Hubble Space Telescope Daily Report #2976 – 15 Oct 2001

HUBBLE SPACE TELESCOPE

DAILY REPORT #2976

PERIOD COVERED: 0000Z (UTC) 10/12/01 – 0000Z (UTC) 10/15/01

Daily Status Report as of 288/0000Z

1.0 OBSERVATIONS SCHEDULED AND ACCOMPLISHED:

1.1 Completed Six Sets of STIS/CCD 8901 (Dark Monitor-Part 1)

The Space Telescope Imaging Spectrograph (CCD) was used to monitor
the darks. There was no anomalous activity.

1.2 Completed Seven Sets of WF/PC-2 8936 (Cycle 10 Supplemental Darks
Pt1/3)

The WF/PC-2 was used to perform a dark calibration program that
obtains three dark frames every day to provide data for monitoring and
characterizing the evolution of hot pixels. As described in HSTAR 8367 and
2.1, the acquisition for the sixth and seventh iterations of this proposal
failed, the take data flag remained down, and observations were
lost. Otherwise, the proposal completed with no other reported problems.

1.3 Completed STIS/CCD/MA2 8673 (The Properties of Ly-Alpha Absorbers
at Redshifts Between 0.9HST)

The Space Telescope Imaging Spectrograph (CCD and MA2) was used
obtain new Echelle resolution spectra of three bright quasars which, when
combined with archived and scheduled observations, will be used to
characterize the properties of Ly-Alpha absorbers in the redshift range
0.9

1.4 Completed Eighteen 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. As described in HSTAR 8367 and 2.1, the
acquisition for the eleventh iteration of this proposal failed, the take
data flag remained down, and observations were lost. Otherwise, the
observations completed with no further anomalous activity.

1.5 Completed WF/PC-2 9249 (POMS Test Proposal: WFII Backup Parallel
Archive Proposal II)

The WF/PC-2 was used to execute a POMS test proposal designed to
simulate scientific plans. The proposal completed with no reported problems.

1.6 Completed STIS/CCD/MA2 9048 (Boron Constraints on Slow Mixing in
Low Mass Stars)

The Space Telescope Imaging Spectrograph (CCD and MA2) was used to
observe the atomic and nuclear characteristics of the light elements Li, Be
and B, that make their photospheric abundances ideal tracers of internal
physical processes in stars. Both Li and Be have been heavily utilized to
this end since their diminished abundances are a direct result of the
extent of internal slow mixing between surface and interior layers, as has
been shown with ground-based data. Boron provides a fresh and special
probe because it survives to greater depths inside stars than does Li or
Be, and can thus uniquely reveal the depth of mixing. It is proposed to
observe B in stars with very large depletions of Li and Be, i.e. stars
which have been the most seriously affected by mixing. No problems occurred.

1.7 Completed Two Sets of STIS/CCD/MA2 8590 (UV Imaging and
Spectroscopy of Luminous Blue Compact Galaxies from z=0 to z=1)

The Space Telescope Imaging Spectrograph (CCD and MA2) was used to
observe two well-defined samples of low-mass starburst galaxies, one in the
local universe {z<0.1} and another at intermediate redshifts {0.2 < z < 0.7}. Both samples show optical sizes, morphologies, emission line widths, and luminosities comparable to those of LBGs at z=3, and are therefore probably the best local analogs and testbeds for further study of LBGs. Our main goals are to: {1} explore the morphologies, surface brightness distributions, and half-light radii of nearby starforming galaxies in the FUV, near Ly-alpha; {2} search for systematic differences among UV, optical, and near-IR morphologies and structural parameters; {3} investigate the intrinsic emission and absorption spectra near Ly-alpha of starbursting dwarf galaxies, with special attention to Ly- alpha profiles and interstellar and stellar photospheric absorption from Si II, O I, C II, Si IV, and C IV; {4} measure their FUV-optical colors and dust extinction properties; and {5} test the hypothesis that low-mass starbursts are the local counterparts of LBGs. The observation completed normally.

1.8 Completed Two Sets of STIS/CCD 9136 (T Tauri Star Coronagraphic
Survey: A PMS Protoplanetary Disk Census)

The Space Telescope Imaging Spectrograph (CCD) was used to observe
pre-main sequence solar-mass stars, the T Tauri stars that Millimeter and
IR studies suggest at least 50 percent have circumstellar disks similar to
the disk from which our planetary system formed. High spatial resolution,
high dynamic range imaging of such systems will map the spatial
distribution of material around the star, constraining the disk sizes and
inclinations, and provide a first assessment of when structure in the disk,
such as cleared central zones and annuli, which has been linked to planet
formation, develops. All observations completed without incident.

