Daily Report #4755

HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

DAILY REPORT****** #4755

PERIOD COVERED: 5am December 11 - 5am December 12, 2008 (DOY
*************************** 346/1000z-347/1000z)

OBSERVATIONS SCHEDULED

ACS/SBC 11110

Searching for Lyman Apha Emission from FUSE Lyman Continuum
Candidates

We have recently been granted time on FUSE to characterize the escape
fraction of hydrogen Lyman continuum (Lyc) photons from a
morphologically diverse set of star forming galaxies. The FUSE program
is designed to provide ~ 5 sigma detections of Lyc photons emitted
from star forming galaxies with escape fractions ~5%. With this
proposal we seek hydrogen Lyman alpha (Lya) observations of a
representative subset of the FUSE program targets to constrain the
observational relationship between Lyc, Lya, and hydrogen Balmer line
emission in these systems. Such observations explore the detailed
balance between the simple optically thin (Case A) and optically thick
(Case B) limits in recombination theory. The ultimate goal of this
program is to quantify the relationship between escaping Lya and Lyc
emission and the first structures that form in the early universe.

FGS 11942

Increasing the Accuracy of HST Astrometry with FGS1R

We propose to observe six exoplanetary system host stars and two
planetary nebulae central stars with FGS1r. All objects have been
previously observed under proposals GO-09233, -09969, -10989, and
-11210. These observations will significantly extend the time
baseline, permitting improvements in the determination of proper
motion. This systematic motion must be removed to get at the
perturbation of interest, either due to exoplanetary companions or the
orbital motion of the Earth (parallax). In most cases the perturbation
orbits will also improve. We improve either companion mass or PN
parallax. For one target, GJ 876, theoretical dynamical modelers have
proposed an inclination closer to 50 degrees, while FGS3 measurements
indicated an inclination closer to 84 degrees. These new data, once
combined with our older FGS3 data, will permit an independent
remeasurement of the inclination of the outermost companion, and a
re-evaluation of widely used dynamical algorithms.

FGS 11943

Binaries at the Extremes of the H-R Diagram

We propose to use HST/Fine Guidance Sensor 1r to survey for binaries
among some of the most massive, least massive, and oldest stars in our
part of the Galaxy. FGS allows us to spatially resolve binary systems
that are too faint for ground-based, speckle or optical long baseline
interferometry, and too close to resolve with AO. We propose a
SNAP-style program of single orbit FGS TRANS mode observations of very
massive stars in the cluster NGC 3603, luminous blue variables, nearby
low mass main sequence stars, cool subdwarf stars, and white dwarfs.
These observations will help us to (1) identify systems suitable for
follow up studies for mass determination, (2) study the role of
binaries in stellar birth and in advanced evolutionary states, (3)
explore the fundamental properties of stars near the main
sequence-brown dwarf boundary, (4) understand the role of binaries for
X-ray bright systems, (5) find binaries among ancient and nearby
subdwarf stars, and (6) help calibrate the white dwarf mass - radius
relation.

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: (None)

COMPLETED OPS NOTES: (None)

*********************** SCHEDULED***** SUCCESSFUL

FGS GSacq************** 07***************** 07
FGS REacq************** 00***************** 00
OBAD with Maneuver **** 14***************** 14

SIGNIFICANT EVENTS:

FLASH Report:

The "final" expected NCS CPL Reservoir temperature setpoint adjustment
was commanded to +22 degC at 345/23:03:03 UTC.

Some initial signs of the onset of a flood condition were noted at
345/17:41:00 UTC following the setpoint increase to +20 degC, but the
loop stabilized nicely and has been able to sustain the additional
2-degree increase since that time. Since the initial Reservoir
setpoint change at 345/14:22:01 UTC, the Circulator Housing
temperature (MNCIHSGT) has increased 0.75 K from 279.66 K to 280.41
K.