Status Report

Hubble Space Telescope Daily Report #2903 28 June 2001

By SpaceRef Editor

June 28, 2001

Filed under Hubble Space Telescope, Space Telescope Science Institute, US

HUBBLE SPACE TELESCOPE

DAILY REPORT #2903

PERIOD COVERED: 0000Z (UTC) 06/27/01 – 0000Z (UTC) 06/28/01

Daily Status Report as of 179/0000Z

1.0 OBSERVATIONS SCHEDULED AND ACCOMPLISHED:

1.1 Completed WF/PC-2 8146 (A Search for Binary L-Dwarfs)

The WF/PC-2 was used to search for close binaries amongst the
sample of 37 low-temperature L dwarfs, identified primarily in the course
of the DENIS and 2MASS near-infrared surveys. The observations completed
with no reported problems.

1.2 Completed Two Sets of WF/PC-2 8828 (Cycle 9 Supplemental Darks pt3/3)

The WF/PC-2 was used to obtain three dark frames every day to
provide data for monitoring and characterizing the evolution of hot
pixels. The proposal completed with no reported problems.

1.3 Completed WF/PC-2 8634 (Atmospheric Variability on Uranus and Neptune)

The WF/PC-2 was used to obtain snapshot observations of Uranus and
Neptune to monitor changes in their atmospheres on time scales of months to
years. Uranus is rapidly approaching equinox in 2007, with another 4
degrees of latitude in the northern hemisphere becoming visible every
year. Recent HST images during this unique epoch have revealed: {i}
strongly wavelength-dependent latitudinal structure, {ii} the presence of
numerous visible-wavelength cloud features in the northern hemisphere, and,
{iii} in the near-IR, discrete features northward of 25degrees N that have
the highest contrast ever seen for a Uranian cloud. Long-term ground-
based observations show seasonal brightness changes whose origins are not
well understood. Recent IR images of Neptune obtained using adaptive
optics on the Keck Telescope indicate that a new “Bright Companion” type of
feature has recently appeared in the southern hemisphere. Snapshot
observations of these two dynamic planets can supply context in which to
discern the nature of long-term changes in their latitudinal atmospheric
bands and to track the appearance, movement, and disappearance of discrete
albedo features. There were no reported problems.

1.4 Completed WF/PC-2 8632 (A UV Atlas of Nearby Galaxies)

The WF/PC-2 was used to perform a snapshot survey of local galaxies
at UV wavelengths with the F300W filter. The aim of the project is to
build a reference UV Atlas of normal galaxies, whose optical images are
well known, with the highest possible degree of information, covering all
the morphological types and luminosity classes. The proposal completed
normally.

1.5 Completed Four Sets of WF/PC-2 9044 (The Stellar Population of UGCA
292, An Extreme Low Metallicity Galaxy)

The WF/PC-2 was used to observe the third lowest metallicity galaxy
known, UGCA 292, that provides a unique opportunity to investigate the
evolutionary status of extremely metal–poor, gas–rich, star–forming
galaxies. UGCA 292 is sufficiently nearby, that it is possible to resolve
the stellar population with HST. These observations enable investigation
of the stellar population of this relatively unevolved galaxy and determine
if the low metallicity and high gas mass fraction are indicative of a newly
formed galaxy. The observations completed nominally.

1.6 Completed WF/PC-2 8601 (A Snapshot Survey of Probable Nearby Galaxies)

The WF/PC-2 was used to continue the very successful snapshot
survey in order to use the high spatial resolution of HST to determine
whether selected galaxies are nearby on the basis of resolution into stars,
and the magnitudes and colors of the brightest stars. There were no
reported problems.

1.7 Completed WF/PC-2 9133 (Imaging of Gravitational Lenses)

The WF/PC-2 was used to observe gravitational lenses that offer
unique opportunities to study cosmology, galactic structure, galaxy
evolution, quasar hosts and extinction. They are also the only sample of
galaxies selected on the basis of their mass rather than their luminosity
or surface brightness. While gravitational lenses can be discovered with
ground-based optical and radio observatories, converting them from
curiosities into scientific tools requires HST. There were no reported
anomalies.

2.0 FLIGHT OPERATIONS SUMMARY:

2.1 Guide Star Acquisitions:

Scheduled Acquisitions: 11

Successful: 11

Scheduled Re-acquisitions: 5

Successful: 5

2.2 FHST Updates:

Scheduled: 21

Successful: 21

2.3 Operations Notes:

The STIS instrument remains in safe mode.

Using ROP SR-1A, the SSR EDAC error counter was cleared once.