1.9 Completed WF/PC-2 9155 (The Cepheid Distance to NGC 1637: A Direct
Comparison with the EPM Distance to SN 1999em)

The WF/PC-2 was used to directly compare distances estimated by two
primary extragalactic distance indicators. T he appearance of supernova
1999em, a bright, extremely well- observed type II plateau event in the
nearby SBc galaxy NGC 1637 offers the best chance to test the consistency
of the Expanding Photosphere Method {EPM} of supernova distance
determination with that derived from Cepheid variable stars. Although EPM
distances have been measured to 18 type II supernovae out to 180 Mpc and
used to determine Hubble’s constant independent of the Cepheid distance,
there have never been any measurements of Cepheids in a galaxy that has
hosted a normal type II-P supernova, the classic variety of core-collapse
event to which EPM-derived distances are most robust. The proposal
completed nominally.

1.10 Completed Seven Sets of STIS/CCD 9285 (POMS Test Proposal: STIS
Non-scripted Parallel Proposal Continuation III)

The Space Telescope Imaging Spectrograph (CCD) was used to make low
galactic latitude, non-scripted parallel observations as part of a POMS
test proposal. The observations were completed as planned, and no
anomalies were reported.

1.11 Completed WF/PC-2/STIS/CCD 9258 (Observatory Focus Monitor)

The WF/PC-2 and the Space Telescope Imaging Spectrograph (CCD) were
used to more accurately define the HST focus. The HST focus drifts slowly
and shows evidence of undergoing slips of a few microns at random
times. The rate of the WF/PC-2 monitoring program is insufficient to track
and/or understand OTA behavior in order to request timely and appropriate
Secondary Mirror corrections. There were no reported problems.

1.12 Completed WF/PC-2 9069 (Proper Motions in Extragalactic Optical Jets)

The WF/PC-2 was used to observe the flow velocity of extragalactic
jets which is a crucial missing parameter in our understanding of these
objects. We would like to build on our successful HST proper motion
measurements in M87, and propose similar measurements in four other optical
jets. The proposal completed with no reported problems.

1.13 Completed Three Sets of STIS/CCD 8903 (Bias Monitor – Part 1)

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. There were no problems.

1.14 Completed Three Sets of STIS/CCD 9066 (Closing in on the Hydrogen
Reionization Edge of the Universe)

The Space Telescope Imaging Spectrograph (CCD) was used in parallel
constrain the Hydrogen reionization edge in emission that marks the
transition from a neutral to a fully ionized IGM at a predicted
redshifts. The proposal completed uneventfully.

1.15 Completed FGS/1 9227 (Observations of Astrophysically Important
Visual Binaries)

Fine Guidance Sensor #1 was used to perform observations of three
visual binary stars that will ultimately yield fundamental astrophysical
results, once their orbits and masses are determined. The targets are the
following: {1} Procyon {P=41 yr}, for which our first WF/PC-2 images
yielded an extremely accurate angular separation of the bright F star and
its very faint white-dwarf companion. Combined with ground-based
astrometry of the bright star, our observation significantly revised
downward the derived masses, and brought Procyon A into excellent agreement
with theoretical evolutionary tracks for the first time. The mass of
Procyon B, however, implies a completely unexpected chemical composition
for the white dwarf, and now poses a sharp evolutionary puzzle. With the
continued monitoring proposed here, we will obtain masses to an accuracy of
better than one percent, providing a test bed for theories of Sun-like
stars and white dwarfs. {2} G 107-70, a close double white dwarf {P=19 yr}
that promises to add two accurate masses to the tiny handful of white-dwarf
masses that are directly known from dynamical measurements. {3} Mu Cas
{P=21 yr}, a famous metal-deficient G dwarf for which accurate masses will
lead to the stars’ helium contents, with cosmological implications. No
problems were encountered for these observations.

1.16 Completed WF/PC-2 9042 (An Archive To Detect The Progenitors Of
Massive, Core-Collapse Supernovae)

The WF/PC-2 was used to search for supernovae which have massive
star progenitors. The already extensive HST archive and high-resolution
ground-based images of galaxies within ~20 Mpc enables us to resolve and
quantify their individual bright stellar content. As massive, evolved
stars are the most luminous single objects in a galaxy, the progenitors of
core-collapse supernovae should be directly detectable on pre-explosion
images. One Type II progenitor has been observed this year, and the
investigators have proposed a short, companion WFPC2 proposal to confirm
this candidate and identify a second. The observations completed nominally.

