In addition to the comprehensive data just quoted, there have been numerous determinations of the temperatures of individual bright stars, chiefly by Abbot,[52] Coblentz,[53] Sampson,[54] and H. H. Plaskett.[55] In the main these values confirm the scale given in [Table V], but sometimes considerable differences occur in the values given for individual stars by different investigators. At the same time, each observer is usually reasonably self-consistent, and the deviations must therefore be ascribed to differences of method. Some of the results are reproduced, for illustration, in [Table VI].

[TABLE V]

Class Wilsing RosenbergE.S. King
Color Temperature
E.S. King
Total Radiation
12300°30000°22700°22700°
11450 18000 15200 14900
10250 120011600 11300
9000 9000 8800 8600
7950 7850 7900 7700
6880 6930 7000 6800
5980 6000 6040 5870
5250 5200 5090 4950
4570 4570 4570 4440
3860 3840 3640 3550
3550 3580 3430 3340

It is seen that the effective temperatures of individual hotter stars vary widely among themselves. This is largely a result of the difficulty of making the appropriate correction for atmospheric extinction. It must, then, be supposed that the temperatures derived by spectrophotometric methods are not trustworthy for stars hotter than Class

. The values determined by the earlier observers for the

and

classes are almost certainly too low. Rosenberg’s value of 30,000° for