HUBBLE SPACE TELESCOPE - Continuing to collect World Class
Science
DAILY REPORT #4696
PERIOD COVERED: 5am September 15 - 5am September 16, 2008
(DOY 259/0900z-260/0900z)
OBSERVATIONS SCHEDULED
ACS/SBC 11158
HST Imaging of UV Emission in Quiescent Early-type
Galaxies
We have constructed a sample of early type galaxies at
z~0.1 that have
blue UV-optical colors, yet also show no signs of optical
emission, or
extended blue light. We have cross-correlated the SDSS
catalog and the
Galaxy Evolution Explorer Medium Imaging Survey to select
a sample of
galaxies where this UV emission is strongest. The origin
of the UV
rising flux in these galaxies continues to be debated, and
the
possibility that some fraction of these galaxies may be
experiencing low
levels of star formation cannot be excluded. There is also
a possibility
that low level AGN activity {as evidenced by a point
source} is
responsible We propose to image the UV emission using the
HST/SBC and to
explore the morphology of the UV emission relative to the
optical light.
ACS/SBC WFPC2 11175
UV Imaging to Determine the Location of Residual Star
Formation in
Galaxies Recently Arrived on the Red Sequence
We have identified a sample of low-redshift {z = 0.04 -
0.10} galaxies
that are candidates for recent arrival on the red
sequence. They have
red optical colors indicative of old stellar populations,
but blue
UV-optical colors that could indicate the presence of a
small quantity
of continuing or very recent star formation. However,
their spectra lack
the emission lines that characterize star-forming
galaxies. We propose
to use ACS/SBC to obtain high-resolution imaging of the UV
flux in these
galaxies, in order to determine the spatial distribution
of the last
episode of star formation. WFPC2 imaging will provide B,
V, and I
photometry to measure the main stellar light distribution
of the galaxy
for comparison with the UV imaging, as well as to measure
color
gradients and the distribution of interstellar dust. This
detailed
morphological information will allow us to investigate the
hypothesis
that these galaxies have recently stopped forming stars
and to compare
the observed distribution of the last star formation with
predictions
for several different mechanisms that may quench star
formation in
galaxies.
FGS 11212
Filling the Period Gap for Massive Binaries
The current census of binaries among the massive O-type
stars is
seriously incomplete for systems in the period range from
years to
millennia because the radial velocity variations are too
small and the
angular separations too close for easy detection. Here we
propose to
discover binaries in this observational gap through a
Faint Guidance
Sensor SNAP survey of relatively bright targets listed in
the Galactic O
Star Catalog. Our primary goal is to determine the binary
frequency
among those in the cluster/association, field, and runaway
groups. The
results will help us assess the role of binaries in
massive star
formation and in the processes that lead to the ejection
of massive
stars from their natal clusters. The program will also
lead to the
identification of new, close binaries that will be targets
of long term
spectroscopic and high angular resolution observations to
determine
their masses and distances. The results will also be
important for the
interpretation of the spectra of suspected and newly
identified binary
and multiple systems.
FGS 11213
Distances to Eclipsing M Dwarf Binaries
We propose HST FGS observations to measure accurate
distances of 5
nearby M dwarf eclipsing binary systems, from which
model-independent
luminosities can be calculated. These objects have either
poor or no
existing parallax measurements. FGS parallax determinations
for these
systems, with their existing dynamic masses determined to
better than
0.5%, would serve as model-independent anchor points for
the low-mass
end of the mass-luminosity diagram.
FLIGHT OPERATIONS SUMMARY:
Significant Spacecraft Anomalies: (The following are
preliminary reports
of potential non-nominal performance that will be
investigated.)
HSTARS:
11493 - NCC safed during Restart
at
259/20:17:02z while executing Ops Request #18286-0 "NCS Restart and
Cooldown" step #10, NCS PCE On to Circulator On, due to exceeding the
maximum circulator speed limit. Status Buffer Message EXEC 908 P=200
T=8371 was received. Per SE request the 8051 memory was dumped.
11494 - NCC safed after restart
at
259/23:57:14z while executing Ops Request #18289-1. Status Buffer
Message EXEC 908 P=200 T=48531 was received. The 8051 memory was dumped.
COMPLETED OPS REQUEST:
18286-0 NCS Restart and Cooldown (Execution Failed)
@ 259/20:17z
18289-1 NCS Restart and Cooldown (Execution Failed) @
259/23:57z
COMPLETED OPS NOTES: (None)
SCHEDULED
SUCCESSFUL
FGS GSacq
12
12
FGS REacq 01
01
OBAD with Maneuver
26
26
SIGNIFICANT EVENTS:
NCS Restart operations unsuccessful
Upon execution of circulator start up commanding (Ops
Request 18286), a
NSCC-1 Status Buffer Message indicated that the circulator
was shut down
and the NCC was safed due to exceeding the maximum
circulator speed
limit of 1396 rps (Device Table 120). A memory dump is in
progress.
Flash Report: DOY 259 - 2nd NCS Restart Attempt.
Following circulatorstart up via Ops Request 18289 and
approximately 20
minutes of circulator runtime, a NSSC-1 Status Buffer
Message indicated
that the circulator was shut down and the NCC was safed
due to exceeding
the maximum circulator current limit of 150mA (Device
Table 251). A
memory dump of the start-up is in progress, history buffer
of the safing
event is not available.
The CPL start-up heater was commanded back on at
260/00:24:46