Characterization of the Companion to $\mu$ Her
Abstract
Her is a nearby quadruple system with a G-subgiant primary and several low mass companions arranged in a 2+2 architecture. While the BC components have been well characterized, the Ab component has been detected astrometrically and with direct imaging but there has been some confusion over its nature, in particular whether the companion is stellar or substellar. Using near-infrared spectroscopy we are able to estimate the spectral type of the companion as a M41V star. In addition, we have measured the astrometry of the system for over a decade. We combined the astrometry with archival radial velocity measurements to compute an orbit of the system. From the combined orbit, we are able to compute the mass sum of the system. Using the estimated mass of the primary, we estimate the mass of the secondary as 0.32 M_sun, which agrees with the estimated spectral type. Our computed orbit is preliminary due to the incomplete orbital phase coverage, but it should be sufficient to predict ephemerides over the next decade.
Keywords
Cite
@article{arxiv.1604.06494,
title = {Characterization of the Companion to $\mu$ Her},
author = {Lewis C. Roberts and Brian D. Mason and Jonathan Aguilar and Joseph Carson and Justin Crepp and Charles Beichman and Douglas Brenner and Rick Burruss and Eric Cady and Statia Luszcz-Cook and Richard Dekany and Lynne Hillenbrand and Sasha Hinkley and David King and Thomas G. Lockhart and Ricky Nilsson and Rebecca Oppenheimer and Ian R. Parry and Laurent Pueyo and Emily L. Rice and Anand Sivaramakrishnan and Rémi Soummer and Gautam Vasisht and Aaron Veicht and Ji Wang and Chengxing Zhai and Neil T. Zimmerman},
journal= {arXiv preprint arXiv:1604.06494},
year = {2016}
}
Comments
7 pages, 5 figures, Accepted to Astronomical Journal