NASA Hubble Space Telescope Daily Report # 3872
HUBBLE SPACE TELESCOPE – Continuing to collect World Class Science
DAILY REPORT # 3872
PERIOD COVERED: DOY 152
OBSERVATIONS SCHEDULED
ACS/HRC 10377
ACS Earth Flats
High signal sky flats will be obtained by observing the bright Earth
with the HRC and WFC. These observations will be used to verify the
accuracy of the flats currently used by the pipeline and will provide
a comparison with flats derived via other techniques: L-flats from
stellar observations, sky flats from stacked GO observations, and
internal flats using the calibration lamps. Weekly coronagraphic
monitoring is required to assess the changing position of the spots.
ACS/HRC/WFC 10389
ACS CCDs daily monitor – Cycle 13 – Part 2
This program consists of a set of basic tests to monitor, the read
noise, the development of hot pixels and test for any source of noise
in ACS CCD detectors. The files, biases and dark will be used to
create reference files for science calibration. This programme will be
for the entire lifetime of ACS.
ACS/HRC/WFC 10399
Accurate and Robust Calibration of the Extragalactic Distance Scale
with the Maser Galaxy NGC4258 II
The extragalactic distance scale {EDS} is defined by a comparison of
Cepheid Period-Luminosity {PL} relations for nearby galaxies and the
LMC, whose uncertain distance is thereby the SOLE anchor. Studies of
masers orbiting the central black hole in NGC4258 have provided the
most accurate extragalactic distance ever {7.2+/-0.5 Mpc}, and new
radio data and analysis techniques will reduce the uncertainty to <
3.5% {0.07 mag} by 2005. Since this distance is well determined and
based on geometric arguments, NGC4258 can provide a much needed new
anchor for the EDS. Ultimately, the combination of an independent
measurement of H0 and measurements of CMB fluctuations {e.g., WMAP}
can be used to directly constrain cosmological parameters including
the equation of state of dark energy. In our Cycle 12 proposal, we
defined a program spanning two cycles. The Cycle 12 portion was
accepted. We have acquired WFC images and are constructing well
sampled PL relations in 3 colors {BVI}. The purpose of the Cycle 13
observations is to address systematic sources of error and is crucial
for the success of the entire program. To disentangle the effects of
reddening and metallicity, and to characterize the effects of
blending, we require 50 orbits to obtain H-band photometry
{NICMOS/NIC2} and high resolution images {ACS/HRC}.
ACS/WFC 10361
Earth Flats
This proposal monitors flatfield stability. This proposal obtains
sequences of Earth streak flats to construct high quality flat fields
for the WFPC2 filter set. These flat fields will allow mapping of the
OTA illumination pattern and will be used in conjunction with previous
internal and external flats to generate new pipeline superflats. These
Earth flats will complement the Earth flat data obtained during cycles
4-12.
FGS 10610
Astrometric Masses of Extrasolar Planets and Brown Dwarfs
We propose observations with HST/FGS to estimate the astrometric
elements {perturbation orbit semi-major axis and inclination} of
extra-solar planets orbiting six stars. These companions were
originally detected by radial velocity techniques. We have
demonstrated that FGS astrometry of even a short segment of reflex
motion, when combined with extensive radial velocity information, can
yield useful inclination information {McArthur et al. 2004}, allowing
us to determine companion masses. Extrasolar planet masses assist in
two ongoing research frontiers. First, they provide useful boundary
conditions for models of planetary formation and evolution of
planetary systems. Second, knowing that a star in fact has a plantary
mass companion, increases the value of that system to future
extrasolar planet observation missions such as SIM PlanetQuest, TPF,
and GAIA.
NIC3/WFPC2/ACS/WFC 10131
Determining the Origin of Virgo’s Intracluster Stars
Intracluster stars constitute about 20% of the total stellar
population of a typical galaxy cluster, and their existence provides a
vital clue for our understanding of cluster formation and evolution.
However, to exploit their probative value, we need to know their
origins: are they the remnants of dwarf galaxies, long since destroyed
by the cluster potential, or have the stars been harassed from their
parent galaxies at recent epochs? To answer this question, we propose
to use the Wide-Field Channel of ACS to make an I, {V-I}
color-magnitude diagram of Virgo’s intracluster stars. From the
position and morphology of the population’s red giant branch, we will
be able to determine the metallicity distribution function of the
stars, and thereby determine their likely origin and ejection
mechanisms. Only HST with the ACS has the sensitivity and resolution
to perform this fundamental measurement. This program has two options.
Option one uses conventional methods of cluster photometry and
requires 37 orbits of exposure time. Option two involves a novel
analysis technique, which promises to achieve most of the same science
in two- thirds the time {23 orbits}. We describe this alternative
method of analysis and demonstrate its use via simulations.
NICMOS 8790
NICMOS Post-SAA calibration – CR Persistence Part 1.
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.
NICMOS 8791
NICMOS Post-SAA calibration – CR Persistence Part 2
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.
WFPC2 10363
WFPC2 CYCLE 13 Intflat and Visflat Sweeps and Filter Rotation Anomaly
Monitor
Using intflat observations, this WFPC2 proposal is designed to monitor
the pixel-to- pixel flatfield response and provide a linearity check.
The intflat sequences, to be done once during the year, are similar to
those from the Cycle 12 program 10075. The images will provide a
backup database as well as allow monitoring of the gain ratios. The
sweep is a complete set of internal flats, cycling through both
shutter blades and both gains. The linearity test consists of a series
of intflats in F555W, in each gain and each shutter. As in Cycle 12,
we plan to continue to take extra visflat, intflat, and earthflat
exposures to test the repeatability of filter wheel motions.
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)
17440-0 – Null Genslew for Proposal 10431- Slot 11 @ 152/14:10:00z
COMPLETED OPS NOTES: (None)
1322-1 – Adjust NICMOS Limits @ 152/1819z
1303-3 – Limit Adjustment for Structure Current Anomaly @ 152/1825z
SCHEDULED SUCCESSFUL FAILURE TIMES FGS Gsacq 07 07 FGS Reacq 07 07 FHST Update 10 10 LOSS of LOCK
SIGNIFICANT EVENTS: (None)
