Stellar Variability in a Forming Massive Star Cluster
Artikel i vetenskaplig tidskrift, 2020

We present a near-infrared (NIR) variability analysis for a 6′ 6′ region, which encompasses the massive protocluster G286.21+0.17. The total sample comprises more than 5000 objects, of which 562 show signs of a circumstellar disk based on their infrared colors. The data includes Hubble Space Telescope observations taken in two epochs separated by 3 yr in the F110W and F160W bands. 363 objects (7% of the sample) exhibit NIR variability at a significant level (Stetson index >1.7), and a higher variability fraction (14%) is found for the young stellar objects with disk excesses. We identified four high amplitude (>0.6 mag) variables seen in both NIR bands. Follow-up and archival observations of the most variable object in this survey (G286.2032+0.1740) reveal a rising light curve over 8 yr from 2011 to 2019, with a K band brightening of 3.5 mag. Overall the temporal behavior of G286.2032+0.1740 resembles that of typical FU Ori objects; however, its pre-burst luminosity indicates it has a very low mass (<0.12 M o˙), making it an extreme case of an outburst event that is still ongoing.

Författare

Yu Cheng

University of Virginia

Morten Andersen

Gemini Observatory South

Jonathan Tan

Chalmers, Rymd-, geo- och miljövetenskap, Astronomi och plasmafysik, Galaktisk astrofysik

University of Virginia

Astrophysical Journal

0004-637X (ISSN) 1538-4357 (eISSN)

Vol. 897 1 51

Ämneskategorier

Astronomi, astrofysik och kosmologi

Miljövetenskap

Datorseende och robotik (autonoma system)

DOI

10.3847/1538-4357/ab93bc

Mer information

Senast uppdaterat

2020-08-28