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