VizieR Online Data Catalog: Spiral structure as revealed by O and B stars (Chen+, 2019)

The 6858 new OB star candidates are selected from the VPHAS+ DR2 and Gaia DR2 catalogues.

The VPHAS+ Survey (Drew et al. 2014MNRAS.440.2036D, Cat. J/MNRAS/440/2036) collected images in the SDSS u, g, r, i broad bands and the Hα narrow band using the OmegaCAM imager (Kuijken 2011Msngr.146....8K) on the VLT Survey Telescope (VST). The survey is designed to cover 2000deg² of the Galactic plane in the southern hemisphere of Galactic latitude |b|<5° and Galactic longitude -150°<l<40°, and a Galactic bulge extension of |b|<10° near the Galactic centre. The VPHAS+ DR2, released in 2016, contains PSF and aperture photometry of 319 million point-like sources covering 629deg² of the planned VPHAS+ footprint.

To exclude contaminations of subluminous and overluminous OB stars and stars of spectral types B4 and later, we combine the VPHAS+ photometry with the Gaia DR2 data (Gaia Collaboration et al. 2018A&A...616A...1G, Cat. I/345). Gaia DR2 provides high precision photometric measurements of over 1.4 billion sources in G, G_BP, and G_RP bands. The Gaia G band covers the entire optical wavelength ranging between 330 and 1050nm. Gaia DR2 also releases high-quality parallax and proper motion measurements of 1.3 billion sources.

(2 data files).