2011/11/10 by Guillem Anglada-Escudé, Alan P. Boss, Alycia J. Weinberger +4 · 1 citation
Physics and Astronomy · #Astronomy and Astrophysical Research #Scientific Research and Discoveries #Stellar, planetary, and galactic studies #astro-ph.EP
paper · pdf · doi:10.1088/0004-637x/746/1/37
20 pages of text, 9 Figures, 8 tables. Accepted in ApJ (in press)
arxiv created 2011/11/10 · openalex publication_date 2012/01/23 · arxiv updated 2015/06/03 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/31
We have obtained precision astrometry of the planet host M dwarf GJ 317 in the framework of the Carnegie Astrometric Planet Search project. The new astrometric measurements give a distance determination of 15.3 pc, 65% further than previous estimates. The resulting absolute magnitudes suggest that it is metal-rich and more massive than previously assumed. This result strengthens the correlation between high metallicity and the presence of gas giants around low-mass stars. At 15.3 pc, the minimal astrometric amplitude for planet candidate GJ 317b is 0.3 mas (edge-on orbit), just below our astrometric sensitivity. However, given the relatively large number of observations and good astrometric precision, a Bayesian Monte Carlo Markov Chain analysis indicates that the mass of planet b has to be smaller than twice the minimum mass with a 99% confidence level, with a most likely value of 2.5 M Jup . Additional radial velocity (RV) measurements obtained with Keck by the Lick-Carnegie Planet search program confirm the presence of an additional very long period planet candidate, with a period of 20 years or more. Even though such an object will imprint a large astrometric wobble on the star, its curvature is yet not evident in the astrometry. Given high metallicity, and the trend indicating that multiple systems are rich in low-mass companions, this system is likely to host additional low-mass planets in its habitable zone that can be readily detected with state-of-the-art optical and near-infrared RV measurements.