HUBBLE
SPACE TELESCOPE - Continuing to Collect World Class Science
DAILY
REPORT #4921
PERIOD
COVERED: 5am August 31 - 5am September 1, 2009 (DOY 243/09:00z-244/09:00z)
OBSERVATIONS
SCHEDULED
ACS/WFC3
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.
ACS/WFC3
11879
CCD
Daily Monitor (Part 1)
This
program comprises basic tests for measuring the read noise and dark
current
of the ACS WFC and for tracking the growth of hot pixels. The
recorded
frames are used to create bias and dark reference images for
science
data reduction and calibration. This program will be executed
four
days per week (Mon, Wed, Fri, Sun) for the duration of Cycle 17. To
facilitate
scheduling, this program is split into three proposals. This
proposal
covers 352 orbits (22 weeks) from 31 August 2009 to 31 January
2010.
ACS/WFC3
11882
CCD
Hot Pixel Annealing
All
the data for this program is acquired using internal targets (lamps)
only,
so all of the exposures should be taken during Earth occultation
time
(but not during SAA passages). This program emulates the ACS
pre-flight
ground calibration and post-launch SMOV testing (program
8948),
so that results from each epoch can be directly compared.
Extended
Pixel Edge Response (EPER) and First Pixel Response (FPR) data
will
be obtained over a range of signal levels for the Wide Field
Channel
(WFC). The High Resolution Channel (HRC) visits have been
removed
since it could not be repaired during SM4.
COS/FUV
11488
Internal
FUV Wavelength Verification
This
program will be executed after the uplink of the OSM1 position
updates
derived from the determination of the wavelength-scale zero
points
and desired spectral ranges for each grating in Activity COS29
(Program
11487 - COS FUV Internal/External Wavelength Scales). This
program
will verify that the operational spectral ranges for each
grating,
central wavelength, and FP-POS are those desired. Subsequent to
a
successful verification, COS FUV ERO observations that require
accurate
wavelength scales (if any) and FUV science can be enabled. An
internal
wavelength calibration spectrum using the default PtNe lamp
(lamp
1) with each FUV grating at each central wavelength setting and
each
FP-POS position will be obtained for the verification. Additional
exposures
and waits between certain exposures will be required to avoid
-
and to evaluate - mechanism drifts.
COS/FUV
11489
COS
FUV External Spectroscopic Performance - Part 1
The
goal of this project is to measure the spectral resolution of
absorption
lines for each COS FUV grating. We will acquire science data
at
one central wavelength for each grating through both PSA and BOA
apertures.
We will evaluate the spectral resolution at offset pointings
characteristic
of routine COS observations. The targets chosen for these
observations
have sharp absorption lines. First, a target acquisition is
performed
to place the target at the center of the aperture. For each
FUV
grating we obtain moderately high S/N (~50 per resel counting
statistics)
observations at one central wavelength setting with the PSA.
We
repeat the sequence of observations at each of four additional
POS-TARG
pointings to form a diamond pattern whose vertices are
displaced
0.25 arcsec in either X or Y from the initial pointing. The
purpose
of these observations is to characterize the degradation in
spectral
resolution due to small positioning errors in the peakup
process.
These observations will be obtained in Time-Tag mode and will
utilize
Flash=Yes. The total exposure time in all 4 offset positions is
equal
to the exposure time at the central position. At each offset
position,
there are two exposures, one each at FP positions 3 and 1. For
one
grating (G130M) and central wavelength (1291) only we obtain a
Time-Tag
exposure with Flash=No to verify auto-wavecal capability. In
addition,
on a brighter target, we obtain a single TTag exposure for
each
grating with the object centered in the BOA aperture, in order to
measure
the spectral resolution in this mode. These spectra will have
S/N=20.
Finally, for each grating we obtain one Time-Tag exposure and
one
ACCUM exposure with the object centered in the aperture to verify
that
the Doppler correction is being properly exectuted on board in
ACCUM
mode.
The
number of exposures in this program is somewhat greater than is
described
in the Activity Summary, but reflects what was intended to be
measured.
