Key points are not available for this paper at this time.
A grid of metal-weak spectral-classification standards is used to systematically extend the MK spectral-classification system to F-type stars of the intermediate population II. The present method allows metal-weak program stars to be compared with standards of similar metallicity and effective temperature. The results demonstrate that the intermediate population II is very homogeneous. Excellent agreement is obtained between the classifications of the present extended system and uvby-beta photometric results.
R. O. Gray (Fri,) studied this question.