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The Resolved Stellar Content of Local Group Galaxies Currently Forming Stars

P. Massey (Lowell Obs.)
P. Hodge (UW)
N. King (Lowell Obs.)
A. Saha (NOAO)
G. Jacoby (NOAO)
K. Olsen (NOAO)
C. Smith (NOAO)
S. Holmes (Lowell Obs.)

The galaxies of the Local Group serve as our laboratories for understanding star formation and stellar evolution in differing environments: the galaxies currently active in star-formation in the Local Group cover a factor of 10 in metallicity and span a range of Hubble types from dwarf spheroidal to Irr to Sb and Sc. We are proposing a uniform survey (UBVRI, H-alpha, [SII], and [OIII]) of nearby galaxies selected on the basis of current star formation. In the Local Group, this sample includes M31, M33, NGC 6822, IC 1613, IC 10, WLM, Pegasus, and Phoenix; we exclude the Milky Way and Magellanic Clouds, which are being surveyed separately by seve ral groups. We also include Sextans A and Sextans B, located just beyond the Local Group (van den Bergh 1999a, 1999b). Using the new, wide-field Mosaic cameras, we will produce catalogs of UBVRI photometry of roughly 100 million stars, using H-alpha, [SII], and [OIII] to distinguish bona fide stellar members from compact H II regions.

This on-line catalog will answer a number of scientific questions directly, but we believe that the real strength of this survey will be in the science we will enable with 8-10-m class telescopes and the capability of follow-up spectroscopy. In addition, the calibrated images will provide a detailed, uniform atlas of both the stellar and ionized gas components of these galaxies, which will certainly prove useful for a host of other projects.