A SURPRISING DYNAMICAL MASS FOR V773 Tau B

作者：Boden Andrew F^*; Torres Guillermo; Duchene Gaspard; Konopacky Quinn; Ghez A M; Torres Rosa M; Loinard Laurent

来源：Astrophysical Journal, 2012, 747(1): 17.

DOI：10.1088/0004-637X/747/1/17

• stars%26lt
• colfamily%26gt
• fundamental parameters
• stars%26lt
• colfamily%26gt
• individual (V773 Tau)
• stars%26lt
• colfamily%26gt
• pre-main sequence

We report on new high-resolution imaging and spectroscopy on the multiple T Tauri star system V773 Tau over the 2003-2009 period. With these data we derive relative astrometry, photometry between the A and B components, and radial velocity (RV) of the A-subsystem components. Combining these new data with previously published astrometry and RVs, we update the relative A-B orbit model. This updated orbit model, the known system distance, and A-subsystem parameters yield a dynamical mass for the B component for the first time. Remarkably, the derived B dynamical mass is in the range 1.7-3.0 M-circle dot. This is much higher than previous estimates and suggests that like A, B is also a multiple stellar system. Among these data, spatially resolved spectroscopy provides new insight into the nature of the B component. Similar to A, these near-IR spectra indicate that the dominant source in B is of mid-K spectral type. If B is in fact a multiple star system as suggested by the dynamical mass estimate, the simplest assumption is that B is composed of similar similar to 1.2 M-circle dot pre-main-sequence stars in a close (%26lt; 1 AU) binary system. This inference is supported by line-shape changes in near-IR spectroscopy of B, tentatively interpreted as changing RV among components in V773 Tau B. Relative photometry indicates that B is highly variable in the near-IR. The most likely explanation for this variability is circum-B material resulting in variable line-of-sight extinction. The distribution of this material must be significantly affected by both the putative B multiplicity and the A-B orbit.

• 出版日期2012-3-1