HUBBLE
SPACE TELESCOPE - Continuing to collect World Class Science
DAILY
REPORT #4901
PERIOD
COVERED: 5am August 3 - 5am August 4, 2009 (DOY 215/09:00z-216/09:00z)
OBSERVATIONS
SCHEDULED
ACS
11465
ACS
CCD Monitoring and Calibration for WFC3
This
program is a smaller version of our routine CCD monitoring program,
designed
to run throughout SMOV, after which our regular Cycle 17 CAL
proposal
will begin. This program obtains the bias and dark frames
needed
to generate reference files for calibrating science data, and
allows
us to monitor detector noise and the growth of hot pixels.
COS
11471
COS
NUV Imaging Acquisition Algorithm Verification
Verify
the ability of the COS FSW to place an isolated point source at
the
center of the aperture, both for the BOA and PSA, and for MIRRORA
and
MIRRORB. The various
options
for target centering should be exercised and shown to work
properly.
This test is for acquisitions in imaging mode only.
Acquisitions
using dispersed light are tested in separate SMOV
activities.
FGS
11788
The
Architecture of Exoplanetary Systems
Are
all planetary systems coplanar? Concordance cosmogony makes that
prediction.
It is, however, a prediction of extrasolar planetary system
architecture
as yet untested by direct observation for main sequence
stars
other than the Sun. To provide such a test, we propose to carry
out
FGS astrometric studies on four stars hosting seven companions. Our
understanding
of the planet formation process will grow as we match not
only
system architecture, but formed planet mass and true distance from
the
primary with host star characteristics for a wide variety of host
stars
and exoplanet masses.
We
propose that a series of FGS astrometric observations with
demonstrated
1 millisecond of arc per-observation precision can
establish
the degree of coplanarity and component true masses for four
extrasolar
systems: HD 202206 (brown dwarf+planet); HD 128311
(planet+planet),
HD 160691 = mu Arae (planet+planet), and HD 222404AB =
gamma
Cephei (planet+star). In each case the companion is identified as
such
by assuming that the minimum mass is the actual mass. For the last
target,
a known stellar binary system, the companion orbit is stable
only
if coplanar with the AB binary orbit.
STIS/CCD
11844
CCD
Dark Monitor Part 1
Monitor
the darks for the STIS CCD.
STIS/CCD
11846
CCD
Bias Monitor-Part 1
Monitor
the bias in the 1x1, 1x2, 2x1, and 2x2 bin settings at gain=1,
and
1x1 at gain = 4, to build up high-S/N superbiases and track the
evolution
of hot columns.
STIS11
11386
STIS-11
External Focus Check
This
proposal will check the STIS focus and alignment using two tests.
In
the first test, ACQ/PEAK exposures with the G230LB are used to dither
the
0.1x0.09 aperture across a point source to sample the PSF. Relative
counts
at different wavelengths give a measure of PSF shape at different
wavelengths.
Full frame comparison exposures will also taken using the
0.1X0.09
and 52X2 apertures, and the relative aperture throughputs will
give
an estimate of the image quality at the STIS aperture plane. In the
second
test, the target is imaged onto the STIS CCD using the
narrow-band
F28x50OII filter. Comparison with previous OII images will
be
done to estimate the state of the focus.
STIS20
11402
STIS-20
NUV MAMA Dark Monitor
The
STIS NUV-MAMA dark current is dominated by a phosphorescent glow
from
the detector window. Meta-stable states in this window are
populated
by cosmic ray impacts, which, days later, can be thermally
excited
to an unstable state from which they decay, emitting a UV
photon.
The equilibrium population of these meta-stable states is larger
at
lower temperatures; so warming up the detector from its cold safing
will
lead to a large, but temporary, increase in the dark current.
To
monitor the decay of this glow, and to determine the equilibrium dark
current
for Cycle 17, four 1380s NUV-MAMA ACCUM mode darks should be
taken
each week during the SMOV period. Once the observed dark current
has
reached an approximate equilibrium with the mean detector
temperature,
the frequency of this monitor can be reduced to one pair of
darks
per week.
WFC3
11552
Characterization
of the WFC3 IR Grisms
Image
displacement, spectral trace and dispersion, and throughput of the
IR
G102 and G141 grisms will be verified. The HST flux standard GD 153
will
be observed in a 5-point pattern in the IR field of view, which
will
provide image displacement, spectral trace, and throughput
measurements
as a function of location within the FOV. Similarly, the
planetary
nebula PN HB12 will be observed in a 9-point pattern in the IR
field
of view, which will provide dispersion measurements as a function
of
FOV position.
