SIMBAD references

Reddenings, absolute magnitudes, and distances (D) based on both UBV-beta photometry and MK-system spectral classifications are computed and compared for 287 stars of spectral types 04-B2.5. While overall agreement is very good, D_UBV–beta/DMK) = 1.06 ± 0.39 (s.d.), significant trends in photometric vs. spectroscopic absolute magnitudes and distances as a function of both absolute magnitude and photometric vs. spectroscopic luminosity classification are evident. Prescriptions as to whether one is likely to over- or under-estimate photometric as compared to spectroscopic distances in given circumstances are developes. Almost all of the standard deviation in D_UBV-beta/D-MK is attributable to differences in inferred absolute magnitudes.