Program: GN-2010A-DD-6
Title: | Confirmation of binary planetary mass companions to a binary A-star |
PI: | Jenny Patience |
Co-I(s): | Robert De Rosa |
Abstract
With near-infrared photometry and spectra, we propose to observe a close pair of candidate planetary mass companions orbiting a binary A-star. If spectroscopically confirmed as L-type objects, these companions would be the first circumbinary planets orbiting Main Sequence stars. Comparison of the absolute K-band magnitudes with evolutionary models suggests masses of ~5Mjup and ~6Mjup, among the lowest mass planets imaged to date. The companions were detected as part of our volume-limited survey of A-stars within 75pc (GN-2008B-Q-119, PI: Patience) and second epoch observations were recently obtained (GN-2010A-Q-99, PI: De Rosa), indicating that the companions have a proper motion more consistent with the primary than a background object. The youth of the system, 30Myr, combined with the ~4?.5 separation of the companions enabled the detection of these intriguing objects in our snaphot survey. If confirmed, the entire system presents a very interesting case study in the diversity of planetary architectures: the host star is in an eccentric 11-day orbit and is surrounded by a debris disk estimated to be ~30AU in radius, and, at a projected separation of ~250AU, are a pair of planetary mass companions separated from each other by ~10AU.