WFC3
11808
WFC3
UVIS Bowtie Monitor
The
UVIS detector was observed during ground testing to occasionally
exhibit
flat field and dark variations with a bowtie pattern. These
variations
are most significant as ~1% flat field (gain) variations
across
the field of view. It is believed that this represents a state or
condition
into which the detector can transition for reasons and under
circumstances
which are not currently understood. It is also very
unlikely
that most science observations will determine the state (bowtie
or
no-bowtie) of the detector. Ground test data indicates that this
state
is long lived (many hours to ~one day). Hysteresis or memory of
past
light exposure is also associated with this state.
Recent
evidence suggests that exposing the detector to ~200k to 500k
electrons
may quench this state. This proposal obtains an internal flat
field
sequence of three exposures: one at 10x full well with two at 0.5x
full
well immediately before and after. Each exposure is 3x3 binned to
reduce
the data volume required.
These
visits should be scheduled 2x per day until further direction is
provided.
WFC3/ACS/UVI
11877
HST
Cycle 17 and Post-SM4 Optical Monitor
This
program is the cycle 17 implementation of the HST Optical
Monitoring
Program.
The
36 orbits comprising this proposal will utilize ACS (Wide Field
channel)
and WFC3 (UVIS channel) to observe stellar cluster members in
parallel
with multiple exposures over an orbit. Phase retrieval
performed
on the PSF in each image will be used to measure primarily
focus,
with the ability to explore apparent coma, and astigmatism
changes
in WFC3. The goals of this program are to: 1) monitor the
overall
OTA focal length for the purposes of maintaining focus within
science
tolerances 2) gain experience with the relative effectiveness of
phase
retrieval on WFC3/UVIS PSFs 3) determine focus offset between the
imagers
and identify any SI-specific focus behavior and dependencies
If
need is determined, future visits will be modified to interleave
WFC3/IR
channel and STIS/CCD focii measurements.
WFC3/UVI
11565
A
Search for Astrometric Companions to Very Low-Mass, Population II
Stars
We
propose to carry out a SNAPshot search for astrometric companions in
a
subsample of very low-mass, halo subdwarfs identified within 120
parsecs
of the Sun. These ultra- cool M subdwarfs are local
representatives
of the lowest-mass H-burning objects from the Galactic
Population
II. The expected 3-4 astrometric doubles that will be
discovered
will be invaluable in that they will be the first systems
from
which gravitational masses of metal-poor stars at the bottom of the
main
sequence can be directly measured.
WFC3/UVI
12003
The
Impact Event on Jupiter in 2009
An
image of Jupiter taken on 19 July 2009 at 15 UT showed an anomalous
feature
in the southern hemisphere. The world-wide community responded
with
observations, and the subsequent data strongly suggest that an
impact
occurred during the 8 hours preceding that discovery image. The
Hubble
Space Telescope is the only facility that can provide
high-spatial-resolution
visible images of the impact site, and the only
facility
that can provide UV images that show the impactor's effect on
the
Jovian stratosphere. We request 7 orbits of HST time to characterize
this
rare event. We hope that two orbits can be as soon as is feasible
(Wednesday
or Thursday, 22 or 23 July). We would like a second pair
several
days later, perhaps Saturday. We request another 2 orbits the
following
week. The last, seventh, orbit can be several weeks or a month
later.
FLIGHT
OPERATIONS SUMMARY:
Significant
Spacecraft Anomalies: (The following are preliminary reports
of
potential non-nominal performance that will be investigated.)
HSTARS:
None
COMPLETED
OPS REQUEST:
18667-0
- Null genslews for proposals 11474, 11492, and 11505 - slots 1-3 @ 215/1516z
18669-0
- Clear STIS MAMA 2 Event Flag 3 @ 215/1533z
18670-0
- Recover MAMA2 MCE @ 215/2006z
COMPLETED
OPS NOTES: (None)
SCHEDULED
SUCCESSFUL
FGS
GSAcq
8
8
FGS
REAcq
7
7
OBAD
with Maneuver
6
6
SIGNIFICANT
EVENTS: (None)