  We present HST/WFPC2 observations of UGC 4483, an irregular galaxy in the
M81/NGC 2403 complex. Stellar photometry was carried out with HSTphot, and is
complete to V ~ 26.0 and I ~ 24.7. We measure the red giant branch tip at I =
23.56 +/- 0.10 and calculated a distance modulus of (m-M)o = 27.53 +/- 0.12
(corresponding to a distance of 3.2 +/- 0.2 Mpc), placing UGC 4483 within the
NGC 2403 subgroup. We were able to measure properties of a previously-known
young star cluster in UGC 4483, finding integrated magnitudes of V = 18.66 +/-
0.21 and I = 18.54 +/- 0.10 for the stellar contribution (integrated light
minus Halpha and [OIII] contribution), corresponding to an age of ~10-15 Myr
and initial mass of ~10^4 Msun. This is consistent with the properties of the
cluster's brightest stars, which were resolved in the data for the first time.
Finally, a numerical analysis of the galaxy's stellar content yields a roughly
constant star formation rate of 1.3x10^-3 Msun/yr and mean metallicity of
[Fe/H] = -1.3 dex from 15 Gyr ago to the present.

Astrophysics