AAS 205th Meeting, 9-13 January 2005
Session 73 Distances, the CMB and the Sunyaev-Zeldovich Effect
Oral, Tuesday, January 11, 2005, 10:00-11:30am, Golden Ballroom

Previous   |   Session 73   |   Next

[73.04] Determining Accurate Distances to Nearby Galaxies

A.Z. Bonanos, K.Z. Stanek (Harvard-Smithsonian CfA)

Distances to nearby galaxies are only known with an accuracy of 10-15%. The current anchor galaxy of the extragalactic distance scale is the Large Magellanic Cloud, which has large (10-15%) systematic uncertainties associated with it, because of its morphology, its non-uniform reddening and the unknown metallicity dependence of the Cepheid period-luminosity relation. The DIRECT Project aims to obtain a new anchor galaxy for the distance scale by measuring direct, accurate (to 5%) distances to two Local Group galaxies, M31 and M33 with detached eclipsing binaries and the Baade-Wesselink method for Cepheids. It involves a massive variability survey of these galaxies and subsequent photometric and spectroscopic follow-up of the detached binaries and Cepheids. I will describe the progress on obtaining the direct distance to a detached eclipsing binary in M33. I will also present the results of the first CCD variability study of the Draco Dwarf Spheroidal galaxy and the RR Lyrae distance derived. Finally, I will describe a "hybrid" method of discovering Cepheids with ground-based telescopes using image subtraction and then following them up with the HST to derive Cepheid period-luminosity distances.

Previous   |   Session 73   |   Next

Bulletin of the American Astronomical Society, 36 5
© 2004. The American Astronomical Society.