HUBBLE
SPACE TELESCOPE - Continuing to collect World Class Science
DAILY
REPORT #4911
PERIOD
COVERED: 5am August 17 - 5am August 18, 2009 (DOY 229/09:00z-230/09:00z)
OBSERVATIONS
SCHEDULED
COS/FUV
11492
FUV
Sensitivity
This
activity confirms COS sensitivity versus wavelength over the entire
observable
spectrum for all FUV gratings and central wavelength
settings.
Obtain quick look sensitivity visit early in SMOV. Later,
after
wavelength calibration is verified, perform a precise-centering
acquisition
and observe an appropriate HST flux standard star (chosen
from
the HST prime standard and FASTEX lists) with the PSA. (A limited
BOA
characterization is obtained in Visit 13 using primary standard
GD153.)
No off aperture- center observations are performed in this
activity
(see COS32, program 11490, for off- center characterizations).
Spectra
will be obtained to meet a Poisson S/N criterion of ~30 per
sensitivity
extraction bin or higher; substantially higher S/N
characterization
will be utilized in routine Cycle 17 calibration.
COS/NUV/FUV
11486
COS
FUV Target 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, using dispersed
light
from the object using the FUV gratings. The various options for
target
centering should be exercised and shown to work properly. This
test
is for acquisitions in dispersed-light mode only. This program is
modeled
from SMOV activity summary COS28.
This
program should be executed two or more weeks after visit 12 of
11469,
and after the SIAF update, so that we have confirmed that NUV
imaging
acquisitions work properly with the BOA.
STIS/CCD
11567
Boron
Abundances in Rapidly Rotating Early-B Stars
Models
of rotation in early-B stars predict that rotationally driven
mixing
should deplete surface boron abundances during the main-sequence
lifetime
of many stars. However, recent work has shown that many boron
depleted
stars are intrinsically slow rotators for which models predict
no
depletion should have occurred, while observations of nitrogen in
some
more rapidly rotating stars show less mixing than the models
predict.
Boron can provide unique information on the earliest stages of
mixing
in B stars, but previous surveys have been biased towards
narrow-lined
stars because of the difficulty in measuring boron
abundances
in rapidly rotating stars.The two targets observed as part of
our
Cycle 13 SNAP program 10175, just before STIS failed, demonstrate
that
it is possible to make useful boron abundance measurements for
early-B
stars with Vsin(i) above 100 km/s. We propose to extend that
survey
to a large enough sample of stars to allow statistically
significant
tests of models of rotational mixing in early-B stars.
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.
STIS/CCD
11851
Slit
Wheel Repeatability
Test
the repeatibility of the slit wheel by taking a sequence of
comparison
lamp spectra with grating G230MB (2697) and the three
smallest
long slits (52X0.2, 52X0.1, and 52X0.05). This is a clone of
Cycle
12 Program 10029.
STIS/MA1
11861
MAMA
FUV Flats
This
program will obtain FUV-MAMA observations of the STIS internal
Krypton
lamp to construct an FUV flat applicable to all FUV modes.
STIS/MA2
11862
MAMA
NUV Flats
This
program will obtain NUV-MAMA observations of the STIS internal
Deuterium
lamp to construct an NUV flat applicable to all NUV modes.
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
11428
D2
Calibration Lamp Test
This
proposal verifies the health and performance of the calsystem
deuterium
lamp and assesses the status of the major UV filters by taking
a
full set of internal flatfields. A total of three nominal and one
short
exposure are obtained for each filter in order to establish an
initial
baseline of flatfield data as well as to confirm lamp
repeatability
and provide a contamination check. Additional iterations
of
D2 internal flatfields will be taken as part of WFC-19, UVIS Internal
Flats
(proposal 11432).
This
proposal corresponds to SMOV ID WFC3-15. It should not be run until
after
the successful completion of WFC-06, the UVIS detector functional
test
(proposal 11419) and WFC-11, the initial UVIS alignment (proposal
11424).
WFC3
11447
WFC3
IR Dark Current, Readnoise, and Background
This
proposal obtains full-frame, four-amp readout images.
