BVR photometry of the resolved dwarf galaxy Ho IX^*

¹ Institute of Astronomy, Bulgarian Academy of Sciences and Isaak Newton Institute of Chile, Bulgarian Branch, 72 Tsarigradsko Chausse Blvd. 1784 Sofia, Bulgaria e-mail: tsgeorg@astro.bas.bg
² Astronomisches Institut der Ruhr-Universität Bochum, Universitätsstr. 150, 44780 Bochum, Germany e-mail: bomans@astro.ruhr-uni-bochum.de

Received: 3 September 2001
Accepted: 14 January 2004

Abstract

We present BVR CCD photometry down to limiting magnitude  mag for 232 starlike objects and 11 diffuse objects in a field of Ho IX. The galaxy is a gas-rich irregular dwarf galaxy possibly very close to M 81, which makes it especially interesting in the context of the evolution of satellite galaxies and the accretion of dwarf galaxies. Investigations of Ho IX were hampered by relatively large contradictions in the magnitude scale between earlier studies. With our new photometry we resolved these discrepancies. The color magnitude diagram (CMD) of Ho IX is fairly typical of a star-forming dwarf irregular, consistent with earlier results. Distance estimates from our new CMD are consistent with Ho IX being very close to M 81 and therefore being a definite member of the M 81 group, apparently in very close physical proximity to M 81.