Daily Report #4444

Notice: Due to the conversion of some ACS WFC or HRC observations into
WFPC2, or NICMOS observations after the loss of ACS CCD science
capability in January, there may be an occasional discrepancy between
a proposal's listed (and correct) instrument usage and the abstract
that follows it.


HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

DAILY REPORT**** # 4444

PERIOD COVERED: UT September 10, 2007 (DOY 253)

OBSERVATIONS SCHEDULED

ACS/SBC 10840

The FUV fluxes of Tauri stars in the Taurus molecular cloud

Present and forthcoming ground-based and space surveys of the T Tauri
stars in the Taurus molecular cloud will provide information from high
energy stellar and accretion radiation to low energy solid state and
molecular emission from the disk, making those stars perfect
laboratories to carry out self-consistent studies of disk physics and
evolution. We propose to complete this wealth of information by
obtaining ACS/FUV spectra for a significant sample of Taurus T Tauri
stars, covering a range of accretion properties and dust evolutionary
stages. FUV fluxes carry ~ 10 - 100 more energy than X-rays into these
disks and are thus crucial gas heating agents and key to disk
dispersal by photoevaporation. These observations are a pre-requisite
to interpret observations with Spitzer, SOFIA, Herschel, and ALMA, and
will become one of the important legacies of HST to the star formation
community.

WFPC2 11024

WFPC2 CYCLE 15 INTERNAL MONITOR

This calibration proposal is the Cycle 15 routine internal monitor for
WFPC2, to be run weekly to monitor the health of the cameras. A
variety of internal exposures are obtained in order to provide a
monitor of the integrity of the CCD camera electronics in both bays
{both gain 7 and gain 15 -- to test stability of gains and bias
levels}, a test for quantum efficiency in the CCDs, and a monitor for
possible buildup of contaminants on the CCD windows. These also
provide raw data for generating annual super-bias reference files for
the calibration pipeline.

FGS 11212

Filling the Period Gap for Massive Binaries

The current census of binaries among the massive O-type stars is
seriously incomplete for systems in the period range from years to
millennia because the radial velocity variations are too small and the
angular separations too close for easy detection. Here we propose to
discover binaries in this observational gap through a Faint Guidance
Sensor SNAP survey of relatively bright targets listed in the Galactic
O Star Catalog. Our primary goal is to determine the binary frequency
among those in the cluster/association, field, and runaway groups. The
results will help us assess the role of binaries in massive star
formation and in the processes that lead to the ejection of massive
stars from their natal clusters. The program will also lead to the
identification of new, close binaries that will be targets of long
term spectroscopic and high angular resolution observations to
determine their masses and distances. The results will also be
important for the interpretation of the spectra of suspected and newly
identified binary and multiple systems.

NIC1 11057

Cycle 15 NICMOS dark current, shading profile, and read noise
monitoring program

The purpose of this proposal is to monitor the dark current, read
noise, and shading profile for all three NICMOS detectors throughout
the duration of Cycle 15. This proposal is a slightly modified version
of proposal 10380 of cycle 13 and 9993 of cycle12 and is the same as
Cycle 14. that we cut down some exposure time to make the observation
fit within 24 orbits.

NIC1/NIC2/NIC3 8794

NICMOS Post-SAA calibration - CR Persistence Part 5

A new procedure proposed to alleviate the CR-persistence problem of
NICMOS. Dark frames will be obtained immediately upon exiting the SAA
contour 23, and every time a NICMOS exposure is scheduled within 50
minutes of coming out of the SAA. The darks will be obtained in
parallel in all three NICMOS Cameras. The POST-SAA darks will be non-
standard reference files available to users with a USEAFTER date/time
mark. The keyword 'USEAFTER=date/time' will also be added to the
header of each POST-SAA DARK frame. The keyword must be populated with
the time, in addition to the date, because HST crosses the SAA ~8
times per day so each POST-SAA DARK will need to have the appropriate
time specified, for users to identify the ones they need. Both the raw
and processed images will be archived as POST-SAA DARKs. Generally we
expect that all NICMOS science/calibration observations started within
50 minutes of leaving an SAA will need such maps to remove the CR
persistence from the science images. Each observation will need its
own CRMAP, as different SAA passages leave different imprints on the
NICMOS detectors.

