Galactic HII regions. I. Stellar distances

The standard deviation of individual stellar distances in a cluster is typically 20% per stellar distance, and the error in the mean distance to the cluster is typically +/-10%. Final mean distances of nine common objects with very long baseline interferometry parallax distances show a 1:1 correspondence. Further, comparison with previous catalogs of HII regions in these quadrants shows a 50% reduction in scatter for the distance to Perseus spiral arm objects in the same region, and a reduction by ~1/2^0.5^ in scatter around a common angular velocity relative to the Sun {Omega}-{Omega}_0_(km/s/kpc).

The purpose of the catalog is to provide a foundation for more detailed large-scale Galactic spiral structure and dynamics (rotation curve, density wave streaming) studies in the 2nd and 3rd quadrants, which from the Sun's location is the most favorably viewed section of the Galaxy.