Stellar and Circumstellar Properties of the Pre‐Main‐Sequence Binary GV Tau from Infrared Spectroscopy

Abstract

We report spatially resolved spectroscopy of both components of the low-mass pre-main-sequence binary GV Tau. High-resolution spectroscopy in the K and L bands is used to characterize the stellar properties of the binary and to explore the nature of the circumstellar environment. We find that the southern component, GV Tau S, is a radial velocity variable, possibly as a result of an unseen low-mass companion. The strong warm gaseous HCN absorption reported previously by Gibb and coworkers toward GV Tau S was not present during the epoch of our observations. Instead, we detect warm ($500 K) molecular absorption with similar properties toward the northern infrared com-panion, GV Tau N. At the epoch of our observations, the absorbing gas toward GV Tau N was approximately at the radial velocity of the GV Tau molecular envelope, but it was redshifted with respect to the star by $13 km s À1 . One interpretation of our results is that GV Tau N is also a binary and that most of the warm molecular absorption arises in a circumbinary disk viewed close to edge-on.