NASA Hubble Space Telescope Daily Report #4444

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 DAILY REPORT #4444

– Continuing to collect World Class Science

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=3Ddate/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 =3D -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

                      SCHEDULED      SUCCESSFUL

FGS GSacq               06                  05
FGS REacq               09                  08
OBAD with Maneuver      30                  30

SIGNIFICANT EVENTS: (None)