1.17 Completed Two Sets of STIS/CCD/MA1 8625 (The Metallicity of Gas in
the Local Universe: Beyond the Milky Way)

The Space Telescope Imaging Spectrograph (CCD and MA1) was used to
obtain spectra of three QSO/AGN which lie behind nearby galaxies in order
to measure the metallicity of the interstellar gas at the present epoch
beyond the local group. As described in HSTAR 8367 and 2.1, the
acquisition for the second iteration of this proposal failed, the take data
flag remained down, and observations were lost. Otherwise, the proposal
completed with no other reported anomalies.

1.18 Completed STIS/CCD/MA1 9241 (The Disk and Wind of HD 104237)

The Space Telescope Imaging Spectrograph (CCD and MA1) was used to
perform GTO studies of intermediate-mass stars that have revealed
circumstellar disks and associated nebulosities in 44% of our sample. The
largest-scale nebulosity is seen in those systems with emission in the
unidentified infrared bands, which have been interpreted as being
associated with C-H stretch and bend modes in small organic grains. This
hypothesis will be tested with coronagraphic observations of the nearby
Herbig Ae star, HD 104237. All observations completed normally.

1.19 Completed Two Sets of FGS/1 9034 (The Masses and Luminosities of
Population II Stars)

Fine Guidance Sensor #1 was used to observe the mass-luminosity
relation {MLR} of Population II stars of which very little is currently
known. With the advent of the Hipparcos Catalogue, improved distances to
many spectroscopic binaries known to be Pop II systems are now
available. After surveying the literature and making reasonable estimates
of the secondary masses, we find 13 systems whose minimum separation should
be larger than the resolution limit of FGS #1. The observations completed
nominally.

1.20 Completed WF/PC-2 9267 (Supernova Search)

The WF/PC-2 was used to search for high-redshift supernovae in
GO-observed fields, taking advantage of good first-epoch observations and
of the scheduling opportunities available because STIS is not currently
observing. No anomalous activity was reported.

1.21 Completed Four Sets of WF/PC-2 8941 (Cycle 10 UV Earthflats)

The WF/PC-2 was used to monitor flat field stability by obtaining
sequences of earth streak flats to improve the quality of pipeline flat
fields for the WFPC2 UV filter set. The proposal had no problems.

1.22 Completed FGS/1 9170 (The Post-CE Status of the Massive WD Binary
LB11146)

Fine Guidance Sensor #1 was used to perform analyses of the
spectrum of LB11146 that was discovered to be a binary system composed of
magnetic/nonmagnetic white dwarfs each having a mass estimated to be ~0.9
M_solar, making it the only known double degenerate system with a combined
mass exceeding the Chandrasekhar limit. No errors were reported

1.23 Completed STIS/CCD 9284 (POMS Test Proposal: STIS Non-Scripted
Parallel Proposal Continuation IV)

The Space Telescope Imaging Spectrograph (CCD) was used in the
parallel mode to make some low galactic latitude archive observations. The
observations were executed as scheduled, and no anomalies were noted.

1.24 Completed WF/PC-2 9045 (The Relationship Between Radio Luminosity
and Radio-Loud AGN Host Galaxy Properties)

The WF/PC-2 was used to determine the relationship between the
properties of the host galaxies of radio-loud AGN and their radio
luminosities. Previous studies in this area with the HST have concentrated
on the 3C sample which shows a tight correlation between luminosity and
redshift, such that evolutionary effects cannot be distinguished from those
depending upon radio luminosity. Our sample of 46 radio galaxies at z ~
0.5 comes from four complete, low-frequency-selected samples of radio
sources with differing flux limits. Thus the total sample spans an
unprecedented three orders of magnitude in radio luminosity at a fixed
redshift interval. The proposal completed with no reported problems.

1.25 Completed STIS/CCD/MA2 8651 (UV Spectroscopy in the Magellanic
Bridge: A Typical QSO Absorption Line System?)

The Space Telescope Imaging Spectrograph (CCD and MA2) was used to
perform echelle UV absorption line spectroscopy through the Magellanic
Bridge {near the SMC} to probe the temperature, ionization, and kinematic
structure in a metal- poor environment like those observed in the early
universe. The sightline toward the QSO B0312-770 is especially interesting
because of the proximity of the absorber and the radio loud background
source. The observations completed nominally.

