Daily Report #4793

HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

DAILY REPORT****** #4793

PERIOD COVERED: 5am February 17 - 5am February 18, 2009 (DOY
*************************** 048/1000z-049/1000z)

OBSERVATIONS SCHEDULED

ACS/SBC 11984

Observing Saturn's High Latitude Polar Auroras

Planetary auroral emissions are critical indicators of how the
magnetospheres of the planets work. Recently, a new component of
Saturn's auroral emissions, i.e. high latitude auroras inside the main
auroral oval, have been observed by the Cassini spacecraft during
otherwise quiet auroral conditions. Such high latitude auroras are of
immense interest since they occur on magnetic flux tubes connected to
a region that is key to the overall dynamics of the system, the
magnetotail, and where if conventional theories regarding Saturn's
magnetosphere are correct there should not be any auroras. These faint
auroral emissions have not been previously observed by the Hubble
Space Telescope (HST). However, the unique oblique viewing geometry
afforded during early 2009 due to Saturn's orbital longitude will
result in the apparent brightening of these polar emissions due to the
limb-brightening effect, with the result that they may be observable
by HST for the first ever time. In addition, at this time the Cassini
spacecraft will be in a high latitude orbit, with a trajectory that
will take it through these magnetic flux tubes, providing essential
simultaneous in situ data. This is the last time Cassini will be in
such an orbit during its mission as currently scheduled and HST is the
only instrument capable of obtaining sustained long-term observations
of Saturn's auroras. These observations will address the following:
Does Saturn exhibit high latitude UV auroras observable by HST? Where
do these auroras occur, and at what altitude? How do these auroras
behave over time? How variable are they? Are they periodic? How do
they behave with respect to other auroral components? What processes
drive these auroras?

Are these auroras generated by processes internal to the magnetosphere
or are they driven by the solar wind? How do the infrared (IR) auroras
relate to the ultraviolet (UV) auroras?

FGS 11706

The Parallax of the Planet Host Star XO-3

We will use HST+FGS to measure the parallax of the transiting planet
host star XO-3. The resulting accurate distance measurement will
provide the most accurate radius determination to date for this
massive extrasolar planet (XO-3b), allowing us to critically test
current giant extrasolar planet structure models. These observations
will also constrain the amount of heating that may be produced inside
XO-3b by tides raised on the planet as it moves through its 3.2 d
eccentric (e ~ 0.22) orbit.

WFPC2 11796

WFPC2 Cycle 16 Decontaminations and Associated Observations

This proposal is for the WFPC2 decons. Also included are instrument
monitors tied to decons: photometric stability check, focus monitor,
pre- and post-decon internals (bias, intflats, kspots, & darks), UV
throughput check, VISFLAT sweep, and internal UV flat check.

WFPC2 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 to observe using 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 11966

The Recent Star Formation History of SINGS Galaxies

The Spitzer Legacy project SINGS provided a unique view of the current
state of star formation and dust in a sample of galaxies of all Hubble
types. This multi-wavelength view allowed the team to create current
star formation diagnostics that are independent of the dust content
and increased our understanding of the dust in galaxies. Even so,
using the SINGS data alone we can only make rough estimates of the
recent star formation history of these galaxies. The lack of high
resolution observations (especially U-band and H-alpha) means that it
is impossible to estimate the ages of young clusters. In addition, the
low resolution of the Spitzer and ground-based observations means that
what appear to be individual Spitzer sources can actually be composed
of many individual clusters with varying ages. We need to know the
ages, star formation histories, and extinction of these individual
clusters to understand how these clusters form and age and thus
influence the evolution of the galaxy. In this proposal we address
this missing area of SINGS by obtaining high-resolution WFPC2 UBVI &
H-alpha observations to not only accurately locate and determine the
ages of the young stellar clusters in the actively star forming SINGS
galaxies but to also address a variety of other scientific issues.
Over 500 HST orbits and 500 hours of Spitzter observing time have been
dedicated to observations of the SINGS sample. But the HST
observations have not been systematic. By adding a relatively small
fraction of this time for these requested observations, we will
greatly enhance the legacy value of the SINGS observations by creating
a uniform high resolution multi-wavelength HST archive that matches
the quality of the lower resolution SINGS archive.

WFPC2 11989

The Integral Sign Galaxy

We will observe the unusual warped disk galaxy known as the Integral
Sign Galaxy, UGC 3697, with a small two-position WFPC2 mosaic.
Observations will be obtained in three broad band filters and the
resulting image will be released on the 19th anniversary of the launch
of the Hubble Space Telescope on ~April 24, 2009. Multidrizzled
mosaics will be made available through the archive.

FLIGHT OPERATIONS SUMMARY:

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

HSTARS:

11678 - GSAcq(1,3,3) Loss of Lock while HST guiding under two FGSs @
048/1100z

Observations possibly affected: WFPC 53 & 54, Proposal ID# 11989

11679 - REAcq(1,3,3) fails to Gyro Control, V1 error was too large to
correct @ 048/1404z

Observations affected: WFPC 57 & 58, Proposal ID# 11989.

11680 - REAcq(1,3,3) failed to RGA Hold due to Stop Flag on FGS-1 @
048/1534z

Observations affected: WFPC 59 and 60, Proposal ID# 11989

11681 - REAcq (1,3,3) failed to RGA Hold due to QF1STOPF flag on FGS-1 @
048/1848z

Observations affected: WFPC 63 & 64, Proposal ID# 11989.

11682 - REAcq(1,3,3) fails to Gyro Control, V1 error was too large to
correct @ 048/2047z

Observations affected: WFPC 65 & 66, Proposal ID# 11989

11683 - REAcq (1,3,3) failed to RGA Hold due to QF1STOPF flag on FGS-1
@ 048/2306z

Observations affected: WFPC 67 & 68, Proposal ID# 11989

COMPLETED OPS REQUEST: (None)

COMPLETED OPS NOTES: (None)

*********************** SCHEDULED***** SUCCESSFUL***** FAILURE TIMES

FGS GSacq************** 07**************** 07
FGS REacq************** 08**************** 03
OBAD with Maneuver **** 30**************** 30
LOSS of LOCK******************************************** 048/1100z

SIGNIFICANT EVENTS: (None)