On the Nature of V2282 Sgr

Abstract

The star V2282 Sgr is positionally consistent with a strong Chandra X-ray and a Spitzer/IRAC mid-infrared source. We derived its long-term I-band light curve from the photographic archives of the Asiago and Catania Observatories, covering the years from 1965 to 1984. Also, CCD RC photometry of 2009 was re-analyzed. Optical spectra were collected at the Loiano Observatory in 2011 and 2012. J,H,Ks photometry, obtained from several sources in different epochs was compared and the Spitzer images were re-analyzed. V2282 Sgr was found to be irregular variable in all wavelengths. Spectroscopically, it shows strong emission features (H Balmer lines, [N II] 6584Å and [O III] 5007/4959Å) while the Na I D-doublet is very strong, indicating a circumstellar envelope. A single thermal energy distribution cannot reproduce the observed SED, while it can be explained as the sum of a G-type star plus a variable circumstellar disk, which mimics YSO of class 0/I. Most likely, V2282 Sgr is a 1–2 M⊙ mass pre-main-sequence star with an accretion disk.

Keywords

• stars: pre-main-sequence, protostars
• variables: t tauri: individual (v2282 sgr)