# WL 17: A Young Embedded Transition Disk

## TL;DR

This study uses high-resolution ALMA observations to reveal a young embedded disk with a 12 AU hole, suggesting early planet formation and providing insights into disk evolution and planetesimal growth.

## Contribution

It demonstrates that a self-consistent model of an embedded disk can explain observations, indicating planet formation processes may occur earlier than previously thought.

## Key findings

- Discovered a 12 AU hole in the disk of WL 17.
- Embedded disk models fit both ALMA data and SED.
- Implication of early planet formation in young disks.

## Abstract

We present the highest spatial resolution ALMA observations to date of the Class I protostar WL 17 in the $\rho$ Ophiuchus L1688 molecular cloud complex, which show that it has a 12 AU hole in the center of its disk. We consider whether WL 17 is actually a Class II disk being extincted by foreground material, but find that such models do not provide a good fit to the broadband SED and also require such high extinction that it would presumably arise from dense material close to the source such as a remnant envelope. Self-consistent models of a disk embedded in a rotating collapsing envelope can nicely reproduce both the ALMA 3 mm observations and the broadband SED of WL 17. This suggests that WL 17 is a disk in the early stages of its formation, and yet even at this young age the inner disk has been depleted. Although there are multiple pathways for such a hole to be created in a disk, if this hole were produced by the formation of planets it could place constraints on the timescale for the growth of planetesimals in protoplanetary disks.