Notice: For the foreseeable future, the daily reports may contain

apparent discrepancies between some proposal descriptions and the listed

instrument usage. This is due to the conversion of previously approved

ACS WFC or HRC observations into WFPC2, or NICMOS observations

subsequent to the loss of ACS CCD science capability in late January.

HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

DAILY REPORT       # 4360

PERIOD COVERED: UT May 10, 2007 (DOY 130)

OBSERVATIONS SCHEDULED

WFPC2  10800

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 to

continue a Snapshot program using the ACS/HRC that has a demonstrated

discovery potential an order of magnitude higher than the HST

observations that have already discovered the majority of known

transneptunian binaries. With this continuation we seek to reach the

original goals of this project: to accumulate a sufficiently large

sample in each of the distinct populations collected in the Kuiper Belt

to be able to measure, with statistical significance, how the fraction

of binaries varies as a function 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.

NIC1 11057

Cycle 15 NICMOS dark current, shading profile, and read noise monitoring

program

The purpose of this proposal is to monitor the dark current, read noise,

and shading profile for all three NICMOS detectors throughout the

duration of Cycle 15. This proposal is a slightly modified version of

proposal 10380 of cycle 13 and 9993 of cycle12 and is the same as Cycle

14. that we cut down some exposure time to make the observation fit

within 24 orbits.

NIC1/NIC2/NIC3 8794

NICMOS Post-SAA calibration - CR Persistence Part 5

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.

NIC2 10849

Imaging Scattered Light from Debris Disks Discovered by the Spitzer

Space Telescope around 21 Sun-like Stars

We propose to use the high-contrast capability of the NICMOS coronagraph

to image a sample of newly discovered circumstellar disks associated

with Sun-like stars. These systems were identified by their strong

thermal infrared {IR} emission with the Spitzer Space Telescope as part

of the Spitzer Legacy Science program titled "The Formation and

Evolution of Planetary Systems" {FEPS, P.I.: M.Meyer}. Modeling of the

thermal excess emission from the spectral energy distributions alone

cannot distinguish between narrowly confined high-opacity disks and

broadly distributed, low-opacity disks. By resolving light scattered by

the circumstellar material, our proposed NICMOS observations can break

this degeneracy, thus revealing the conditions under which planet

formation processes are occuring or have occured. For three of our

IR-excess stars that have known radial-velocity planets, resolved

imaging of the circumstellar debris disks may further offer an

unprecedented view of planet-disk interactions in an extrasolar

planetary system. Even non-detections of the light scattered by the

circumstellar material will place strong constraints on the disk

geometries, ruling out disk models with high optical depth. Unlike

previous disk imaging programs, our program contains a well-defined

sample of ~1 solar mass stars covering a range of ages from 3 Myr to 3

Gyr, thus allowing us to study the evolution of disks from primordial to

debris for the first time. The results from our program will greatly

improve our understanding of the architecture of debris disks around

Sun-like stars, and will create a morphological context for the

existence of our own solar system. This proposal is for a continuation

of an approved Cycle 14 program {GO/10527, P.I.: D. Hines}.

NIC2 10857

Are Organics Common in Outer Planetary Systems?

Mixtures of water ice and organics seem to pervade surfaces in the outer

Solar System, from the rings of Saturn to the Kuiper Belt Objects. The

early Earth was bombarded by the leftover planetesimals from the

formation of the planets, and these must have been rich in both ice and

carbon to provide the building blocks of life. Scattered light from

debris disks is remarkably similar in albedo {total scattering

efficiency} and color {red} to the objects in the outer solar system.

Thus, we have a hint that the same photochemical processes that happened

close to home also happen around other stars. We propose to study the

color of two debris disks in some detail. Scattering of light is the

only window available to us to see the composition of debris disks in a

spatially resolved manner and to assess their potential for containing

planets like ours.

WFPC2 10903

Resolving the LMC Microlensing Puzzle: Where are the Lensing Objects?

We are requesting 12 HST orbits to continue to investigate the nature of

the population that gives rise to the microlensing seen towards the LMC.

This proposal builds on the cycle 14 HST program {10583} and will

complement the study with 12 yet-to-be discovered microlensing

candidates from Fall 2006. Our SuperMacho project is an ongoing ground-

based survey on the CTIO 4m that has demonstrated the ability to detect

LMC microlensing events via frame subtraction. The combination of high

angular resolution and photometric accuracy with HST will allow us to 1}

confrim that the detected flux excursions arise from LMC stars, rather

than background supernovae or AGN, and 2} obtain reliable baseline flux

measurements for the objects in their unlensed state. This latter

measurement in important in determining the microlensing optical depth

towards the LMC.

FLIGHT OPERATIONS SUMMARY:

Significant Spacecraft Anomalies: (The following are preliminary reports

of potential non-nominal performance that will be investigated.)

HSTARS:

10805 - REacq(2,3,2) failed due to scan step limit exceeded

           The REacq(2,3,2) scheduled at 130/13:58:51 failed due to scan step limit

           exceeded on FGS 2. OBAD 2 before the REaqc showed errors of V1=1.59,

           V2=1.34, V3=9.72, and RSS=9.94.

COMPLETED OPS REQUEST: (None)

COMPLETED OPS NOTES: (None)

                      SCHEDULED      SUCCESSFUL   

FGS GSacq               09                 09               

FGS REacq               05                 04            

OBAD with Maneuver 28                 28              

SIGNIFICANT EVENTS:

Evaluation of Universal Kalman Filter performance continued. Details

follow.

Flash Report:  Background Kalman Filter Operation, Day 130

A Kalman filter performance test was executed from 130/16:10 to 16:55

per Ops Request 18071-3. The KF was initialized with CSS and MSS inputs

enabled at 130/16:10. Gyro 2 input to the KF was enabled at 16:28:30

under slow-changing B-field conditions during an M2G vehicle maneuver.

Gyro 2 input to the KF was disabled at 16:40 and CSS input was disabled

at 16:52, returning the KF to the pre-test MSS-only configuration.

Kalman filter convergence and operation during the test was nominal.