220 confirms that reported by Radigan et al., and periodogram and phase dispersion minimization analysis also confirms a variability period of approximately 7.6 ± 0.2 hr. Remarkably, two of the four variables are known or candidate binary systems, including 2MASS J2139+0220, for which we find only marginal evidence of radial velocity variation over the course of a year. This result suggests that some spectral binary candidates may appear as such due to the blending of cloudy and non-cloudy regions in a single "patchy" atmosphere. Our results are consistent with an overall variability fraction of 35% ± 5%, with no clear evidence of greater variability among brown dwarfs at the L dwarf/T dwarf transition.