The Architecture of the V892 Tau System: the Binary and its Circumbinary Disk

Abstract

We present high resolution millimeter continuum and CO line observations for the circumbinary disk around V892 Tau to constrain the stellar and disk properties. The total mass of the two near-equalmass A stars is estimated to be 6.0 ± 0.2 M based on our models of the Keplerian-dominated gas disk rotation. The detection of strong ionized gas emission associated with the two stars at 8 mm, when combined with previous astrometric measurements in the near-infrared, provides an updated view of the binary orbit with a = 7.1 ± 0.1 au, e = 0.27 ± 0.1, and P = 7.7 ± 0.2 yr, which is about half of a previously reported orbital period. The binary orbital plane is proposed to be near coplanar to the circumbinary disk plane (with a mutual inclination of only ∆ = 8 ± 4.2 • ; another solution with ∆ = 113 • is less likely given the short re-alignment timescale). An asymmetric dust disk ring peaking at a radius of 0. 2 is detected at 1.3 mm and its fainter counterparts are also detected at the longer 8 and 9.8 mm. The CO gas disk, though dominated by Keplerian rotation, presents a mild inner and outer disk misalignment. The radial extension of the disk, its asymmetric dust ring, and the presence of a disk warp could all be explained by the interaction between the eccentric binary and the circumbinary disk, which we assume were formed with non-zero mutual inclination. Some tentatively detected gas spirals in the outer disk are likely produced by interactions with the low mass tertiary component located 4 to the northeast. Our analyses demonstrate the promising usage of V892 Tau as an excellent benchmark system to study the details of binary-disk interactions.

Circumbinary and circumstellar discs around the eccentric binary IRAS 04158+2805 — a testbed for binary–disc interaction

“…GW Ori, a hierarchical triple system, shows disc warping and tearing (Kraus et al 2020). Other recent detections of resolved binaries embedded in a circumbinary disc include: L1448 IRS 3B (Tobin et al 2016), L1551 IRS 5 (Cruz-Sáenz de Miera et al 2019), BHB 2007 11 (Alves et al 2019), IRAS 16293-2422 A (Maureira et al 2020) and V892 Tau (Long et al 2021). In only a limited number of cases information about the binary dynamics is also available (e.g., Cazzoletti et al 2017;Price et al 2018b;Long et al 2021).…”