CORRECTED Astro-2 Public Affairs Status Report #23 6:00 a.m. CST ( 11/5:22 MET), March 13, 1995 Spacelab Mission Operations Control Marshall Space Flight Center Huntsville, Ala. Scientists with the Wisconsin Ultraviolet Photo-Polarimeter Experiment (WUPPE) received surprising data from their telescope last night as the second Astro Observatory (Astro-2) mission continued aboard the Space Shuttle Endeavour. Astronomers for WUPPE were surprised to learn that the orientation (polarization) of ultraviolet radiation coming from Mars is due to the planet's soil composition, rather than elements in the Martian atmosphere. "As we looked at the data we received from our equipment onboard the Shuttle, we saw similarities between the polarization of ultraviolet light emitted by Mars and the polarization of ultraviolet light recorded during an earlier lunar observation," explained WUPPE scientist Dr. Geoff Fox. "We'll continue to examine our data to learn more about the composition of Martian soil." The WUPPE telescope also made observations to study the polarization of ultraviolet light between stars in the Large Magellanic Cloud for Guest Investigator Dr. Geoffrey Clayton. Supergiant stars were used as background lighting, allowing WUPPE and the Hopkins Ultraviolet Telescope (HUT) to observe dust particles between stars in this galaxy. WUPPE and HUT science teams expect to see differences in interstellar polarization between the Large Magellanic Cloud and our own Milky Way galaxy because the chemical elements found in the interstellar dust of these galaxies are so different. UIT will collect images of large fields in the Magellanic Clouds during this mission to study stellar mass and age distributions in the galaxy. HUT observed two Seyfert 1 galaxies in the constellation Ursa Major, the Big Dipper, last night NGC 3516 and NGC 4151. These galaxies, named for astrophysicist Carl Seyfert, are believed to be powered by supermassive black holes at their cores. Spectra of these galaxies show broad emission lines, indicating clouds of gas moving at thousands of miles per second, with the energy emitted covering a broad range of frequencies. HUT scientists are studying variations in the amount of ultraviolet light in these galaxies to learn more about the processes that affect their spectra. The Ultraviolet Imaging Telescope (UIT) also observed these galaxies to help astronomers understand more about the transfer of energy between the nuclei and surrounding regions. Mission Specialist John Grunsfeld pointed HUT at Venus, the planet that most resembles Earth in size, density and composition. Planetary probes have shown Venus to have an atmosphere largely composed of carbon dioxide, extremely high surface temperatures, constant high surface winds, and atmospheric pressure 90 times that of the Earth's. HUT scientists are searching the atmosphere of Venus for traces of argon, neon and helium. The presence of these gases in Venus' atmosphere are important indicators concerning the formation of the solar system. WUPPE observed Venus to learn more about the polarization properties of the atmosphere surrounding the planet and will use these data to understand more about the polarization of light from Jupiter during an upcoming Astro-2 observation. Grunsfeld also aligned HUT to observe two pulsating white dwarf stars last night. These two stars, one located in the constellation Hercules and another in Ursa Minor, are believed to be in a transitory stage in the evolution of extremely hot white dwarfs. Astronomers will use information from Astro-2 observations such as this one to learn more about the evolution of stars. Payload Commander Tammy Jernigan moved the Instrument Pointing System into position for Payload Specialist Sam Durrance to point UIT at celestial objects. The first object, galaxy NGC 4214, was imaged by UIT to be included in an atlas of spiral galaxies being created by Guest Investigator Dr. Wendy Freedman. When completed, this atlas will be available at no cost to the astronomy community through the on-line electronic facilities of the NASA/Infrared Processing and Analysis Center Extragalactic Database. A deep survey field, known as UGC 5675, was also imaged by UIT last night. UIT Principal Investigator Theodore Stecher will also use these images to learn more about the population of distant non-thermal sources, search for high redshift blue galaxies, determine galactic luminosities for faint magnitudes, identify distant clusters of star-forming galaxies, and obtain counts of galaxies down to faint ultraviolet magnitudes to complement similar data in visual and other spectral regions. UIT Guest Investigator Dr. Gregory Bothun will use images of this dark area of the sky to determine if UIT can detect very faint galaxies against a dark background and search for a bright near-ultraviolet component that may be responsible for extremely blue optical colors that have been observed in other galaxies with very low star-formation rates. During the next 12-hours, the STS-67 crew will point the HUT, UIT and WUPPE ultraviolet telescopes to the heavens to help scientists study molecular hydrogen in interstellar medium, observe the planet Venus, investigate interstellar shocks associated with supernova remnants, observe starburst clusters and a variable star. To follow the mission in progress, visit Astro-2's home page on the Internet World Wide Web: URL "http://astro-2.msfc.nasa.gov"