Note on Filters:
UGC 6151 is a Low Surface Brightness Galaxy which is at the center of the first deep survey field taken with UIT. The total exposure time was 1370 seconds out of a planned 2000 through the A1 filter.
NGC 4151 is a nearby Seyfert Galaxy which has a very bright nucleus. The galaxy has very faint outer spiral structure and tightly wound inner spiral structure. The outer spiral structure should be more prominent at UV wavelengths if star formation is occurring out there. The nucleus is relatively unobscured by dust and therefore should be easily detectable at UV wavelengths. Exposure time was 385 seconds.
M101 is a very actively star forming nearby galaxy. Astro-1 revealed it to have very extended structure in the Ultraviolet. Based on those observations, additional targets in the outside regions of M101 have been selected for this mission. Total exposure time was 1113 seconds through the A1 filter.
M4 is a classic globular cluster. The UIT observations are hoping to identify stars which are UV bright. These represent stars in advanced stages of stellar evolution in which the outer layers of the star are shed revealing a hotter star. It is thought that the numbers of these hot stars in advanced evolutionary stages is correlated with the mean metal abundance of the cluster. Total exposure time was 1600 seconds using the A1 and B5 filters
NGC 5236 or M83 is a prime galaxy for UV observations. It is currently forming stars at a very high rate and has been the host galaxy for 6 supernova that have occured since 1923. The overall angular size of M83 is about 11 arcminutes so the wide field nature of UIT will enable the entire galaxy to be imaged one exposure. Several exposures of M83 are planned during this mission. This one was 2000 seconds through the A1 and B5 filters.