Astro-2 Public Affairs Status Report #19	
6:00 a.m. CST (9/5:22 MET), March 11, 1995	
Spacelab Mission Operations Control	
Marshall Space Flight Center	
Huntsville, Ala.	

   STS-67 crew members spent their ninth night aboard the Space
Shuttle Endeavour, pointing the three unique ultraviolet telescopes of
the second Astro Observatory (Astro-2) mission at celestial objects.
 
   Pilot William Gregory maneuvered the Endeavour into a position
where Mission Specialist John Grunsfeld and Payload Specialist Ronald
Parise could align the Wisconsin Ultraviolet Photo-Polarimeter
Experiment (WUPPE) with Nova Centauri 1995.  "The WUPPE instrument has
given us some spectacular spectral 'signatures' of the elements (such
as carbon, nitrogen or oxygen) that may be present in the atmosphere
following this very recent explosion," said Guest Investigator
Dr. Joni Johnson of the University of Wisconsin in Madison.  "We'll be
analyzing these data for quite some time, looking for clues about the
atmospheric composition, as well as the structure, of this new nova."

    Nova Centauri 1995, which occurred just two weeks before the
launch of Astro-2, is the result of a Red Giant, transferring material
to a compact white dwarf companion star.  After a period of time
(perhaps 1,000 years or more) the material which accreted onto this
white dwarf reached extremely high temperatures and pressure, causing
a thermonuclear explosion.  WUPPE scientists were excited to be able
to observe this rare new nova so soon after its beginning.

    Parise also pointed the WUPPE telescope to a massive star that is
known to have bright emission lines.  Scientists are studying this
type of star to learn more about the composition of material
surrounding the star and how it is effected by stellar winds.

   WUPPE scientists also got another look at a rare Wolf-Rayet star
overnight.  Wolf-Rayet stars are thought to represent one of the final
phases in the evolution of massive stars.  This type of massive star
has powerful, eroding stellar winds carrying material outward.  The
interaction between the star's light and this material causes the
radiation to be polarized (oriented in one particular direction)
rather than in all different directions.  The polarization of light
coming from this Wolf-Rayet star can tell astronomers something about
the properties of the stellar winds around it.

   Mission Specialist Wendy Lawrence maneuvered the orbiter to
different positions last night, allowing the WUPPE science team to
observe two galaxies in the Local Group.  Payload Commander Tammy
Jernigan operated the Instrument Pointing System, while Payload
Specialist Sam Durrance aimed the Astro-2 telescopes at the galaxies.
These two galaxies served as background lights for the study of
interstellar polarization, the direction that light travels between
stars.

    The Ultraviolet Imaging Telescope (UIT) imaged Holmberg 2 (a dwarf
galaxy) and a portion of the Andromeda spiral galaxy, M31, to help UIT
astronomers learn more about young stellar formations in galaxies.
One of the major science goals of the UIT is to map out our "twin
sister" galaxy, Andromeda (M31).  UIT also imaged a galaxy known as
NGC 3310, allowing investigators to study the design of spiral
galaxies and related structures, the nature of stellar populations,
and learn more about the material between stars associated with bars,
irregular, and anemic (poor in structure) galaxies.

   The Hopkins Ultraviolet Telescope (HUT) observed two Seyfert 1
galaxies, Markarian 279 and NGC 3516.  These targets are active
galaxies with bright, compact nuclei, radiating in wavelength ranges
from infrared to X- ray.  HUT Project Scientist Dr. Gerard Kriss
arranged simultaneous X-ray observations of NGC 3516 using the
Japanese X-ray satellite ASCA (the Advanced Satellite for Cosmology
and Astrophysics).  Astro-2 and ASCA will revisit NGC 3516 for another
observation in two days.  UIT scientists observed these galaxies to
better understand how energy is transferred between the nuclei and
surrounding regions.

   Parise pointed HUT at a dwarf nova called Z Camelopardalis (Z CAM).
This stellar system has two stars locked in a tight orbit around each
other, with an orbital period of seven hours.  The companion star to Z
CAM is a low mass star which transfers matter onto Z CAM, causing
outbursts of ultraviolet emissions.

    Parise aligned HUT with a portion of the supernova remnant Cygnus
Loop D.  HUT scientists are studying a very bright, radiative filament
on the western edge of the Cygnus Loop, to learn more about the shock
waves generated during the death of a star.  Astronomers will analyze
these HUT data to determine temperatures, densities, and chemical
compositions of the gaseous filaments in the interstellar medium.

   During the next 12 hours, HUT, UIT and WUPPE will be aimed at the
heavens to let Astro-2 astronomers observe interstellar shock waves in
supernova remnants, young stellar populations in galaxies, the
luminous cores of active galaxies, dust and gas between stars, and
electron scattering of single stars.

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"