New Estimates of the Scale Height and Surface Density of OB Stars in the Solar Neighborhood

• DOI: 10.1086/301421
• Publication Date: 2002-07-26T18:45:21Z
• Authors: B. Cameron Reed
• Keywords: Scale height; Extinction (optical mineralogy); Star count; Galactic plane

Galactic latitudes and photographic magnitudes for large samples (N ∼ 2000–4000) of OB stars within 10° the plane 4 kpc Sun are used to estimate exponential scale height surface density these objects assuming a barometric extinction model. Depending upon differential absorbing layer, estimates OB-star hOB vary from 25 65 pc 6 80 per 105 pc2. Reasons wide spread in this latter figure discussed. For an layer σ = 100 B-band 2 mag kpc-1, we find 45 26 The total population is estimated at 60,000, their formation rate one every 40 years. Estimates found be essentially independent assumed mean absolute magnitude stars.