How Old is the Gliese 504 System

ON THE AGE OF GLIESE 504

Authors:

Fuhrmann et al

Abstract:

Direct imaging observations of the solar-type star Gl 504 have recently uncovered a faint companion that, on the supposition that the host star has an age of $160_{-60}^{+350}$ Myr, was announced to be a $4_{-1.0}^{+4.5}$ MJ Jovian exoplanet. Here we present the observational evidence that Gl 504 A is an evolved turn-off star of about solar age and by inference its faint companion a low-mass brown dwarf. As with our previous work on Gl 504 A several years ago, we suggest the accretion of a substellar object to account for the otherwise unexplained high rotation of Gl 504 A. We also propose that with the distant Gl 504 B we may now well be facing the driving agent for the former merger.