Notice: Due to the conversion of some ACS WFC or HRC observations into

WFPC2, or NICMOS observations after the loss of ACS CCD science

capability in January, there may be an occasional discrepancy between a

proposal's listed (and correct) instrument usage and the abstract that

follows it.

HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

DAILY REPORT     # 4444

PERIOD COVERED: UT September 10, 2007 (DOY 253)

OBSERVATIONS SCHEDULED

ACS/SBC 10840

The FUV fluxes of Tauri stars in the Taurus molecular cloud

Present and forthcoming ground-based and space surveys of the T Tauri

stars in the Taurus molecular cloud will provide information from high

energy stellar and accretion radiation to low energy solid state and

molecular emission from the disk, making those stars perfect

laboratories to carry out self-consistent studies of disk physics and

evolution. We propose to complete this wealth of information by

obtaining ACS/FUV spectra for a significant sample of Taurus T Tauri

stars, covering a range of accretion properties and dust evolutionary

stages. FUV fluxes carry ~ 10 - 100 more energy than X-rays into these

disks and are thus crucial gas heating agents and key to disk dispersal

by photoevaporation. These observations are a pre-requisite to interpret

observations with Spitzer, SOFIA, Herschel, and ALMA, and will become

one of the important legacies of HST to the star formation community.

WFPC2 11024

WFPC2 CYCLE 15 INTERNAL MONITOR

This calibration proposal is the Cycle 15 routine internal monitor for

WFPC2, to be run weekly to monitor the health of the cameras. A variety

of internal exposures are obtained in order to provide a monitor of the

integrity of the CCD camera electronics in both bays {both gain 7 and

gain 15 -- to test stability of gains and bias levels}, a test for

quantum efficiency in the CCDs, and a monitor for possible buildup of

contaminants on the CCD windows. These also provide raw data for

generating annual super-bias reference files for the calibration

pipeline.

FGS 11212

Filling the Period Gap for Massive Binaries

The current census of binaries among the massive O-type stars is

seriously incomplete for systems in the period range from years to

millennia because the radial velocity variations are too small and the

angular separations too close for easy detection. Here we propose to

discover binaries in this observational gap through a Faint Guidance

Sensor SNAP survey of relatively bright targets listed in the Galactic O

Star Catalog. Our primary goal is to determine the binary frequency

among those in the cluster/association, field, and runaway groups. The

results will help us assess the role of binaries in massive star

formation and in the processes that lead to the ejection of massive

stars from their natal clusters. The program will also lead to the

identification of new, close binaries that will be targets of long term

spectroscopic and high angular resolution observations to determine

their masses and distances. The results will also be important for the

interpretation of the spectra of suspected and newly identified binary

and multiple systems.

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 DARKs. 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 11152

Probing the compact dust disk of a nearby Classical T Tauri Star

BP Psc is a high Galactic latitude {b = -57}, bright, IRAS source that

generally has been classified as a T Tauri star but little studied to

date. We have carried out a multiwavelength ground-based study of this

object and find that it is most likely a ~10 Myr classical T Tauri star

surrounded by a gas and dust disk, and less than 100 pc from Earth,

making it one of the oldest and closest such stars known. Near-IR AO

images and IR photometry show it is surrounded by an compact {0.2"},

almost-edge-on, optically thick disk of dust with a wide range of

temperatures. We propose a multiwavelength polarimetric study of the

compact disk to support quantitative modeling to recover disk and dust

parameters. We also propose coronagraphic imaging to search for

larger-scale dust structures invisible in ground-based images, and

narrowband imaging of an outflow jet and associated Herbig- Haro objects

to study their structure and determine a kinematic distance of the

system. A massive compact disk surrounding an isolated 10 Myr star is a

unique environment for planet formation, and its proximity to Earth

allows HST to study it in detail.

WFPC2 11023

WFPC2 CYCLE 15 Standard Darks - part 1

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 11081

RR Lyrae stars in M31 Globular Clusters: How did the M31 Spiral Galaxy

Form?

The pulsation properties of the RR Lyrae stars in the globular clusters

of the Andromeda galaxy {M31} have the potential to provide essential

insight on the first epoch of the galaxy formation and to trace the

merging episodes that led to the assembly of M31. Their mean periods

along with the cluster metallicities can provide an independent estimate

of the M31 cluster ages and, in turn, of the time scale of the M31 halo

formation, by comparison with their Milky Way counterparts. We will

observe RR Lyrae stars in 6 appropriately selected globular clusters of

M31 using WFPC2 to derive periods, light curves, and physical parameters

of these eyewitnesses of the first epochs of the M31 formation.

FLIGHT OPERATIONS SUMMARY:

Significant Spacecraft Anomalies: (The following are preliminary reports

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

HSTARS:

10989 - REAcq (2,1,1) failed to RGA Hold (Gyro Control)

           At 253/11:29:25 REAcq (2,1,1) scheduled from 253/11:26:13 - 11:33:48

           failed to RGA Hold (Gyro Control) after receiving a QSTOP flag on FGS 2.

           Mnemonics QF2STOPF, QSTOP, QF1SSDIF and QF2SSDIF all flagged out due to

           this failure.

           OBAD #1: V1 -996.75, V2 -1468.06, V3 570.40, RSS 1863.89

           OBAD #2: V1 6.61, V2 0.56, V3 -4.70, RSS 8.13

           OBAD MAP: Not scheduled

10990 - GSAcq (2,1,1) failed to RGA Hold (Gyro Control)

           GSAcq (2,1,1) failed to RGA Hold due to QSTOP flag on FGS 2. Mnemonics

           QF2STOPF, QSTOP, QF1SSDIF and QF2SSDIF all flagged out due to this

           failure. No 486 ESB messages were received. The star pair used in this

           acquisition is the same pair as used in HSTAR 10989.

           OBAD #1: Unavailable due to LOS

           OBAD #2: V1 7.23, V2 0.81, V3 -0.12, RSS 7.28

           OBAD MAP: V1 -4.81, V2 1.46, V3 3.62, RSS 6.20

COMPLETED OPS REQUEST: (None)

COMPLETED OPS NOTES: (None)

                       SCHEDULED      SUCCESSFUL  

FGS GSacq               06                  05                 

FGS REacq               09                  08           

OBAD with Maneuver 30                  30              

SIGNIFICANT EVENTS: (None)