HUBBLE SPACE TELESCOPE - Continuing to Collect World Class Science

DAILY REPORT       #4930

PERIOD COVERED: 5am September 14 - 5am September 15, 2009 (DOY 257/09:00z-258/09:00z)

OBSERVATIONS SCHEDULED

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.

COS/FUV 11482

FUV Detector Dark

The purpose of this proposal is to measure the FUV detector dark rate by
taking long science exposures with no light on the detector. The
detector dark rate and spatial distribution of counts will be compared
to pre-launch data in order to verify the nominal operation of the
detector, and for use in the CalCOS calibration pipeline. Variations of
count rate as a function of orbital position will be analyzed to find
dependence of dark rate on proximity to the SAA.

This is SMOV Activity COS-24.

COS/FUV 11490

COS FUV External Spectroscopic Performance - Part 2

The goal of this activity is to verify the spatial resolution of COS in
the FUV and to characterize the interdependence of the spatial and
spectral resolution of the instrument in that wavelength band. By
stepping the source along the cross-dispersion direction out to the edge
of the PSA, we will be able to quantify the variation of the spatial
profile of the source with off-axis position, both by measuring the
shape and width of the profile and by measuring the amount of flux
transmitted through the aperture as the source is stepped past the edge
of the aperture. Aside from measuring the spatial resolution of COS
spectra, this study will be particularly useful for understanding the
contamination of sources near the targeted object in crowded stellar
fields.

This test is ideally performed with a spatially unresolved point source
with an emission line spectrum. Our observations with the PSA will
target the symbiotic star LIN 358 in the Large Magellanic Cloud. This
star produces little or no continuum in the FUV, but exhibits line
emission from He II (particularly strong), C IV, N IV and N V. The
individual lines are unresolved in FOS spectra of this object, but the
lines within the C IV and N V doublets are well resolved from one
another. This indicates that the emission lines in the COS observations
are likely to be narrow (<~ 60 km/s).

These observations will implement the following procedure: 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 (~ 30 per
resel counting statistics) observations at one central wavelength
setting with the PSA. Next we repeat the sequence of observations at
each of five additional positions, with offsets of 0.25, 0.5, 1.0, 1.5,
and 1.75 arcseconds in the cross-dispersion (Y) direction from the
center of the aperture. The procedure is then repeated for five more
POSTARGs offset in the negative cross-dispersion direction (-Y). This
results in a total of 11 exposures with the G130M and G140L gratings.
For observations with the G160M grating we include an additional set of
5 POSTARGs each along the positive (+X) and negative (-X) dispersion
directions. The goal of these observations is to test variations in the
shape and width of the profile along the dispersion direction, and to
compare the results with those from the cross-dispersion direction.

All of these observations will be performed in Time-Tag mode with
Flash=Yes for all three FUV gratings, but with FP-POS set to the default
value of 3.

The observations with the BOA will be performed on the Galactic
symbiotic star AG Draconis (M_V = 9.8). This object is a bright
recurrent nova (period ~ 15 yrs) and a source of strong ultraviolet line
emission. Here we obtain a single Time-Tag exposure for each of the four
FUV gratings with the object centered in the BOA to evaluate the spatial
resolution in this mode. We aim for S/N = 20 for the brightest emission
line in each observation.

The number of exposures in this program is somewhat larger than the
number described in the Activity Summary, but is necessary to perform
the intended tests of the COS spectral resolution.

This activity is SMOV program COS 32.

Implementation Method: Stored Commanding

Data Requirements: Approximately 420 MB

Dependencies: Execute after verification based upon results of Activity
COS 30 (Internal FUV Wavelength Calibration) (SMOV Proposal 11488)

Applicable SMOV Requirements: L.10.4.2.3.12.2; L.10.4.2.3.12.3;
L.10.4.2.3.13

COS/FUV 11494

COS FUV High S/N Verification

Collect data for a single central wavelength for each FUV grating in
Time-Tag mode, using multiple FP-POS positions, in order to verify that
high signal-to-noise spectra can be obtained. All spectra will have
enough counts to permit standard reduction techniques to be used to
obtain spectra with a signal-to-noise ratio of more than 30.

