749 



TABLE 854.— GALACTIC CONCENTRATION OF STARS OF VARIOUS 

 SPECTRAL CLASSES* 



Part 1. — Number of stars per 100 square degrees 



The data are taken from the publications of the Harvard, McCormick, and Bergedorf 

 Observatories. The spectral groupings are the same as in the preceding table. Absorp- 

 tion accounts for the apparent discrepancy in low latitudes between the numbers of early 

 type stars in the last line of the visual magnitudes and those in the first line of the photo- 

 graphic magnitudes. 



A measure of apparent galactic concentration may be found from the ratios of the star 

 numbers in low latitudes to those in high latitudes. We obtain the figures given in Part 2: 



Part 2. — Index of apparent galactic concentration 



The irregularities here are attributable in part to inadequate sampling. 



Among the stars of the main sequence the true concentration increases with the stellar 

 mass; the true concentration of the red giants is relatively low. The W , O, and .V stars 

 show high apparent concentration to the Milky Way as do the Cepheids, and planetary 

 nebulae ; on the other hand, the long-period variables show little concentration and the 

 cluster-type variables even less. 



* Prepared by A. N. Vyssotsky, University of Virginia. 



SMITHSONIAN PHYSICAL TABLES 



