Daily Report #4752

HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

DAILY REPORT****** #4752

PERIOD COVERED: 5am December 8 - 5am December 9, 2008 (DOY
*************************** 343/1000z-344/1000z)

OBSERVATIONS SCHEDULED

FGS 11943

Binaries at the Extremes of the H-R Diagram

We propose to use HST/Fine Guidance Sensor 1r to survey for binaries
among some of the most massive, least massive, and oldest stars in our
part of the Galaxy. FGS allows us to spatially resolve binary systems
that are too faint for ground-based, speckle or optical long baseline
interferometry, and too close to resolve with AO. We propose a
SNAP-style program of single orbit FGS TRANS mode observations of very
massive stars in the cluster NGC 3603, luminous blue variables, nearby
low mass main sequence stars, cool subdwarf stars, and white dwarfs.
These observations will help us to (1) identify systems suitable for
followup studies for mass determination, (2) study the role of
binaries in stellar birth and in advanced evolutionary states, (3)
explore the fundamental properties of stars near the main
sequence-brown dwarf boundary, (4) understand the role of binaries for
X-ray bright systems, (5) find binaries among ancient and nearby
subdwarf stars, and (6) help calibrate the white dwarf mass - radius
relation.

FGS/S/C 11945

Asteroseismology of Extrasolar Planet Host Stars

Detections of stellar oscillations, although a very demanding task in
terms of observing time, offers a return of more accurate knowledge
about the structure of stars than can be obtained in any other way. In
particular, detecting the 10-15 highest amplitude modes in solar-like
stars to signal-to-noise of just a few sigma each allows robust
constraints on the stellar density to 1%, and the stellar age to
within 5-10% of its main sequence lifetime. Ten day observing runs
using the FGS as a photometer on any of the 5 best transiting planet
systems would enable these asteroseismology returns. From more
precisely observed transit shapes than can be obtained from the ground
a completely independent constraint on stellar density to ~1% can be
obtained. The long observation sets required for asteroseismology also
provide an excellent opportunity of detecting transits from other
planets, e.g. hypothesized inner -orbit Hot Earths, should any exist.

WFPC2 11103

A Snapshot Survey of The Most Massive Clusters of Galaxies

We propose the continuation of our highly successful SNAPshot survey
of a sample of 125 very X-ray luminous clusters in the redshift range
0.3-0.7. As demonstrated by the 25 snapshots obtained so far in
Cycle14 and Cycle15 these systems frequently exhibit strong
gravitational lensing as well as spectacular examples of violent
galaxy interactions. The proposed observations will provide important
constraints on the cluster mass distributions, the physical nature of
galaxy-galaxy and galaxy-gas interactions in cluster cores, and a set
of optically bright, lensed galaxies for further 8-10m spectroscopy.
All of our primary science goals require only the detection and
characterization of high-surface-brightness features and are thus
achievable even at the reduced sensitivity of WFPC2. Because of their
high redshift and thus compact angular scale our target clusters are
less adversely affected by the smaller field of view of WFPC2 than
more nearby systems. Acknowledging the broad community interest in
this sample we waive our data rights for these observations. Due to a
clerical error at STScI our approved Cycle15 SNAP program was barred
from execution for 3 months and only 6 observations have been
performed to date - reinstating this SNAP at Cycle16 priority is of
paramount importance to reach meaningful statistics.

WFPC2 11302

WFPC2 CYCLE 16 Standard Darks - Part III

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 11793

WFPC2 Cycle 16 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.

WFPC2 11962

A New Supernova in the Antennae; Narrowing in on the Hubble Constant
and Dark Energy

A measurement of the Hubble constant to a precision of a few percent
would be a powerful aid to the investigation of the nature of dark
energy and a potent "end-to-end" test of the present cosmological
model. In Cycle 15 we constructed a new, streamlined distance ladder
utilizing high-quality type Ia supernova data and observations of
Cepheids with HST in the near-IR to minimize the dominant sources of
systematic uncertainty in past measurements of the Hubble constant and
reduce its total uncertainty to a little under 5%. Here we propose to
exploit this new route with a rare opportunity to begin reducing the
remaining uncertainty. SN 2007sr in the Antennae (NGC 4038/9) is the
rare SN Ia which is suitable for increasing the precision of small
calibration sample of SNe Ia. Even rarer is that it is close enough
that it's Cepheids are within range of observing with WFPC2 (and
NICMOS, should it return to life). But we need to act fast as the
window of long visibility and fixed orient runs from mid-early
December 2008 to early March 2009. We request 34 orbits with WFPC2 to
find the Cepheids in the SN host. We also request 16 orbits to observe
the Cepheids we find with Camera 2, F160W if NICMOS becomes available
by April 2009 . (If NICMOS does not return we would forgo these
observations and ask the TTRB to let us make them with our own WFC3-IR
allocation, though we much prefer the smaller pixel size of NIC2).

FLIGHT OPERATIONS SUMMARY:

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

HSTARS:

11603 - GSAcq (1,3,1) failed to RGA Hold (Gyro Control) @ 344/06:03.

Observations affected: Proposal 11945 Guide Star Acq Tests in
343SMS(FGS-1R K16) Reduction

COMPLETED OPS REQUEST:

18368-0 - Lower FGS1 K16 for Proposal 11945 guide star testing

COMPLETED OPS NOTES: (None)

SIGNIFICANT EVENTS:

FLASH Report: FGS-1R K16 K-factor changed.

The FGS-1R K16 K-factor was successfully changed by Ops Request #18368
at 344/00:55. The new value of 4982 was verified by TMDIAGs. The value
will be reset to the original value of 12,335 by SMS commanding at
2008.344/09:16:32