Star-forming regions at the periphery of the supershell surrounding the Cyg OB1 association - I. The star cluster vdB 130 and its ambient gas and dust medium

Abstract

Stellar population and the interstellar gas-dust medium in the vicinity of the open star cluster vdB 130 are analysed using optical observations taken with the 6 m telescope of the Special Astrophysical Observatory of Russian Academy of Sciences and the 125 cm telescope of the Sternberg Astronomical Institute, Lomonosov Moscow State University along with the data of Spitzer and Herschel. Based on proper motions and BV and JHKs Two Micron All Sky Survey photometric data, we select additional 36 stars as probable cluster members. Some stars in vdB 130 are classified as B stars. Our estimates of minimum colour excess, apparent distance modulus and the distance are consistent with young age (from 5 to 10 Myr) of the cluster vdB 130. We suppose the large deviations from the conventional extinction law in the cluster direction, with RV ~ 4-5. The cluster vdB 130 appears to be physically related to the supershell around Cyg OB1, a cometary CO cloud, ionized gas and regions of infrared emission. There are a few regions of bright mid-infrared emission in the vicinity of vdB 130. The largest of them is also visible on Ha and [S II] emission maps. We suggest that the infrared blobs that coincide in projection with the head of the molecular cloud are HII regions, excited by the cluster B stars. Some signatures of a shock front are identified between these IR-bright regions.