Daily # 4208

HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

DAILY REPORT # 4208

PERIOD COVERED: UT September 27, 2006 (DOY 270)

OBSERVATIONS SCHEDULED

NIC1/NIC2/NIC3 8794

NICMOS Post-SAA calibration - CR Persistence Part 5

A new procedure proposed to alleviate the CR-persistence problem of
NICMOS. Dark frames will be obtained immediately upon exiting the SAA
contour 23, and every time a NICMOS exposure is scheduled within 50
minutes of coming out of the SAA. The darks will be obtained in
parallel in all three NICMOS Cameras. The POST-SAA darks will be
non-standard reference files available to users with a USEAFTER
date/time mark. The keyword 'USEAFTER=date/time' will also be added to
the header of each POST-SAA DARK frame. The keyword must be populated
with the time, in addition to the date, because HST crosses the SAA ~8
times per day so each POST-SAA DARK will need to have the appropriate
time specified, for users to identify the ones they need. Both the raw
and processed images will be archived as POST-SAA DARKSs. Generally we
expect that all NICMOS science/calibration observations started within
50 minutes of leaving an SAA will need such maps to remove the CR
persistence from the science images. Each observation will need its
own CRMAP, as different SAA passages leave different imprints on the
NICMOS detectors.

NIC2 10527

Imaging Scattered Light from Debris Disks Discovered by the Spitzer
Space Telescope Around 20 Sun-like Stars

We propose to use the high contrast capability of the NICMOS
coronagraph to image a sample of newly discovered circumstellar disks
associated with sun-like stars. These systems were identified by their
strong thermal infrared emission with the Spitzer Space Telescope as
part of the Spitzer Legacy Science program titled, "The Formation and
Evolution of Planetary Systems {FEPS}." Modelling of the thermal
excess emission in the form of spectral energy distributions alone
cannot distinguish between narrowly confined high opacity disks and
broadly distributed, low opacity disks. However, our proposed NICMOS
observations can, by imaging the light scattered from this material.
Even non- detections will place severe constraints on the disk
geometry, ruling out models with high optical depth. Unlike previous
disk imaging programs, our program contains a well defined sample of
solar mass stars covering a range of ages from ~10Myrs to a few Gyrs,
allowing us to study the evolution of disks from primordial to debris
for the first time. These results will greatly improve our
understanding of debris disks around Sun- like stars at stellar ages
nearly 10x older than any previous investigation. Thus we will have
fit a crucial piece into the puzzle concerning the formation and
evolution of our own solar system.

NIC3 10780

The Unusual Afterglow and Host Galaxy of the Short GRB 060121

We request Director's Discretionary Time to observe the afterglow and
host galaxy of the short- hard gamma-ray bursts GRB 060121. This is
only the fourth time an optical afterglow of a short- hard burst has
been found at its properties are significantly different to other
cases. Both the afterglow and host galaxy are much fainter than
previous short bursts {for which optical afterglows have been located}
and the afterglow may also show the signature of dust extinction. Such
extinction is completely unexpected for short bursts, given the
currently popular model of their origin in NS-NS mergers. We propose
ACS and NICMOS observations which will locate the afterglow and host
galaxy of GRB 060121, provide constraints on its beaming angle, search
for the signature of dust, and measure the offset from its host. These
observations offer a strong test of NS-NS merger models.

NIC3 10899

Identifying z7 galaxies from J-dropouts

NICMOS Parallel Imaging campaigns covered enough sky {250 pointings}
with enough sensitivity in the 110W and 160W filters to identify 6
extremely red resolved sources which are prime candidates for J-band
dropouts. Their complete absence of detectable J band flux can be
caused by an opaque Lyman cut-off at z=8-10. We propose to followup
these candidates with NICMOS imaging and jointly propose Spitzer IRAC
photometry. Deep F110W and Spitzer/IRAC 3.5/4.8 micron imaging will
confirm if any of these candidates are indeed Lyman Break galaxies
observed less than 500 Myrs after the Big Bang. Genuine LBGs will
remain undetected in F110W, while being detected with flat spectra in
the IRAC bands. The combined SED will provide information about the
stellar mass of these galaxies, and the possible presence of evolved
stars or dust reddening. The proposed observations will be sensitive
enough to detect the F110W flux from galaxies as red as {J-H}=2.8 {AB
mags, 5 sigma}. If any of the candidates are detected with bluer
colors, they will most likely be exceptional "Distant Red Galaxies" at
z of 4 to 6. The proposed data will constrain the stellar populations
of these extraordinarily red galaxies, which would be candidates for
the earliest, most massive galaxies which formed.

FLIGHT OPERATIONS SUMMARY:

Significant Spacecraft Anomalies: (The following are preliminary
reports of potential non-nominal performance that will be
investigated.)

HSTARS:

10450 - GSacq(2,1,2) failed

GSacq(2,1,2) scheduled at 270/17:09:05 failed to RGA control with
QF2STOPF and QSTOP flags set at 17:14:24. No other flag were seen.
OBAD1 showed errors of V1= -1081.30, V2= 905.51, V3= -2395.45, RSS=
2779.48. OBAD2 showed errors of V1= 9.75, V2= -1.79, V3= 9.77, RSS=
13.92.

COMPLETED OPS REQUEST:


COMPLETED OPS NOTES: (None)

SCHEDULED SUCCESSFUL
FGS GSacq 04 03
FGS REacq 06 06
OBAD with Maneuver 20 20

SIGNIFICANT EVENTS:

SA Section Anomaly Investigation Flash Report #1

On DOY 2006/270, the commanding for the SA Sections 1 and 5 Current
Anomaly Investigation commenced at 13:16 GMT with the opening of the
+E SPA trim relay on SA section 5. A distinct fault current behavior
was observed - SA section 1 current experienced a step decrease of
~1.4A concurrent with opening the +E SPA trim relay.

In two subsequent test orbits, the step decrease in SA section 1
current did not occur simultaneously with off-lining the -A (SA
section 5) and +DD (SA section 1) SPAs. Instead there was a ~1A step
decrease in SA section 1 current when battery 5 reached charge cut-off
later in the orbit (similar to fault behavior in most orbits since the
initial event on DOY 2006/222).

In all orbits, SA section 5 current has continued to read ~1.8A higher
than nominal when battery 5 reached charge cut-off.

The investigation will continue with the commanding of the last two
remaining SPA trim relays, -CC and +D, on DOY 2006/271 at 13:15 GMT
(Thursday, September 28th at 9:15 am local). An additional flash
report will be provided at the completion of the test.