HST color-magnitude diagrams of 74 galactic globular clusters in the HST and bands^*

¹ Dipartimento di Astronomia – Università di Padova, 35122 Padova, Italy e-mail: piotto@pd.astro.it; deangeli@pd.astro.it; recio@pd.astro.it
² Astronomy Department, University of California, Berkeley, CA 94720, USA e-mail: king@glob.berkeley.edu; craig@sosin.org
³ California Institute of Technology, MS 105-24, Pasadena, CA 91125, USA e-mail: george@deimos.caltech
⁴ European Southern Observatory, 85748 Garching bei Munich, Germany e-mail: mzoccali@eso.org; gmeylan@eso.org; arenzini@eso.org
⁵ European Southern Observatory, Casilla 19001, Santiago, Chile
⁶ Osservatorio Astronomico, 35122 Padova, Italy e-mail: riello@pd.astro.it
⁷ Physics and Astronomy Department, University of California, Los Angeles, CA 90024, USA e-mail: rmr@astro.ucla.edu
⁸ Space Telescope Science Institute, Baltimore, MD 21218, USA

Corresponding author: G. Piotto, piotto@pd.astro.it

Received: 3 April 2002
Accepted: 30 May 2002

Abstract

We present the complete photometric database and the color-magnitude diagrams for 74 Galactic globular clusters observed with the HST/WFPC2 camera in the and bands. A detailed discussion of the various reduction steps is also presented, and of the procedures to transform instrumental magnitudes into both the HST and flight system and the standard Johnson and systems. We also describe the artificial star experiments which have been performed to derive the star count completeness in all the relevant branches of the color magnitude diagram. The entire photometric database and the completeness function will be made available on the Web immediately after the publication of the present paper.