HST/WFPC-2 Observations of a Small Cluster of Galaxies in Ursa Major
Session 107 -- Galaxies: Morphology and Interactions
Display presentation, Thursday, 12, 1995, 9:20am - 6:30pm

## [107.13] HST/WFPC-2 Observations of a Small Cluster of Galaxies in Ursa Major

J.L.Sandoval, E.M.Malumuth (CSC/GSFC)

We present HST/WFPC-2 images of a previously unknown small cluster of galaxies in Ursa Major. These images were obtained as part of the GTO parallel program. In this program, WFPC-2 images are taken using the F606W (wide V) and F814W (WFPC-2 I) filters in parallel with GTO observations using other HST instruments. The WFPC-2 images, obtained in parallel with FGS observations of BD+67\deg552 on April 22, 1994, contain a number of galaxies between 3\arcsec \space and 8\arcsec \space in diameter as well as a multitude of other smaller galaxies.

The cluster is dominated by eight large spiral galaxies in an area smaller than one Wide Field Camera chip ($80\arcsec \times 80\arcsec$). We present V and I band photometry, V$-$I colors of each galaxy in the field, and V$-$I color gradients for the larger galaxies. The luminosity function and density morphology relationship is also discussed. Based on the luminosity function and linear diameter of the largest galaxies, we estimate the redshift of the cluster to be z$\sim$0.2 (H$_{\rm o}$=75 and q$_{\rm o}$=0).