COUNTS AND COLORS OF FAINT STARS IN 5 FIELDS NEAR THE NORTH GALACTIC POLE
Abstract
Faint star number counts in the photographic J band and (B - V) colour distributions are presented for a 1.08 deg(2) field near the North Galactic Pole, Due to the excellent star/galaxy discrimination we count stars as faint as J = 23. We compare the number counts and colour distributions in 5 adjacent fields near SA57. The number counts and colour distributions are in very good agreement with previous data. However, we find that the large field-to-field scatter in the colour distributions, which we argue is real, might prevent us setting strong limits on Galactic structure. A simple two component standard model, Bahcall and Soneira (1984), fits the number counts reasonably well at the bright J < 21, but fails notably at the faint end, even if a third component is added, as in Reid and Majewski (1993). The standard models are in good agreement with both the number counts and colour distribution at 20 < V < 21. Although the standard models bimodal shape of the colour distribution compares well with the data at 21 < V < 21.5, the number counts of stars are underestimated.
Description
Keywords
GALAXY, STRUCTURE, GALAXY, STELLAR CONTENT, STARS, STATISTICS