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
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)