Daily # 4104

HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

DAILY REPORT # 4104

PERIOD COVERED: UT May 01, 2006 (DOY 121)

OBSERVATIONS SCHEDULED

ACS/HRC/WFC 10487

A Search for Debris Disks in the Coeval Beta Pictoris Moving Group

Resolved observations of debris disks present us with the opportunity
of studying planetary evolution in other solar systems. We propose to
search for debris disks in the Beta Pictoris moving group {8-20 Myrs,
10-50 pc away} , which provides a coeval sample of multiple spectral
types, and it has already produced two magnificent resolved debris
disks: AU Mic and Beta Pic. Such coeval sample will provide us with a
snapshop of the crucial time in disk evolution in which the disk makes
the transition from optically thick to optically thin, and it will be
useful to study the stellar mass dependence of the disk evolution.

ACS/HRC/WFC 10514

Kuiper Belt Binaries: Probes of Early Solar System Evolution

Binaries in the Kuiper Belt are a scientific windfall: in them we have
relatively fragile test particles which can be used as tracers of the
early dynamical evolution of the outer Solar System. We propose a
Snapshot program using the ACS/HRC that has a potential discovery
efficiency an order of magnitude higher than the HST observations that
have already discovered the majority of known transneptunian binaries.
By more than doubling the number of observed objects in dynamically
hot and cold subpopulations we will be able to answer, with
statistical significance, the question of whether these groups differ
in the abundance of binaries as a result of their particular dynamical
paths into the Kuiper Belt. Today's Kuiper Belt bears the imprints of
the final stages of giant-planet building and migration; binaries may
offer some of the best preserved evidence of that long-ago era.

ACS/HRC/WFC 10734

ACS CCD Flash Calibration

This activity provides a set of CCD FLASH exposure reference images
for each current level/shutter-side/detector combination, for the pair
of FLASH LEDs on the instrument side currently in use. It also tests
the short-term repeatability at the shortest FLASH exposure times that
are expected to be used {1.0 sec}.

ACS/HRC/WFC 10758

ACS CCDs daily monitor

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. Changes from cycle 13:- The default
gain for WFC is 2 e-/DN. As before bias frames will be collected for
both gain 1 and gain 2. Dark frames are acquired using the default
gain {2}. This program cover the period May, 31 2006- Oct, 1-2006. The
first half of the program has a different proposal number: 10729.

ACS/SBC 10568

Ultraviolet spectrum of the binary millisecond pulsar J0437-4715

PSR J0437-4715 is the nearest and the brightest millisecond {recycled}
pulsar, and the only one detected at near-optical wavelengths. We
detected it with the HST STIS/FUV-MAMA detector and found that its FUV
spectrum is consistent with being emitted from the neutron star
surface with a temperature of about 0.1 MK, surprisingly high for such
an old object. We also found evidence of an emission line at 1372 A,
tentatively interpreted as a Zeeman component of the hydrogen Ly-alpha
line in a magnetic field of 700 MG. Unfortunately, the spectrum was
imaged in a region of strong detector background, which strongly
hampered the spectral analyses. We propose to re-observe the pulsar
with the ACS/SBC in FUV and ACS/HRC in NUV to obtain the spectrum of
the pulsar in a broad UV range. The spectral analysis will allow us to
measure the temperature of the full neutron star surface and probe the
heating mechanisms operating in old neutron stars. Confirmation of the
spectral line would lead to a first direct measuremnt of the magnetic
field and the radius of a spin-powered neutron star and uniquely
constrain the equation of state of superdense matter. The NUV spectrum
will also probe the magnetospheric emission and the thermal structure
of the cool white dwarf companion.

ACS/WFC 10775

An ACS Survey of Galactic Globular Clusters

We propose to conduct an ACS/WFC imaging survey of Galactic globular
clusters. We will construct the most extensive and deepest set of
photometry and astrometry to-date for these systems reaching a main
sequence mass of ~0.2 solar mass with S/N = 10. We will combine these
data with archival WFPC2 and STIS images to determine proper motions
for the stars in our fields. The resultant cleaned cluster CMDs will
allow us to study a variety of scientific questions. These include
[but are not limited to] 1} the determination of cluster ages and
distances 2} the construction of main sequence mass functions and the
issue of mass segregation 3} the internal motions and dynamical
evolution of globular clusters, and 4} absolute cluster motions,
orbits, and the Milky Way gravitational potential. We anticipate that
the unique resource provided by the proposed treasury archive will
play a central role in the field of globular cluster studies for
decades, with a stature comparable to that of the Hubble Deep Field
for high redshift studies.

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.

NICS3 10754

Spectrophotometric Standards for Cross-Observatory Calibration

This program will obtain NICMOS spectrophotometry of four main
sequence A stars and four K giants, each selected from the Spitzer
IRAC photometric calibration target and/or candidate calibration
target lists. These observations will supplement existing HST
observations of DA white dwarfs and solar analogs, and will provide a
broad base of stellar types for spectrophotometric cross calibration
of HST, Spitzer, and eventually JWST. The targets are chosen to be
faint enough for unsaturated observations with JWST NIRSPEC, yet still
bright enough for high signal to noise in relatively short
observations with HST+NICMOS and with Spitzer+IRAC.

WFPC2 10748

WFPC2 CYCLE 14 Standard Darks

This dark calibration program obtains dark frames every week in order
to provide data for the ongoing calibration of the CCD dark current
rate, and to monitor and characterize the evolution of hot pixels.
Over an extended period these data will also provide a monitor of
radiation damage to the CCDs.

WFPC2 10751

WFPC2 CYCLE 14 Intflat Linearity Check and Filter Rotation Anomaly
Monitor

Intflat observations will be taken to provide a linearity check: the
linearity test consists of a series of intflats in F555W, in each gain
and each shutter. A combination of intflats, visflats, and earthflats
will be used to check the repeatability of filter wheel motions.
{Intflat sequences tied to decons, visits 1-18 in prop 10363, have
been moved to the cycle 14 decon proposal 10744 for easier
scheduling.} Note: long-exposure WFPC2 intflats must be scheduled
during ACS anneals to prevent stray light from the WFPC2 lamps from
contaminating long ACS external exposures.

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 08 08
FGS REacq 02 02
OBAD with Maneuver 20 20

SIGNIFICANT EVENTS: (None)