CCD photometry of resolved dwarf irregular galaxies. II - DDO 187. III - GR 8

Aparicio, A.; Garcia-Pelayo, J. M.; Moles, M.
Bibliographical reference

Astronomy and Astrophysics Supplement Series (ISSN 0365-0138), vol. 74, no. 3, Sept. 1988, p. 367-384. Research supported by Consejo Superior de Investigaciones Cientificas and Universidad de Chile.

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CCD photometry of resolved dwarf irregular galaxies was obtained with the 4-m Cerro Tololo Interamerican Observatory telescope in February 1985. BV data from 77 stars in DDO 187 are used to infer a distance modulus of 28.2 + or - 0.6, placing this galaxy out of the Local Group, at a distance of 4.4 + or - 1.0 Mpc. In the second part, UBV photometry of 142 resolved stars in GR 8 is presented. The results show a distance modulus of 25.0 for GR 8. It is suggested that metal enriched gas loss is required (probably together with a low upper mass limit in the IMF) to explain the metallicity of this galaxy, and that a star formation burst mode is necessary to explain the blue colors of GR 8.