Search for OB-Stars in the SkyMapper Southern Sky Survey

We use the reddening-free Q index Qu-g,g-r=(u-g)-2.099(g-r) to photometrically identify OB-stars in the SkyMapper catalog to retrieve 474 509 candidate OB stars spanning more than half of the Galactic equator strip ( |b|<5∘ ) with a gap in the longitude interval $$50<l<200$$ . A comparison with previously identified OB-associations suggests the presence of potential new, hitherto unknown star groups in the southern sky. An analysis of the dependence of the height z above the Galactic midplane on Q -index confirms that our candidate OB stars reside predominantly in the thin disk.