This
is SMOV Program COS 31.
Implementation
Method: Stored commanding
Dependencies:
Execute after verification based upon analysis of COS 30
(Internal
FUV Wavelength Verification)
Applicable
SMOV Requirements: L.10.4.2.3.12.2; L.10.4.2.3.13;
L.10.4.2.1.8.
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
11853
Cycle
17 STIS CCD Imaging Flats
This
program periodically monitors the STIS CCD imaging mode flat fields
by
using the tungsten lamps.
STIS/CCD/FGS
11848
CCD
Read Noise Monitor
This
proposal measures the read noise of all the amplifiers (A, B, C, D)
on
the STIS CCD using pairs of bias frames. Full-frame and binned
observations
are made in both Gain 1 and Gain 4, with binning factors of
1x1,
1x2, 2x1, and 2x2. All exposures are internals. Pairs of visits are
scheduled
monthly for the first four months and then bi-monthly after
that.
STIS/MA1
11649
Elucidating
the Mystery of the Io Footprint Time Variations
The
Io UV footprint (IFP) is an auroral emission on Jupiter consisting
of
one or more spots resulting from the electromagnetic interaction
between
Io and the Jovian magnetosphere. Recent UV HST observations of
the
Jovian aurora raised new issues and put previous interpretations
under
question. Dedicated STIS Time-tag observations based on only 3 HST
orbits
will help us to directly answer the following questions and test
new
hypothesis on the physics driving their associated phenomenon.
The
proposed observations will determine whether the previously observed
short
timescale (~2 min) variations of the IFP are periodic or burst
events.
If the (quasi-) periodicity is established, these constraints
will
help us to understand the origin of these variations. These
observations
will also clarify the conditions of occurrence of the
unexpected
quasi-simultaneous variations of the southern multiple spots
of
the IFP. Moreover, we propose to observe the emergence of the
southern
leading (or precursor) spot and the possible evolution of its
brightness.
These two elements might validate or exclude the recently
proposed
idea that cross-hemisphere electron beams or strong non-
linearities
of the electromagnetic interaction explain the presence of
the
leading and secondary spots.
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/UVIS
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/UVIS
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.
WFC3/UVIS
11924
WFC3/UVIS
External and Internal CTE Monitor
CCD
detector Charge Transfer Inefficiency (CTI)-induced losses in
photometry
and astrometry will be measured using observations of the
rich
open cluster NGC6791 and with the EPER (Extended Pixel Edge
Response)
method using tungsten lamp flat field exposures. Although we
do
not expect to see CTE effects at the outset of Cycle 17, this CTE
monitoring
program is the first of a multi-cycle program to monitor and
establish
CTE-induced losses with time. We expect to measure CTE effects
with
a precision comparable to the ACS measurements.
FLIGHT
OPERATIONS SUMMARY:
Significant
Spacecraft Anomalies: (The following are preliminary reports
of
potential non-nominal performance that will be investigated.)
HSTARS:
11996
- GSAcq(1,2,1) scheduled at 243/13:53:25z - 14:00:56 failed to fine
lock backup (1,0,1) using FGS-1.
Observations possibly affected: COS 62 thru 68, Proposal ID# 11489
Subsequent REAcq(1,2,1) scheduled at 243/15:27:26z resulted in fine
lock backup (1,0,1) using FGS-1.
Observations possibly affected: COS 71 thru 76 Proposal ID# 11489,
ACS 26 Proposal ID# 11879.
HSTARS
FOR DAY 226:
11997
- GSAcq(2,1,1) at 226/03:52:43z required two attempts to achieve
FL-DV on FGS2. FGS2 initially failed a walkdown with scan step limit
exceeded, but was able to achieve FL-DV on the second try. The
acquisition was successful.
COMPLETED
OPS REQUEST: (None)
COMPLETED
OPS NOTES: (None)
SCHEDULED SUCCESSFUL
FGS
GSAcq 08 08
FGS
REAcq 10 10
OBAD
with Maneuver 07 07
SIGNIFICANT
EVENTS: (None)