Year: 1998
Type: article
Abstract: Hubble Space Telescope ( HST ) images of HK Tauri reveal that the companion star in this 2 4 (340 AU) pre-main-sequence binary system is an entirely nebulous object at visual wavelengths. HK Tau/c appears as two elongated reflection nebulosities separated by a dark lane. Near-infrared adaptive optics observations made at the Canada-France-Hawaii Telescope show a similar morphology and no directly visible star at λ≤2.2 μm. HK Tau/c is strikingly similar to scattered light models of an optically thick circumstellar disk seen close to edge-on and to the HST images of HH 30. HK Tau/c is therefore the first disk to be clearly resolved around an individual star in a young binary system. The disk properties have been constrained by fitting model reflection nebulae to the HST images. The disk has a radius of 105 AU, an inclination of about 5°, a scale height of 3.8 AU at r =50 AU, and is flared. The absence of a point source in the near-IR requires A V >50 mag toward the unseen central star. The thickness of the dark lane establishes a disk mass near 10 -4 M ☉ (~0.1 M Jupiter ) of dust and gas, if the dust grains have interstellar properties and remain fully mixed vertically. With the observed disk radius equal to one-third of the projected separation of the binary, there is a strong possibility that tidal truncation of the circumsecondary disk has occurred in this system.
Source: The Astrophysical Journal
DOI: 10.1086/311479
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W2083293100