Daily Report #4779

HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

DAILY REPORT****** #4779

PERIOD COVERED: 5am January 27 - 5am January 28, 2009 (DOY
************************** 027/1000z-028/1000z)

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.

ACS/SBC 11566

Imaging Saturn's Equinoctal Auroras

Auroral emissions provide an indispensable diagnostic tool for the
energetic processes occurring in planetary magnetospheres. In 2009
Saturn will reach equinox for the first time since the advent of
high-sensitivity planetary ultraviolet (UV) auroral imaging, offering
a unique, transient opportunity to observe both polar auroral regions
simultaneously. The observations proposed here will not only provide
the best images to date of Saturn's northern auroras, they will
address three fundamental issues: (1) Are Saturn's auroras similar in
the north and south? This will reveal the nature of the processes that
cause the northern auroras, and verify the multipole nature of Saturns
internal magnetic field. (2) Is the location of the northern auroral
emission symmetric with to the south? This will indicate why the
southern auroral oval is displaced a few degrees toward midnight from
the spin pole. It will also reveal whether the oscillation observed in
the location of the southern auroral oval is similarly observed in the
north, illuminating the nature of near-planetary period oscillations
observed throughout the magnetosphere and potentially providing a
value for the elusive rotation period of the deep interior. (3) What
is the influence of equinox on the magnetosphere? The unique
orientation of the planetary spin axis at equinox will reveal whether
the auroras are influenced by the direction of the interplanetary
magnetic field, and whether the Sun's effect on Saturn's magnetosphere
changes throughout the planet's seasons. The Hubble Space Telescope is
the only instrument capable of providing global instantaneous coverage
of Saturn's UV auroras, and since Saturn's orbital period is ~30
years, Cycle 17 is the only opportunity to make these observations.

FGS 11943/11944

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
follow up 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.

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.


FLIGHT OPERATIONS SUMMARY:

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

HSTARS:

11650 - GSAcq (1,2,2) scheduled from 027/12:44:20 - 027/12:51:27
failed at 12:48:20 due to QF1STOPF and QSTOP flags on FGS-1.

Observations affected: WFPC 38 - 41, Proposal# 10877.

COMPLETED OPS REQUEST:

18394-3 - Uplink new FHST Alignments

COMPLETED OPS NOTES: (None)

************************* SCHEDULED***** SUCCESSFUL
FGS GSacq*************** 12****************** 11
FGS REacq*************** 00****************** 00
OBAD with Maneuver ***** 24****************** 24

SIGNIFICANT EVENTS:

Flash Reports:

Ops Request 18394 was successfully executed approximately 027/13:55 -
13:52 to update the T2G Database for the FHST Alignments.