THE HUBBLE SPACE TELESCOPE EXTRAGALACTIC DISTANCE SCALE KEY PROJECT. XXIII. THE DISCOVERY OF CEPHEIDS IN NGC 3319

摘要

The distance to NGC 3319 has been determined from Cepheid variable stars as part of the Hubble Space Telescope Key Project on the Extragalactic Distance Scale. Thirteen and four epochs of obser- vations, using filters F555W (V) and F814W (I), respectively, were made with the Wide Field Planetary Camera 2. Thirty-three Cepheid variables between periods of 8 and 47 days were discovered. Adopting a Large Magellanic Cloud distance modulus of 18.50 ± 0.10 mag and extinction of E(V -I) = 0.13 mag, a true reddening-corrected distance modulus (based on an analysis employing the ALLFRAME software package) of 30.78 ± 0.14 (random) ± 0.10 (systematic) mag and the extinction of E(V-I) = 0.06 mag were determined for NGC 3319. This galaxy is the last galaxy observed for the HST Ho Key Project.