Un-illuminated
internals are taken at regularly spaced intervals
throughout
SMOV in order to assess and monitor readnoise and dark
current
(of both light-sensitive pixels and reference pixels), and bad
(warm,
hot, dead, variable) pixels. In addition, externals aimed at
fields
with sparse stellar density are taken to measure diffuse
background
light.
This
program corresponds to WFC3-34.
WFC3/IR
11915
IR
Internal Flat Fields
This
program is the same as 11433 (SMOV) and depends on the completion
of
the IR initial alignment (program 11425). This version contains three
instances
of 37 internal orbits; to be scheduled early, middle, and near
the
end of Cycle 17, in order to use the entire 110-orbit allocation.
In
this test, we will study the stability and structure of the IR
channel
flat field images through all filter elements in the WFC3-IR
channel.
Flats will be monitored, i.e. to capture any temporal trends in
the
flat fields, and delta flats produced. High signal observations will
provide
a map of the pixel-to-pixel flat field structure, as well as
identify
the positions of any dust particles.
WFC3/IR
11937
IR
Grism Wavelength Calibration
This
program will determine the wavelength calibration for the IR G102
and
G141 grisms as a function of spatial position within the field of
view.
The planetary nebula Vy2-2 will be observed in a 9-point pattern
in
the IR field of view, which will provide FoV-dependent dispersion
maps
for the G102 and G141 grisms.
WFC3/UVI
11657
The
Population of Compact Planetary Nebulae in the Galactic Disk
We
propose to secure narrow- and broad-band images of compact planetary
nebulae
(PNe) in the Galactic Disk to study the missing link of the
early
phases of post-AGB evolution. Ejected AGB envelopes become PNe
when
the gas is ionized. PNe expand, and, when large enough, can be
studied
in detail from the ground. In the interim, only the HST
capabilities
can resolve their size, morphology, and central stars. Our
proposed
observations will be the basis for a systematic study of the
onset
of morphology. Dust properties of the proposed targets will be
available
through approved Spitzer/IRS spectra, and so will the
abundances
of the alpha-elements. We will be able thus to explore the
interconnection
of morphology, dust grains, stellar evolution, and
populations.
The target selection is suitable to explore the nebular and
stellar
properties across the Galactic Disk, and to set constraints on
the
galactic evolutionary models through the analysis of metallicity and
population
gradients.
WFC3/UVI
11905
WFC3
UVIS CCD Daily Monitor
The
behavior of the WFC3 UVIS CCD will be monitored daily with a set of
full-frame,
four-amp bias and dark frames. A smaller set of 2Kx4K
subarray
biases are acquired at less frequent intervals throughout the
cycle
to support subarray science observations. The internals from this
proposal,
along with those from the anneal procedure (11909), will be
used
to generate the necessary superbias and superdark reference files
for
the calibration pipeline (CDBS).
WFC3/UVI
11907
UVIS
Cycle 17 Contamination Monitor
The
UV throughput of WFC3 during Cycle 17 is monitored via weekly
standard
star observations in a subset of key filters covering 200-600nm
and
F606W, F814W as controls on the red end. The data will provide a
measure
of throughput levels as a function of time and wavelength,
allowing
for detection of the presence of possible contaminants.
WFC3/UVI
11908
Cycle
17: UVIS Bowtie Monitor
Ground
testing revealed an intermittent hysteresis type effect in the
UVIS
detector (both CCDs) at the level of ~1%, lasting hours to days.
Initially
found via an unexpected bowtie-shaped feature in flatfield
ratios,
subsequent lab tests on similar e2v devices have since shown
that
it is also present as simply an overall offset across the entire
CCD,
i.e., a QE offset without any discernable pattern. These lab tests
have
further revealed that overexposing the detector to count levels
several
times full well fills the traps and effectively neutralizes the
bowtie.
Each visit in this proposal acquires a set of three 3x3 binned
internal
flatfields: the first unsaturated image will be used to detect
any
bowtie, the second, highly-exposed image will neutralize the bowtie
if
it is present, and the final image will allow for verification that
the
bowtie is gone.
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: (None)
COMPLETED
OPS NOTES: (None)
SCHEDULED
SUCCESSFUL
FGS
GSAcq
06
06
FGS
REAcq
10
10
OBAD
with Maneuver
05
05
SIGNIFICANT
EVENTS: (None)