Astro-2 Public Affairs Status Report #21 6:00 a.m. CST (10/5:22 MET), March 12, 1995 Spacelab Mission Operations Control Marshall Space Flight Center Huntsville, Ala. Researchers in orbit and on the ground worked together to make the first ever detailed observation of the moon in the far ultraviolet wavelengths last night, as the STS-67 Astro mission continues. Mission Specialist Wendy Lawrence maneuvered the orbiter into the required position, while Payload Commander Tammy Jernigan aligned the Instrument Pointing System (IPS) at the most difficult-to-acquire Astro-2 target, our moon. Payload Specialist Sam Durrance coordinated with science teams at Marshall Space Flight Center in Huntsville, Ala., to accurately point the Ultraviolet Imaging Telescope (UIT) at the moon. "The entire moon has never been imaged in the ultraviolet wavelengths, and we're looking forward to seeing these data," said UIT Guest Investigator Dr. Chan Na of Southwest Research Institute. No similar data have been obtained from either previous Shuttle missions, the Apollo program or Clementine, and there are no operating or planned spacecraft capable of imaging the whole moon at far ultraviolet wavelengths. UIT Guest Investigator Dr. Randy Gladstone, also of Southwest Research Institute, is using UIT to make far ultraviolet maps in order to learn more about the surface properties of the moon. "This lunar observation yielded 12 good, wide-field exposures of the moon," said Gladstone. The 70mm UIT film will developed and analyzed when Endeavour returns to Earth. UIT data gathered during Astro-2 will be used to test the hypothesis that the far ultraviolet surface brightness of an object without an atmosphere is a good indicator of the length of time that the surface has been exposed to space. These data will also help scientists understand future ultraviolet images of asteroids and other planetary satellites. The Wisconsin Ultraviolet Photo-Polarimeter Experiment (WUPPE) telescope observed the moon along with UIT last night to determine how well the WUPPE instrument could detect such features as dark seas or bright craters on the moon. Video from the WUPPE guide camera showed the instrument could clearly distinguish these lunar surface features. WUPPE scientists will now decide what observational goals they will set for the next lunar observation, later in the mission. Durrance also pointed the WUPPE telescope to a cool, giant star known as Alpha Orionis. This star, which pulsates about every five years, is approximately 14,000 times as radiant as our sun. WUPPE Principal Investigator Dr. Arthur Code will analyze the data from this Astro-2 observation to learn more about what effect these pulsations have on the envelope of gas and dust surrounding Alpha Orionis. Pilot William Gregory moved Endeavour into position, Mission Specialist John Grunsfeld aligned the IPS and Payload Specialist Ronald Parise again pointed the Hopkins Ultraviolet Telescope (HUT) at the quasar known as 1700+64. This quasar is the most distant object the HUT team is observing during Astro-2. HUT Principal Investigator Dr. Arthur Davidsen, of Johns Hopkins University, is using the quasar to provide background lighting in a search for helium in the intergalactic medium (the gas between galaxies). Helium is thought to be left over from the "Big Bang," a primordial fireball that many astronomers believe marked the birth of the universe about 10 to 20 billion years ago. The HUT telescope also observed a portion of the Cygnus Loop, a "middle-aged" supernova remnant, over night. Supernova remnants are visible evidence of the final cycle of stellar evolution and important sources of information for astronomers. The Cygnus Loop is of particular interest because it reveals details about the structure and velocity of shock waves from the explosion of a dying star) as they travel through the interstellar medium. HUT's spectrographic data will help scientists determine temperatures, densities and chemical compositions of the gases located in the Cygnus Loop. HUT team members say their recent observations of the Vela supernova remnant will allow scientists, for the first time, to measure the same supernova remnant shockwave from two angles. The Vela observations seem to show the same filament of expanding gas from the stellar explosion both edge on and face on. "If we can compare this filament in two positions, and verify that the models work for this object, we can generalize that and compare it to other data we've taken on the Cygnus Loop, the Vela supernova remnant and with other telescopes," said HUT Co-investigator Dr. Bill Blair. If successful, the comparison should give researchers a much better understanding of supernova remnants. Parise pointed WUPPE and HUT at a hot, massive star called 48 Librae, located in the constellation Libra. This star spins rapidly and has an outer layer that shows evidence of being peeled off by stellar winds. Previous observations of this star have suggested that its stellar winds are strongest near the star's equator because of its rapid rotation. WUPPE scientists are examining the polarization of this star's light to learn more about the scattering by electrons in the disk surrounding it. HUT scientists are trying to determine an accurate temperature for this star, search for stellar winds, and study absorption in the gas and dust between this star and nearby stellar objects. Jernigan and Durrance aligned WUPPE and HUT to look at a supergiant star, P Cygni. This star, which increases in brightness like a nova, has remained just visible to the naked eye for more than 100 years. Scientists believe it is not a true nova, rather a variable star surrounded by an expanding gaseous shell. WUPPE scientists are interested in P Cygni because it is ejecting mass at a colossal rate. As P Cygni scatters light, it produces a pronounced polarization which differs from theoretical models. Data from these Astro-2 observations will test refined theories and offer greater insight into the mysterious variability of P Cygni. Throughout the next 12 hours, HUT, WUPPE and UIT will be used to observe the planet Mars, look at young stellar populations in galaxies, examine supernova remnants and study a reflection nebula in a dark cloud. 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"