Daily Report #4932

HUBBLE SPACE TELESCOPE - Continuing to Collect World Class Science

DAILY REPORT #4932

PERIOD COVERED: 5am September 16 - 5am September 17, 2009 (DOY 259/09:00z-260/09:00z)

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 11997

FUV Internal/External Wavelength Scale Monitor

This program monitors the offsets between the wavelength scale set by
the internal wavecal versus that defined by absorption lines in
external targets. This is accomplished by observing two external
targets in the SMC: SK191 with G130M and G160M and Cl* NGC 330 ROB B37
with G140L (SK191 is too bright to be observed with G140L). The
cenwaves observed in this program are a subset of the ones used during
Cycle 17. Observing all cenwaves would require a considerably larger
number of orbits. Constraints on scheduling of each target are placed
so that each target is observed once every ~2-3 months. Observing the
two targets every month would also require a considerably larger
number of orbits.

COS/NUV 11896

NUV Spectroscopic Sensitivity Monitoring

The purpose of this proposal is to monitor sensitivity of each NUV
grating mode to detect any changes due to contamination or other
causes.

COS/NUV/FUV 11673

Dynamics in the Atmosphere of the Evaporating Planet HD189733b

With HST/STIS, we detected and characterized the upper atmosphere of
the extrasolar planet HD209458b, showing that the planet must be
evaporating at a rate of ~10^10 g/s in a "blow-off" mechanism.

More recently, using ACS we concluded that HD189733b is also
evaporating. However, because of the low resolution of the ACS prism
spectroscopy, the escape rate and mechanism are still to be
determined. This is one of the prime objectives of the present
proposal.

COS observations of the absorption line profile with 15 km/s
resolution will allow us to probe the dynamics of the escaping gas,
and therefore to determine the escape rate. Simultaneous observations
of the transit depth and spectral shape in several important lines
(not only HI, but also OI, CII and possibly NI) will constrain the
escape mechanism and allow us to distinguish between several
scenarios. The results will enlighten the physical phenomenons at work
in the exosphere of these extrasolar planets, and provide new
constraints for the modeling of the evaporation of hot-Jupiters.

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.

WFC3/ACS/IR 11600

Star Formation, Extinction, and Metallicity at 0.7z1.5: H-Alpha
Fluxes and Sizes from a Grism Survey of GOODS-N

The global star formation rate (SFR) is ~10x higher at z=1 than today.
This could be due to drastically elevated SFR in some fraction of
galaxies, such as mergers with central bursts, or a higher SFR across
the board. Either means that the conditions in z=1 star forming
galaxies could be quite different from local objects. The next step
beyond measuring the global SFR is to determine the dependence of SFR,
obscuration, metallicity, and size of the star-forming region on
galaxy mass and redshift. However, SFR indicators at z=1 typically
apply local calibrations for UV, [O II] and far-IR, and do not agree
with each other on a galaxy-by-galaxy basis. Extinction, metallicity,
and dust properties cause uncontrolled offsets in SFR calibrations.
The great missing link is Balmer H-alpha, the most sensitive probe of
SFR. We propose a slitless WFC3/G141 IR grism survey of GOODS-N, at 2
orbits/pointing. It will detect Ha+[N II] emission from 0.7z1.5, to
L(Ha) = 1.7 x 10^41 erg/sec at z=1, measuring H-alpha fluxes and sizes
for 600 galaxies, and a small number of higher-redshift emitters.
This will produce: an emission-line redshift survey unbiased by
magnitude and color selection; star formation rates as a function of
galaxy properties, e.g. stellar mass and morphology/mergers measured
by ACS; comparisons of SFRs from H-alpha to UV and far-IR indicators;
calibrations of line ratios of H-alpha to important nebular lines such
as [O II] and H-beta, measuring variations in metallicity and
extinction and their effect on SFR estimates; and the first
measurement of scale lengths of the H-alpha emitting, star-forming
region in a large sample of z~1 sources.

WFC3/UVIS 11650

Mutual Orbits, Colors, Masses, and Bulk Densities of 3 Cold Classical
Trans-Neptunian Binaries

Many Trans-Neptunian Objects (TNOs) have been found to be binary or
multiple systems. As in other astrophysical settings, Trans-Neptunian
Binaries (TNBs) offer uniquely valuable information. Their mutual
orbits allow the direct determination of their system masses, perhaps
the most fundamental physical quantity of any astronomical object.
Their frequency of occurrence and dynamical characteristics provide
clues to formation conditions and evolution scenarios affecting both
the binaries and their single neighbors. Combining masses with sizes,
bulk densities can be measured. Densities constrain bulk composition
and internal structure, key clues to TNO origins and evolution over
time. Several TNB bulk densities have been determined, hinting at
interesting trends. But none of them belongs to the Cold Classical
sub- population, the one group of TNOs with demonstrably distinct
physical characteristics. Two top-priority Spitzer programs will soon
observe and measure the sizes of 3 Cold Classical TNBs. This proposal
seeks to determine the mutual orbits and thus masses of these systems,
enabling computation of their densities.

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 11907

UVIS Cycle 17 Contamination Monitor

The UV throughput of WFC3 during Cycle 17 is monitored via weekly
standard star observations in a subset of key filters covering
200-600nm and F606W, F814W as controls on the red end. The data will
provide a measure of throughput levels as a function of time and
wavelength, allowing for detection of the presence of possible
contaminants.

WFC3/UVIS 11908

Cycle 17: UVIS Bowtie Monitor

Ground testing revealed an intermittent hysteresis type effect in the
UVIS detector (both CCDs) at the level of ~1%, lasting hours to days.
Initially found via an unexpected bowtie-shaped feature in flatfield
ratios, subsequent lab tests on similar e2v devices have since shown
that it is also present as simply an overall offset across the entire
CCD, i.e., a QE offset without any discernable pattern. These lab
tests have further revealed that overexposing the detector to count
levels several times full well fills the traps and effectively
neutralizes the bowtie. Each visit in this proposal acquires a set of
three 3x3 binned internal flatfields: the first unsaturated image will
be used to detect any bowtie, the second, highly exposed image will
neutralize the bowtie if it is present, and the final image will allow
for verification that the bowtie is gone.

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 9 9
FGS REAcq 8 8
OBAD with Maneuver 8 8

SIGNIFICANT EVENTS: (None)