In another study of cataclysmic variables, HUT observed EM Cygni, a dwarf nova which has no magnetic field. HUT scientists are using this quasar, located in the constellation Draco, to search the vast region of space between distant galaxies for evidence of helium left over from the primordial fireball that many scientists believe marked the birth of the universe. HUT Principal Investigator Dr. Arthur Davidsen is using the light from this extremely distant quasar as back lighting to shine through the intergalactic medium. Astronomers will use data from these Astro-2 observations to verify recent findings from the Hubble Space Telescope as well as measure the density and ionization state of the intergalactic helium. Parise also aligned HUT with two white dwarf stars for a study by HUT Guest Investigator Dr. David Finley.
White dwarfs are one of the extremely dense remnants of normal stars like the sun.
Those being studied with HUT are young and extremely hot stars. Finley is using these HUT observations to get very accurate measurements of the temperatures and surface gravity of white dwarf stars and determine the properties of hydrogen under conditions of extreme temperature and pressure. Another HUT investigation looked at a portion of a supernova remnant called the Cygnus Loop. Parise aimed HUT at Jupiter's moon Io again last night. A recent volcanic eruption on Io ejected material into Io's atmosphere and onto its surface.