The G305 Star-forming Region. I. Newly Classified Hot Stars Show affiliations

Borissova, Jura; Roman-Lopes, Alexandre; Covey, Kevin; Medina, Nicolas; Kurtev, Radostin; Roman-Zuniga, Carlos; Kuhn, M. A.; Contreras Peña, Carlos; Lucas, Philip; Ramirez Alegria, Sebastian; Minniti, Dante; Kounkel, Marina; Stringfellow, Guy; Barbá, Rodolfo H.; Suárez, Genaro
The Astronomical Journal, Volume 158, Issue 1, article id. 46, 13 pp. (2019).


The relatively nearby star-forming complex G305 is one of the most luminous H II regions in the Galaxy, and it contains several sites and epochs of star formation. Using a combination of near-infrared photometry from “Vista Variables in Via Lactea” ESO Large Public Survey, SDSS-IV APOGEE-2 spectra, and Gaia DR2 photometry and astrometry, we report on 29 OB type, Wolf─Rayet, and emission-line stars, 18 of which are newly classified. Most of these hot stars belongs to the main sequence, although some stars of class I are also proposed. The mean radial velocity is RV = −41.8 {km} {{{s}}}-1. The average spectroscopic distance is 3.2 ± 1.6 kpc, while the Gaia DR2 average distance is 3.7 ± 1.8 kpc. Eight objects show light-curve variations with amplitudes greater than 0.5 mag in the K S band. Based on Vista Variables in the Vía Láctea (VVV); SDSS-IV APOGEE-2 and Gaia DR2 data.