Hubble Space Telescope Daily Report #2870 – 11 May 2001

HUBBLE SPACE TELESCOPE

DAILY REPORT #2870

PERIOD COVERED: 0000Z (UTC) 05/10/01 – 0000Z (UTC) 05/11/01

Daily Status Report as of 131/0000Z

1.0 OBSERVATIONS SCHEDULED AND ACCOMPLISHED:

1.1 Completed Two Sets of WF/PC-2 8581 (A Search For Low-Mass
Companions To Ultracool Dwarfs)

The WF/PC-2 was used to search for very low-mass {VLM} companions
to a complete sample of 120 late-M and L dwarfs, drawn mainly from the
2MASS and SDSS surveys. The primary goal is to determine the multiplicity
of M < 0.1 M_odot dwarfs. In particular, we aim to identify binary systems suitable for long-term astrometric monitoring and mass measurement, and systems with cool, sub-1000K companions. The proposal completed with no reported problems.

1.2 Completed Eleven Sets of STIS/CCD 9248 (Probing the Large Scale
Structure: Cosmic Shear Observations)

The Space Telescope Imaging Spectrograph (CCD) was used to measure
the distortion of light bundles from distant galaxies that probe the
statistical properties of the intervening inhomogeneous {dark} matter
distribution. Its tidal gravitational field distorts the observable image
shapes thereby causing a coherent ellipticity pattern {Cosmic Shear}. The
observations completed nominally.

1.3 Completed 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.

1.4 Completed STIS/CCD 8864 (CCD Dark Monitor-Part 2)

The Space Telescope Imaging Spectrograph (CCD) was used to monitor
the darks for the CCD. The proposal completed nominally.

1.5 Completed WF/PC-2 8723 (A Snapshot Survey of Galactic Globular
Clusters)

The WF/PC-2 was used to observe the crowded centers of globular
clusters {GCs} that heretofore have produced intriguing discoveries of new
phenomena, most of which are not understood theoretically. The
observations completed with no reported problems.

1.6 Completed STIS/CCD 8865 (Bias Monitor-Part 2)

The Space Telescope Imaging Spectrograph (CCD) was used to monitor
the bias in the 1×1, 1×2, 2×1, and 2×2 bin settings at gain=1, and 1×1 at
gain = 4, to build up high-S/N superbiases and track the evolution of hot
columns. The proposal completed with no anomalous activity.

1.7 Completed WF/PC-2 8702 (The Most Elusive Nuclei of LMC Planetary
Nebulae)

The WF/PC-2 was used to carry out a SNAPSHOT survey of the faintest
nuclei of planetary nebulae {PNe} in the LMC. This program will be a
crucial follow-on to a Cycle 8 SNAPSHOT of LMC Pne. In thisa case the plan
is to observe the faintest or most obscured nuclei to determine their
evolutionary state to an accuracy not possible in the Galaxy. These
faintest central stars are predicted to be among the most massive nuclei,
and owing to the typically advanced age of the surrounding nebulae, are the
most sensitive discriminants for validating the post-AGB evolution
timescales predicted by theory. The observations completed with no
reported problems.

1.8 Completed Two Sets of STIS/MA2 8843 (Cycle 9 MAMA Dark Measurements)

The Space Telescope Imaging Spectrograph (MA1) was used to perform
the routine monitoring of the MAMA detector dark noise. The proposal
completed nominally.

1.9 Completed WF/PC-2 8585 (Cosmological Parameters from Type Ia
Supernovae at High Redshift)

The WF/PC-2 was used to measure the cosmological parameters, Omega,
Lambda, and thus the curvature, Omega_k, using Type Ia supernovae {SNe Ia}
as calibrated standard candles. There were no reported problems.

1.10 Completed WF/PC-2 8712 (The Wind Accretion Wake In A Detached
Binary System)

The WF/PC-2 was used to observe RW Hya {= HD 117970}, the only
known detached binary system, where direct observational evidence for wind
accretion onto a white dwarf is found. UV
observations will enable the investigator to advance knowledge in a field
which has for long had to remain a theoretical subject. RW Hya is an
eclipsing system containing a mass-losing M-giant and a hot white dwarf on
circular orbits {370 days}. The observation completed with no reported
problems.

1.11 Completed WF/PC-2 9244 (POMS Test Proposal: WFII Parallel Archive
Proposal Continuation)

The WF/PC-2 was used to perform a generic target version of the
Archival Pure Parallel program. The program will be used to take parallel
images of random areas of the sky, following the recommendations of the
Parallels Working Group. The observations completed with no anomalous
activity.

1.12 Completed WF/PC-2 8677 (Extragalactic Novae: the Maximum Magnitude
– Rate of Decline Relation in NGC 4472)

The WF/PC-2 was used to accomplish two goals: {1} to provide the
first homogeneous observational constraints on theoretical models for novae
outbursts; and {2} to assess the reliability of novae as standard candles
by using WFPC2 to collect well sampled light curves for 20-50 novae in the
supergiant elliptical galaxy NGC 4472, the brightest galaxy within 30
Mpc. Both the length of the observing window and the temporal sampling of
the observations are specifically designed to ensure that the novae peak
magnitudes and decline rates are measured accurately. These data will be
used to construct the first `Maximum Magnitude versus Rate of Decline’
{MMRD} relation for a galaxy beyond the Local Group. This relation is not
only a potentially powerful standard candle, but its shape and dispersion
are directly linked to physical parameters which govern the physics of
novae outbursts such as the white dwarf mass, temperature and mass
accretion rate. The proposal completed with no reported problems.

1.13 Completed WF/PC-2 8599 (A Census of Nuclear Star Clusters in
Late-Type Spiral Galaxies)

The WF/PC-2 was used to conduct an I-band snapshot survey of a
well-defined sample of nearby, face-on spiral galaxies of type Scd or
later. The proposal completed nominally.

1.14 Completed WF/PC-2 8177 (Investigating Type Ia Supernovae and an
Accelerating Universe)

The WF/PC-2 was used to obtain rest frame U and B photometry for
four z~ 0.85 Supernova (SN) Ia. These observations will be coupled to
ground-based rest frame V photometry and spectra. These data, combined
with previous samples, will extend the D_L vs. z diagram for SN Ia to
z~0.85, and allow us to discriminate the redshift dependence of supernova
magnitudes in an accelerating Universe from that expected to result from
systematic effects such as age of the stellar population, chemical
evolution, a drift in the properties of dust, and weak gravitational
lensing. The proposal completed with no reported problems.

2.0 FLIGHT OPERATIONS SUMMARY:

2.1 Guide Star Acquisitions:

Scheduled Acquisitions: 7

Successful: 7

Scheduled Re-acquisitions: 9

Successful: 9

2.2 FHST Updates:

Scheduled: 15

Successful: 15

2.3 Operations Notes:

ROP DF-05A was utilized to modify the telemetry diagnostic usage,
restoring the MSS 1 and 2 Mag Field Squared values in slots 2 and 3. This
was done at 130/1406Z.

The SSR EDAC error counter was cleared at 130/2337Z, using ROP SR-1A.

3.0 SIGNIFICANT FORTHCOMING EVENTS:

Continuation of normal science observations and calibrations.