Daily Report #4930

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 procedu 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)