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

The purpose of this proposal is to monitor the darks for the STIS CCD.

STIS/CCD 11846

CCD Bias Monitor-Part 1

The purpose of this proposal is to 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/MA1/MA2 11857

STIS Cycle 17 MAMA Dark Monitor

This proposal monitors the behavior of the dark current in each of the
MAMA detectors.

The basic monitor takes two 1380s ACCUM darks each week with each
detector. However, starting Oct 5, pairs are only included for weeks
that the LRP has external MAMA observations planned. The weekly pairs of
exposures for each detector are linked so that they are taken at
opposite ends of the same SAA free interval. This pairing of exposures
will make it easier to separate long and short term temporal variability
from temperature dependent changes.

For both detectors, additional blocks of exposures are taken once every
six months. These are groups of five 1314s FUV-MAMA Time-Tag darks or
five 3x315s NUV ACCUM darks distributed over a single SAA-free interval.
This will give more information on the brightness of the FUV MAMA dark
current as a function of the amount of time that the HV has been on, and
for the NUV MAMA will give a better measure of the short term
temperature dependence.

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 (Proposal 11909),
will be used to generate the necessary superbias and superdark reference
files for the calibration pipeline (CDBS).

WFC3/UVIS 11998

Determining the Rotational Phase of Comet 9P/Tempel 1 in Support of the
StardustNExT Mission

A primary objective of the StardustNExT mission is to image the crater
created by NASA's Deep Impact (DI) mission. The 12-year ground- and
space-based DI observing campaign provided an exceptional data set for
investigating the rotation of comet 9P/Tempel 1. The just-completed
analysis shows that the spin period increased in a stepwise manner
through the perihelia in 2000 and 2005, due to an outgassing of water
from a southern jet. Our water-sublimation jet torque model has been
moderately successful in predicting the integrated change in the nucleus
longitude at the 2005 perihelion and beyond, and has been used to
predict the rotation state at the planned Stardust-NExT encounter just
after perihelion on 02/14/2011. We propose a 19-orbit Hubble program to
perform light curve observations of 9P/Tempel 1 that will allow us to
determine the time-of-arrival adjustment of the Stardust-NExT spacecraft
trajectory that is needed to ensure that the spacecraft arrives at
encounter with the (as yet unseen) artificial DI crater at the
sub-spacecraft point and fully illuminated by the sun. The trajectory
correction maneuver is in Feb 2010, and we need to know the nucleus
rotation phase to a precision of 1% and the period to 10 sec by Jan
2010. HST is the only facility capable of obtaining the high-quality
data necessary to determine the shape and phase of the rotational light
curve. When combined with ground-based data 2-3 months later, we will
achieve the required precision.

WFC3/UVIS/IR 11909

UVIS Hot Pixel Anneal

The on-orbit radiation environment of WFC3 will continually generate new
hot pixels. This proposal performs the procedure required for repairing
those hot pixels in the UVIS CCDs. During an anneal, the two-stage
thermo-electric cooler (TEC) is turned off and the four-stage TEC is
used as a heater to bring the UVIS CCDs up to ~20 deg. C. As a result of
the CCD warmup, a majority of the hot pixels will be fixed; previous
instruments such as WFPC2 and ACS have seen repair rates of about 80%.
Internal UVIS exposures are taken before and after each anneal, to allow
an assessment of the procedure's effectiveness in WFC3, provide a check
of bias, global dark current, and hot pixel levels, as well as support
hysteresis (bowtie) monitoring and CDBS reference file generation. One
IR dark is taken after each anneal, to provide a check of the IR
detector.

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:
18701-0 - Null genslew for proposal 11487 - slot 2 @ 257/16:58z

COMPLETED OPS NOTES: (None)

                        SCHEDULED     SUCCESSFUL
FGS GSAcq                04                 04             
FGS REAcq                12                 12                
OBAD with Maneuver 04                 04                       

SIGNIFICANT EVENTS: (None)