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Up: Revised photometric distances

2. Observations and reductions

The galaxies UGCA 86, UGCA 92, UGCA 105, NGC 1569, and Cas 1 were observed in February 5-7, 1995 at the Nordic 2.5-meter telescope in the V and I bands of the Kron-Cousins system. The observations were carried out with a TK 1024A CCD chip having 1024 by 1024 pixels each 24 microns in size. It provided a tex2html_wrap_inline1274 field of view with the resolution of tex2html_wrap_inline1276 per pixel. The CCD quantum efficiency is about 70% in each of the bands, and the read-out noise is tex2html_wrap_inline1278. The frames of the galaxies were obtained under quite good photometric conditions with a seeing of FMHM tex2html_wrap_inline1280. Table 1 (click here) describes the exposures.

After subtracting dark frame, flat-fielding and cleaning of cosmic ray events the photometric processing of the frames was performed with DAOPHOT and ALLSTAR packages (Stetson 1987). Equatorial photometric standards from Landolt (1992) were observed in order to transform instrumental magnitudes into the standard V and I system. According to our estimate the total error in the zero-point does not exceed 0.05 mag for any of the galaxies.

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