Possible Proplyd Disk Discovered In Rubin Observatory’s First-Look Image

On 23 June 2025, the public got its first look at images from the NSF–DOE Vera C. Rubin Observatory — and the discoveries are already starting to roll in.

Trifid and Lagoon

One of the first-look images from Rubin features two photogenic star-forming regions in the Milky Way: the Trifid Nebula (Messier 20) and the Lagoon Nebula (Messier 8). The image, which was constructed from 678 exposures totaling 7.2 hours of observations, demonstrates Rubin’s ability to quickly cover large swaths of sky.

Disk Detected

Published today in the Research Notes of the AAS, Mahdi Zamani (Zamani Scientific Visualizations & Imaging) and Travis Rector (University of Alaska Anchorage) reported the results of their search for proplyds in the Rubin image of the Trifid and Lagoon nebulae. The team detected one candidate circumstellar or protoplanetary disk on the edge of the Trifid Nebula, surrounded by tenuous, filamentary clouds of gas and dust.

The Rubin data don’t show evidence for ionized gas surrounding the disk, so it’s not yet clear if the object should be classified as a proplyd. The disk has a projected distance of 7.5 light-years from HD 164492A, the O-type star whose intense radiation is responsible for energizing the surrounding nebula, and may also be capable of ionizing the disk studied here.

Disk Detected

This disk candidate is remarkable for both its size and location. With an estimated diameter of 4,000 au, it’s larger than most known circumstellar disks. Finding a disk outside the nearby Orion Nebula is also comparatively rare, since searches in more distant star-forming regions require finer resolution than the nearby Orion Nebula. (Orion is about 1,300 light-years away, and the Trifid Nebula is about 4,000 light-years away.)

Researchers have searched the Trifid Nebula previously for signs of protoplanetary disks, but while those searches found evidence for disks around hot stars near the center of the cluster, this particular disk candidate went undetected.

Previous searches likely didn’t cover a large enough area of the nebula, or perhaps lacked the resolution needed to differentiate between the dusty disk and the nearby filamentary gas clouds. With Rubin’s broad field of view and precise resolution, the observatory was well-positioned to spot this disk candidate.

Citation

“The Potential Discovery of a Circumstellar Disk in M20 from Rubin First Look,” Mahdi Zamani and T. A. Rector 2025 Res. Notes AAS 9 172. doi:10.3847/2515-5172/ade982 (open access)

Astrobiology, Astronomy,