1.26 Completed STIS/CCD 8669 (Merger-Driven Evolution Of Galactic
Nuclei: Observations Of The Toomre Sequence)

The Space Telescope Imaging Spectrograph (CCD) was used to observe
galaxy mergers that are believed responsible for triggering starburst and
AGN activity in galaxies, and even perhaps transforming spiral galaxies
into ellipticals. The proposal completed nominally.

1.27 Completed WF/PC-2 9057 (Host Galaxies of Obscured QSOs Identified
by 2MASS)

The WF/PC-2 was used to perform a snapshot survey of red QSOs
discovered in The Two Micron All Sky Survey {2MASS} to investigate the
detailed properties of their host galaxies. This large, possibly dominant,
population of QSOs in the local universe has been previously overlooked
because reddening by {intrinsic} obscuration along our line of sight causes
their colors to be too red for identification by traditional “UV- excess”
techniques. Their near-IR colors are similar to PG- type {UV-excess} QSOs,
but it is far from certain whether they are indeed from the same parent
population or represent a completely new class of QSO. There were no
reported problems.

1.28 Completed STIS/CCD 9143 (Spectrophotometry of Nearby Seyfert 2
Nuclei: Can We Eliminate the Seyfert 2 Class?)

The Space Telescope Imaging Spectrograph (CCD) was used to
investigate Seyfert 2s that are distinguished by the absence of the broad
emission lines characteristic of Seyfert 1s and more luminous QSOs. Are
Seyfert 2s fundamentally different from Seyfert 1s and their brighter
cousins? Or is the broad emission line region in Seyfert 2s simply
suppressed by obscuring material as postulated by the unification
model? If the latter model is correct, the weak broad emission lines in
the Seyfert 2s may simply be overwhelmed by starlight from the
circumnuclear region, particularly in the case of recent star
formation. It is proposed to determine if all Seyfert 2s have {weak} broad
emission line regions by obtaining long-slit STIS spectroscopy for a
well-defined sample of 20 Seyfert 2s {3 archival, 17 new}. The
observations completed with no anomalous activity.

1.29 Completed STIS/CCD 9176 (LMC Eclipsing Binaries with Cepheid
Components: The Key to the Extragalactic Distance Scale)

The Space Telescope Imaging Spectrograph (CCD) was used to
determine the distance to the LMC and to observe the Cepheid P-L that form
the backbone of the Cosmic Distance Scale and the determination of
H_degrees. Unfortunately, in spite of concerted efforts of many
investigators, the zero point of the Cepheid P-L law and the LMC distance
remain controversial and uncertain to ~10-15, using eclipsing binaries
{EBs} as “standard candles” to include two recently discovered LMC
eclipsing binaries {EBs} with Cepheid components. These observations of
these extraordinary systems hold the key to determining simultaneously the
Cepheid P-L zero point and the LMC distance, and to provide a direct test
of the Baade-Wesselink parallax method. There were no reported problems.

2.0 FLIGHT OPERATIONS SUMMARY:

2.1 Guide Star Acquisitions:

Scheduled Acquisitions: 27

Successful: 26

The acquisition scheduled for 287/005807Z failed when the search
radius limit was exceeded. A subsequent FHST map showed relatively small
errors. HSTAR 8367 was written. The proposals detailed in 1.2, 1.4, and
1.17 were affected.

Scheduled Re-acquisitions: 15

Successful: 15

2.2 FHST Updates:

Scheduled: 66

Successful: 66

2.3 Operations Notes:

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

Using ROP DF-18A, the engineering status buffer limits were
adjusted three times.

Per ROP DF-01A, an HST table dump was performed at 285/1526Z.

HSTAR 8366 documents an anomalous high condition for the high gain
antenna x-axis gimbal position for one telemetry sample at
286/171041Z. The commanded value was 86.0 degrees; the anomalous value,
87.6141 degrees. The gimbal was not splining at the time. The previous
and following splines were nominal.

ROP IC-2 was used to turn SSA #1 on and off for the interval
286/1852Z through 286/1923Z and SSA #2 from 288/0834Z through 288/0845Z.

A TTR was written when there was a required re-transmit at
287/1800Z during a NSSC-1 load. Accordingly, at 287/1806Z, per ROP NS-5,
SI C&DH errors were reset.

The engineering status buffer was dumped and cleared at 288/0242Z
as directed by ROP DF-18A.

A TTR was generated for a four-minute loss of engineering data
starting at 288/0356Z as the result of a negative acquisition after a Mode
1 GCMR.

3.0 SIGNIFICANT FORTHCOMING EVENTS:

Continuation of normal science observations and calibrations.