The G 305 Star-forming Region. II. Irregular Variable Stars

We present a catalog of 167 newly discovered, irregular variables spanning $\sim$7 deg${^2}$ area that encompasses the G 305 star-forming complex, one most luminous giant H II regions in Galaxy. aim to unveil and characterize young stellar object (YSO) population region by analyzing $K_{\rm s}$-band variability $JHK_{\rm s}$ infrared colors from {\it VISTA Variables V\'ia L\'actea} (VVV) survey. Additionally, SDSS-IV APOGEE-2 spectra selected objects are analyzed. The sample show relatively high amplitudes ($0.661<\Delta K_{\rm S} <3.521$ mag). Most them resemble sources with outbursts amplitude $>1$ mag duration longer than few days, typically at least year, known as Eruptive Variables}. About 60% likely be Class II/Flat/I objects. This is also confirmed spectral index $\alpha$ when available. From analysis near-infrared region, another 122 stars classified YSOs, displays some variability. measured effective temperature $T_{\rm eff}$ peak around 4000K they slightly super-solar metal abundance. modal radial velocity approximately $-$41 km/s. Combining available catalogs YSOs our data, we investigate spatial distributions 700 YSOs. They clearly concentrated within central cavity formed massive clusters Danks 1 2. calculated surface density for entire 0.025 YSOs/pc$^{-2}$, while contains 10 times more per (0.238 YSOs/pc$^{-2}$).