V1094 Sco: a rare giant multi-ringed disk around a T Tauri star

TL;DR

This paper reports the discovery and detailed analysis of a rare, large, multi-ringed protoplanetary disk around the T Tauri star V1094 Sco, revealing its structure, extent, and potential implications for disk evolution and planet formation.

Contribution

It provides the first detailed ALMA observations of a giant, multi-ringed disk in Lupus, expanding understanding of disk diversity and formation mechanisms.

Findings

The disk extends up to 300 AU, larger than typical Lupus disks.

It contains two gap/ring pairs at 100/130 AU and 170/220 AU.

Disks of this size are very rare, with only about 2.1% in Lupus showing similar extent.

Abstract

A wide variety of ring-like dust structures has been detected in protoplanetary disks, but their origin and frequency are still unclear. We characterize the structure of an extended, multi-ringed disk discovered serendipitously in the ALMA Lupus disk survey and put it in the context of the Lupus disk population. ALMA observations in Band 6 at 234 GHz and Band 7 at 328 GHz at 0.3" resolution toward the K6 star V1094 Sco in Lupus III are presented, and its disk structure is analyzed. The spectral index $\alpha_{mm}$ is determined in the inner 150 AU of the disk. The ALMA continuum data show a very extended disk with two gap/ring pairs. The gaps are located at 100 AU and 170 AU, the bright rings at 130 AU and 220 AU. Continuum emission is detected out to a 300 AU distance, similar to IM Lup but a factor of 5 larger than typically found for Lupus disks at this sensitivity and resolution. The bright central region of the disk (within 35 AU) is possibly optically thick at 1 mm wavelengths, and has a brightness temperature of only 13 K. The spectral index increases between the inner disk and the first ring, at the location of the first gap. Due to the low temperature of the disk midplane, snow lines can be excluded as the drivers behind the ring and gap formation in this disk. Disks the size of V1094 Sco are rare, and only 2.1+-1.5% of disks in Lupus show continuum emission beyond 200 AU. Possible connections between the large primordial disk population, transition disks, and exoplanets are discussed.