NIC2 11152

Probing the compact dust disk of a nearby Classical T Tauri Star

BP Psc is a high Galactic latitude {b = -57}, bright, IRAS source that
generally has been classified as a T Tauri star but little studied to
date. We have carried out a multiwavelength ground-based study of this
object and find that it is most likely a ~10 Myr classical T Tauri
star surrounded by a gas and dust disk, and less than 100 pc from
Earth, making it one of the oldest and closest such stars known.
Near-IR AO images and IR photometry show it is surrounded by an
compact {0.2"}, almost-edge-on, optically thick disk of dust with a
wide range of temperatures. We propose a multiwavelength polarimetric
study of the compact disk to support quantitative modeling to recover
disk and dust parameters. We also propose coronagraphic imaging to
search for larger-scale dust structures invisible in ground-based
images, and narrowband imaging of an outflow jet and associated
Herbig- Haro objects to study their structure and determine a
kinematic distance of the system. A massive compact disk surrounding
an isolated 10 Myr star is a unique environment for planet formation,
and its proximity to Earth allows HST to study it in detail.

WFPC2 11023

WFPC2 CYCLE 15 Standard Darks - part 1

This dark calibration program obtains dark frames every week in order
to provide data for the ongoing calibration of the CCD dark current
rate, and to monitor and characterize the evolution of hot pixels.
Over an extended period these data will also provide a monitor of
radiation damage to the CCDs.

WFPC2 11081

RR Lyrae stars in M31 Globular Clusters: How did the M31 Spiral Galaxy
Form?

The pulsation properties of the RR Lyrae stars in the globular
clusters of the Andromeda galaxy {M31} have the potential to provide
essential insight on the first epoch of the galaxy formation and to
trace the merging episodes that led to the assembly of M31. Their mean
periods along with the cluster metallicities can provide an
independent estimate of the M31 cluster ages and, in turn, of the time
scale of the M31 halo formation, by comparison with their Milky Way
counterparts. We will observe RR Lyrae stars in 6 appropriately
selected globular clusters of M31 using WFPC2 to derive periods, light
curves, and physical parameters of these eyewitnesses of the first
epochs of the M31 formation.

FLIGHT OPERATIONS SUMMARY:

Significant Spacecraft Anomalies: (The following are preliminary
reports of potential non-nominal performance that will be
investigated.)

HSTARS:

10989 - REAcq (2,1,1) failed to RGA Hold (Gyro Control)

At 253/11:29:25 REAcq (2,1,1) scheduled from 253/11:26:13 - 11:33:48
failed to RGA Hold (Gyro Control) after receiving a QSTOP flag on FGS
2. Mnemonics QF2STOPF, QSTOP, QF1SSDIF and QF2SSDIF all flagged out
due to this failure.

OBAD #1: V1 -996.75, V2 -1468.06, V3 570.40, RSS 1863.89
OBAD #2: V1 6.61, V2 0.56, V3 -4.70, RSS 8.13
OBAD MAP: Not scheduled

10990 - GSAcq (2,1,1) failed to RGA Hold (Gyro Control)

GSAcq (2,1,1) failed to RGA Hold due to QSTOP flag on FGS 2. Mnemonics
QF2STOPF, QSTOP, QF1SSDIF and QF2SSDIF all flagged out due to this
failure. No 486 ESB messages were received. The star pair used in this
acquisition is the same pair as used in HSTAR 10989.

OBAD #1: Unavailable due to LOS
OBAD #2: V1 7.23, V2 0.81, V3 -0.12, RSS 7.28
OBAD MAP: V1 -4.81, V2 1.46, V3 3.62, RSS 6.20

COMPLETED OPS REQUEST: (None)

COMPLETED OPS NOTES: (None)

*********************** SCHEDULED***** SUCCESSFUL

FGS GSacq************** 06***************** 05
FGS REacq************** 09***************** 08
OBAD with Maneuver **** 30***************** 30

SIGNIFICANT EVENTS: (None)