Previous abstract Next abstract

Session 14 - Milky Way Galaxy.
Display session, Monday, January 15
North Banquet Hall, Convention Center

[14.10] The Radial Scale Length of the Galactic Disk

R. M. Humphreys, J. A. Larsen (Univ. Minn.)

We have used star counts from the APS Catalog of the POSS I to determine a number of fundamental galactic parameters including the axial ratio of the halo and the Sun's distance from the galactic plane. In this poster we present our results for the radial scale length of the disk. Our studies take advantage of the Catalog's uniform and complete coverage to about 20th magnitude over two-thirds of the sky to minimize the statistical uncertainties and effects of local density variations in previous star count studies.

We have compared the star counts along the center/anti-center axis in three 16 sq. deg. fields at each of the galactic latitudes of +20, +30, +40, and +50 degrees for a total of 24 fields. We compare the observed ratios with the predictions of various galactic models and conclude that the scale length of the disk is significantly smaller than normally assumed.

Program listing for Monday