The DIRECT Project

The DIRECT project aims to determine direct distances to two important galaxies in the cosmological distance ladder -- M31 and M33 -- using detached eclipsing binaries (DEBs) and Cepheids. I present an overview of the project and some results from follow-up observations.

[1]  Fundamental Properties and Distances of Large Magellanic Cloud Eclipsing Binaries. IV. HV 5936 , 2003, astro-ph/0301296.

[3]  P. Harding,et al.  The Hubble Space Telescope Key Project on the Extragalactic Distance Scale. XIII. The Metallicity Dependence of the Cepheid Distance Scale , 1997, astro-ph/9712055.

[4]  M. Marconi,et al.  Theoretical Models for Classical Cepheids. VIII. Effects of Helium and Heavy-Element Abundance on the Cepheid Distance Scale , 2002, astro-ph/0205147.

[5]  K. Z. Stanek,et al.  The DIRECT Project: Catalogs of Stellar Objects in Nearby Galaxies. II. Eastern Arm and NGC 206 in M31 , 2001, astro-ph/0103441.

[6]  J. Tonry,et al.  DIRECT Distances to Nearby Galaxies Using Detached Eclipsing Binaries and Cepheids. I. Variables in the Field M31B , 1997, astro-ph/9712053.

[7]  R. Henry,et al.  The form of abundance gradients in three nearby spiral galaxies: M33, M81 and M101 , 1995 .

[8]  DIRECT Distances to Nearby Galaxies Using Detached Eclipsing Binaries and Cepheids. IX. Variables in the Field M31Y Discovered with Image Subtraction , 2003, astro-ph/0303307.

[9]  A. Szentgyorgyi,et al.  DIRECT Distances to Nearby Galaxies Using Detached Eclipsing Binaries and Cepheids. VIII. Additional Variables in the Field M33B Discovered with Image Subtraction , 2001, astro-ph/0102274.

[10]  M. Marconi,et al.  Theoretical Models for Classical Cepheids. II. Period-Luminosity, Period-Color, and Period-Luminosity-Color Relations , 1998, astro-ph/9809127.

[11]  DIRECT Distances to Nearby Galaxies Using Detached Eclipsing Binaries and Cepheids. V. Variables in the Field M31F , 1999, astro-ph/9904343.

[12]  DIRECT Distances to Nearby Galaxies Using Detached Eclipsing Binaries and Cepheids. III. Variables in the Field M31C , 1999, astro-ph/9901331.

[13]  A. Herrero,et al.  Differential O and Si Abundances in M33 Early B Supergiants , 2000 .

[14]  J. L. Tonry,et al.  DIRECT Distances to Nearby Galaxies Using Detached Eclipsing Binaries and Cepheids. II. Variables in the Field M31A , 1997 .