It is now well established that circumstellar disks, together with bipolar outflows, are a ubiquitous product of low-mass star formation. Disks have been detected during high angular resolution imaging surveys around isolated young stars (e.g. HH 30, Burrows et al. 1996; DM Tau, Guilloteau & Dutrey, 1998) and since most T Tauri stars actually belong to multiple systems the fate of disks in such an environment has also been investigated. This has led to spectacular images of both circumbinary and circumstellar disks in young binary systems (e.g. GG Tau, Dutrey et al. 1994, Roddier et al. 1996; UY Aur, Duvert al. 1998, Close et al. 1998; HK Tau C, Stappelfeldt et al. 1998).
These structures qualitatively agree with theoretical models of binary formation. For instance, the models of Bonnell et al. (1992) form binaries from the collapse of a rotating elongated cloud. During the collapse, each component of the protobinary is surrounded by a circumstellar flattened structure. Unfortunately, the computations do not cover a long enough time span to follow the fate of the circumstellar matter, from the initial thick flattened structures to the final multiple system and its circumstellar environment, and this makes it still difficult to directly compare model predictions and observations.
In this paper, we present high angular resolution, near infrared images of the young triple system HV Tau. The images clearly resolve an almost edge-on circumstellar disk around HV Tau C, the third component of the system. We briefly describe the observations in Sect. 2, derive the basic structural parameters of the disk around HV Tau C and the astrometry of the tight HV Tau AB binary in Sect. 3, and discuss in Sect. 4 the circumstellar properties of the components of the triple system as well as its overall geometry that provides clues to its formation mechanism.
© European Southern Observatory (ESO) 2000
Online publication: April 17, 2000