Daily Report #4740

HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

DAILY REPORT****** #4740

PERIOD COVERED: 5am November 18 - 5am November 19, 2008 (DOY
*************************** 323/1000z-324/1000z)

OBSERVATIONS SCHEDULED

WFPC2 10877

A Snapshot Survey of the Sites of Recent, Nearby Supernovae

During the past few years, robotic {or nearly robotic} searches for
supernovae {SNe}, most notably our Lick Observatory Supernova Search
{LOSS}, have found hundreds of SNe, many of them in quite nearby
galaxies {cz 4000 km/s}. Most of the objects were discovered before
maximum brightness, and have follow-up photometry and spectroscopy;
they include some of the best-studied SNe to date. We propose to
conduct a snapshot imaging survey of the sites of some of these nearby
objects, to obtain late-time photometry that {through the shape of the
light and color curves} will help reveal the origin of their lingering
energy. The images will also provide high-resolution information on
the local environments of SNe that are far superior to what we can
procure from the ground. For example, we will obtain color-color and
color-magnitude diagrams of stars in these SN sites, to determine the
SN progenitor masses and constraints on the reddening. Recovery of the
SNe in the new HST images will also allow us to actually pinpoint
their progenitor stars in cases where pre- explosion images exist in
the HST archive. This proposal is an extension of our successful Cycle
13 snapshot survey with ACS. It is complementary to our Cycle 15
archival proposal, which is a continuation of our long-standing
program to use existing HST images to glean information about SN
environments.

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.

FGS 11704

The Ages of Globular Clusters and the Population II Distance Scale
Globular clusters are the oldest objects in the universe whose age can
be accurately determined. The dominant error in globular cluster age
determinations is the uncertain Population II distance scale. We
propose to use FGS 1r to obtain parallaxes with an accuracy of 0.2
milliarcsecond for 9 main sequence stars with [Fe/H] -1.5. This will
determine the absolute magnitude of these stars with accuracies of
0.04 to 0.06mag. This data will be used to determine the distance to
24 metal-poor globular clusters using main sequence fitting. These
distances (with errors of 0.05 mag) will be used to determine the ages
of globular clusters using the luminosity of the subgiant branch as an
age indicator. This will yield absolute ages with an accuracy 5%,
about a factor of two improvement over current estimates. Coupled with
existing parallaxes for more metal-rich stars, we will be able to
accurately determine the age for globular clusters over a wide range
of metallicities in order to study the early formation history of the
Milky Way and provide an independent estimate of the age of the
universe.

The Hipparcos database contains only 1 star with [Fe/H] -1.4 and an
absolute magnitude error less than 0.18 mag which is suitable for use
in main sequence fitting. Previous attempts at main sequence fitting
to metal-poor globular clusters have had to rely on theoretical
calibrations of the color of the main sequence. Our HST parallax
program will remove this source of possible systematic error and yield
distances to metal-poor globular clusters which are significantly more
accurate than possible with the current parallax data. The HST
parallax data will have errors which are 10 times smaller than the
current parallax data. Using the HST parallaxes, we will obtain main
sequence fitting distances to 11 globular clusters which contain over
500 RR Lyrae stars. This will allow us to calibrate the absolute
magnitude of RR Lyrae stars, a commonly used Population II distance
indicator.

FGS 11901

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.

WFPC2 11113

Binaries in the Kuiper Belt: Probes of Solar System Formation and
Evolution

The discovery of binaries in the Kuiper Belt and related small body
populations is powering a revolutionary step forward in the study of
this remote region. Three quarters of the known binaries in the Kuiper
Belt have been discovered with HST, most by our snapshot surveys. The
statistics derived from this work are beginning to yield surprising
and unexpected results. We have found a strong concentration of
binaries among low-inclination Classicals, a possible size cutoff to
binaries among the Centaurs, an apparent preference for nearly equal
mass binaries, and a strong increase in the number of binaries at
small separations. We propose to continue this successful program in
Cycle 16; we expect to discover at least 13 new binary systems,
targeted to subgroups where these discoveries can have the greatest
impact.

WFPC2 11289

SL2S: The Strong Lensing Legacy Survey

Recent systematic surveys of strong galaxy-galaxy lenses {CLASS,
SLACS, GOODS, etc.} are producing spectacular results for galaxy
masses roughly below a transition mass M~10^13 Mo. The observed lens
properties and their evolution up to z~0.2, consistent with numerical
simulations, can be described by isothermal elliptical potentials. In
contrast, modeling of giant arcs in X-ray luminous clusters {halo
masses M ~10^13 Mo} favors NFW mass profiles, suggesting that dark
matter halos are not significantly affected by baryon cooling. Until
recently, lensing surveys were neither deep nor extended enough to
probe the intermediate mass density regime, which is fundamental for
understanding the assembly of structures. The CFHT Legacy Survey now
covers 125 square degrees, and thus offers a large reservoir of strong
lenses probing a large range of mass densities up to z~1. We have
extracted a list of 150 strong lenses using the most recent CFHTLS
data release via automated procedures. Following our first SNAPSHOT
proposal in cycle 15, we propose to continue the Hubble follow-up
targeting a larger list of 130 lensing candidates. These are
intermediate mass range candidates {between galaxies and clusters}
that are selected in the redshift range of 0.2-1 with no a priori
X-ray selection. The HST resolution is necessary for confirming the
lensing candidates, accurate modeling of the lenses, and probing the
total mass concentration in galaxy groups up to z~1 with the largest
unbiased sample available to date.

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.

FLIGHT OPERATIONS SUMMARY:

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

HSTARS:

11578 - NCC Safe During Recovery

Upon execution of circulator start up commanding (Ops Request 18364
step 23, Proc MNCSPNCI - NCS PCE On to Circulator On), a NSSC-1 Status
Buffer Message indicated that the circulator was shut down and the NCC
was safe at ~ GMT 323/13:28:46 due to exceeding the maximum circulator
current limit of 150 mAmps.

COMPLETED OPS REQUEST:

18364-1 - NCS Restart and Cooldown @ 323/1351z
18365-1 - *Contingency* Safe the NCC @ 323/1427z

COMPLETED OPS NOTES: (None)

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

FGS GSacq************** 10****************** 10
FGS REacq************** 04****************** 04
OBAD with Maneuver **** 28****************** 28

SIGNIFICANT EVENTS:

Flash Report NCC Restart Unsuccessful:

Upon execution of circulator start up commanding (Ops Request 18364),
a NSSC-1 Status Buffer Message indicated that the circulator was shut
down and the NCC was safe at ~ GMT 323/13:29 due to exceeding the
maximum circulator current limit of 150 mAmps.