Hubble Space Telescope Daily Report #2859 – 26 Apr 2001

HUBBLE SPACE TELESCOPE

DAILY REPORT #2859

PERIOD COVERED: 0000Z (UTC) 04/25/01 – 0000Z (UTC) 04/26/01

Daily Status Report as of 116/0000Z

1.0 OBSERVATIONS SCHEDULED AND ACCOMPLISHED:

1.1 Completed Two Sets of WF/PC-2 8816 (Cycle 9 UV Earthflats)

The WF/PC-2 was used to obtain sequences of Earth streak flats to
improve the quality of pipeline flat fields for the WFPC2 UV filter set and
in order to monitor flat field stability. There were no reported problems.

1.2 Completed Two Sets of 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.

1.3 Completed Three Sets of WF/PC-2 8827 (Cycle 9 Supplemental Darks pt2/3)

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 nominally.

1.4 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.

1.5 Completed Six 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.

1.6 Completed Five Sets of 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.

1.7 Completed Three Sets of FGS/1 8731 (A High Angular Resolution
Survey of the Most Massive Stars in the SMC)

Fine Guidance Sensor #1 was used to conduct high angular resolution
observations of some of the SMC’s hottest and most luminous objects by
conducting a comprehensive survey of nearly every spectral type in the
upper portion of the HR diagram. Binary or multiple star systems will be
detected down to an unprecedented level, more than one order of magnitude
better than possible with WFPC2. The targets selected include a
representative list of normal Main Sequence O-stars and their evolved
descendents, namely supergiants, hypergiants, LBVs, and WRs, many of which
have been previously observed by HST’s spectrometers for purposes of
cosmological calibrations. The observations completed, and no problems
were reported.

1.8 Completed WF/PC-2 8583 (Imaging Snapshots of Asteroids)

The WF/PC-2 was used to obtain images of the fifty largest main
belt asteroids that have favorable apparitions during cycle 9. The images
will be searched for companion bodies, as well as mineralogical variegation
on the resolved main bodies. There were no reported problems.

1.9 Completed STIS/CCD 9246 (POMS Test Proposal: Non-scripted Parallel
Proposal Continuation IV)

The Space Telescope Imaging Spectrograph (CCD) 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.

1.10 Completed WF/PC-2 8604 (Stellar Populations Across the Small
Magellanic Cloud (SMC) : History and Structure)

The WF/PC-2 was used to investigate the structure and evolutionary
history of the SMC by obtaining a series of 50 three-color snapshots of
selected SMC regions. With this polling of SMC field star properties, we
will produce color-magnitude diagrams in the U, V and I bands which will
reach V~23.5 in regions too crowded to be observed accurately from the
ground. The observations completed nominally.

1.11 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.

1.12 Completed 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.

1.13 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.

1.14 Completed WF/PC-2 8682 (A Snapshot Study of 0bservational Cosmology)

The WF/PC-2 was used to examine the observational constraints on
the cosmic star formation history that is currently among the most active
fields in observational cosmology. The most widely used tracer of the
co-moving volume-averaged star formation rate {SFR} is the UV luminosity
density, which early results found to peak at z~1- 2. The apparent
identification of the primary epoch of metal production and star formation
in the Universe led to intense theoretical and observational
interest. Nevertheless, and remarkably for such a fundamental observation,
little is known about the history of star formation in the Universe beyond
its global average. There were no reported anomalies.

1.15 Completed STIS/CCD/MA1 8566 (High Resolution UV/X-Ray Spectroscopy
of SMC X-1)

The Space Telescope Imaging Spectrograph (CCD and MA1) was used to
perform simultaneous observations of the X-ray pulsar SMC X-1 and its B0
companion SK160 with Chandra and ground-based optical telescopes. The
proposer will search for correlation between orbital phase and “bleaching”
of important P Cygni lines by X-ray photoionization, and will model the
simultaneous X-ray, ultraviolet, and optical continuum emission at
different phases of the superorbital period to measure changes in mass
accretion rate, disk structure, and disk size. The proposal completed with
no reported problems.

1.16 Completed WF/PC-2 8059 (POMS Test Proposal: Targeted Parallel
Archive Proposal)

The WF/PC-2 was used to observe the parallel opportunities
available in the neighborhood of bright galaxies are treated in a slightly
different way from the normal pure parallels. Local Group galaxies offer
the opportunity for a closer look at young stellar
populations. Narrow-band images in F656N can be used both to identify
young stars via their emission lines, and to map the gas distribution in
star-forming regions. The observations completed nominally.

1.17 Completed WF/PC-2 8602 (A Snapshot Survey of the Sites of Recent,
Nearby Supernovae)

The WF/PC-2 was used to conduct a snapshot survey in V and I of the
sites of the nearby SNe, which have precisely known positions, to obtain
high-resolution information on their local environment. The proposal
completed with no reported problems.

1.18 Completed STIS/CCD/MA1 8693 (Interstellar Boron & Oxygen
Abundances in the Cep OB2 Association: Probing)

The Space Telescope Imaging Spectrograph (CCD and MA1) was used to
investigate a specific nuclear process associated with core-collapse
supernovae that involves the inelastic scattering of neutrinos {produced as
a result of the core collapse} off of abundant nuclei in the outer layers
of the dying star. Two relatively low-abundance elements, boron and
fluorine, have been suggested to owe some uncertain fraction of their
cosmic abundances to this process. In the case of boron, the dominant
isotope is ^11B, and neutrinos interacting with ^12C can lead to its
synthesis. Fluorine-19 is the only stable F isotope and it can be produced
by neutrino scattering, removing a proton from ^20Ne. Competing processes
can also synthesyze these elements: cosmic-ray spallation reactions for B
and shell He-burning in AGB stars for F. In order to gauge the importance
of neutrino nucleosynthesis in the chemical evolution of the Galaxy, we
will determine interstellar B and O abundances in the gas associated with
the Cep OB2 association {using the B II 1362Angstrom and O I 1356Angstrom
lines}. These results will be combined with observations of interstellar F
I along the same lines-of-sight obtained with FUSE {fluorine can only be
compared directly to boron using interstellar lines and interstellar F is
only observable with FUSE}. The derived F/O and F/B ratios in Cep OB2 will
allow us to determine the relative importance of neutrino nucleosynthesis
to the origins of B and F. The proposal completed with no reported problems.

1.19 Completed STIS/CCD/MA1 8956 (Pre-SM Calibration)

The Space Telescope Imaging Spectrograph (CCD and MA1) was used in
an exercise to prepare for the SMOV-3B program. Prior to SMOV3B, one
iteration of proposal 8960 {Jitter Test} for WD 2126+734 will be
performed. Also one iteration of 8961 {End of BEA Test} for each new flux
standard {WD 2126+734, WD 0320-539, WD 0710+741, and WD 0214+568} needed to
completely cover all possible Bright Earth Avoidance {BEA} dates will be
exercised. Finally, one extra standard is added {WD 1407-475} to fill the
gap around June when WD 0214+568 is too close to the Sun. This iteration
of the proposal completed with no reported problems.

2.0 FLIGHT OPERATIONS SUMMARY:

2.1 Guide Star Acquisitions:

Scheduled Acquisitions: 12

Successful: 12

Scheduled Re-acquisitions: 4

Successful: 4

2.2 FHST Updates:

Scheduled: 28

Successful: 28

2.3 Operations Notes:

The SSR EDAC error counter was cleared three times per ROP SR-1A.

3.0 SIGNIFICANT FORTHCOMING EVENTS:

Continuation of normal science observations and calibrations.