NASA Hubble Space Telescope Daily Report # 4536

HUBBLE SPACE TELESCOPE DAILY REPORT # 4536

Continuing to collect World Class Science

PERIOD COVERED: UT January 29, 2008 (DOY 029)

OBSERVATIONS SCHEDULED

FGS 11078

HST/FGS 1-Gyro On-Orbit Checkout

This proposal uses an FGS as an astrometer to observe bright stars (V<12) in Position mode, with the two other FGSs operating as guiders. The data obtained by the astrometer will be used to "witness" the pointing performance of the Observatory in FineLock under 1-gyro operations. Each visit of this proposal will have a single Pos mode exposure, the duration of which is to be set by target visibility or by other tests being conducted in parallel or in sequence with this proposal. For planning purposes this proposal specifies an exposure time of 40 minutes, but this can be adjusted as needed.

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/NIC2/NIC3 8795

NICMOS Post-SAA calibration – CR Persistence Part 6

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 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 i mages. Each observation will need its own CRMAP, as different SAA passages leave different imprints on the NICMOS detectors.

S/C 11345

HST/PCS 1-Gyro On-orbit Checkout

This proposal contains the part of the on-orbit test that cannot be satisfied by the science proposals. This includes testing certain M1G, T1G and F1G capabilities that could potentially compromise any science data collection, but are needed to validate the rebustness of 1-gyro science mode.

WFPC2 11077

HST/WFPC2 1-gyro On-orbit Checkout

The goal of this program is to verify the performance of the HST under One Gyro operation.

As in previous Two Gyro Testing and Orbital Verification programs the analysis will be done by characterizing the Point Spread Function (PSF) of PC1 in the F555W filter.

Two Primary issues addressed by this proposal: – PSF structure and repeatability – Pointing, stability, and offset accuracy.

PSF will be characterized as a function of – exposure time – guide star brightness – sky position

For the Pointing we will characterize: – repeatability of small offsets – stability within visibility period – stability across occultations. as a function of the guide star brightness

The Program requires fifteen orbits: (7 for the main target, 1 for the secondary target) for two gyro mode, then for 1-gyro mode. The structure of the visits is identical to the visits executed as part of the program 10458 “ACS and WFPC2 TGSMOV Two-Gyro PSF, Pointing, and Dither Test” with the only exception of the NICMOS parallel that have been removed.

The target selection is based on the visibility in the mid January to mid February 2008 timeframe. Final target selection will be confirmed after the analysis of the guide star availability.

WFPC2 11079

Treasury Imaging of Star Forming Regions in the Local Group: Complementing the GALEX and NOAO Surveys

We propose to use WFPC2 to image the most interesting star-forming regions in the Local Group galaxies, to resolve their young stellar populations. We will use a set of filters including F170W, which is critical to detect and characterize the most massive stars, to whose hot temperatures colors at longer wavelengths are not sensitive. WFPC2’s field of view ideally matches the typical size of the star-forming regions, and its spatial resolution allows us to measure individual stars, given the proximity of these galaxies. The resulting H-R diagrams will enable studies of star-formation properties in these regions, which cover largely differing metallicities {a factor of 17, compared to the factor of 4 explored so far} and characteristics. The results will further our understanding of the star-formation process, of the interplay between massive stars and environment, the properties of dust, and will provide the key to interpret integrated measurements of star-formation indicators {UV, IR, Halpha} available for several hundreds more distant galaxies. Our recent deep surveys of these galaxies with GALEX {FUV, NUV} and ground-based imaging {UBVRI, Halpha, [OIII] and [SII]} provided the identification of the most relevant SF sites. In addition to our scientific analysis, we will provide catalogs of HST photometry in 6 bands, matched corollary ground-based data, and UV, Halpha and IR integrated measurements of the associations, for comparison of integrated star-formation indices to the resolved populations. We envisage an EPO component.

WFPC2 11234

A Brief Revisit of the Crab

We propose using WFPC2 to obtain continuum-dominated images of the Crab pulsar and environs closely duplicating archival exposures from 1994 and 1995. By matching the archival data we can realize ~3mas precision astrometry with a minimum of systematic effects over a maximum {~13.5y} baseline. This determines the Crab proper motion to better than 0.3mas/yr {3km/s} accuracy and measures its position angle to better than 1.5degrees, i.e. reducing the errors of the best present {HST archive} measurement by a factor of three. Most importantly, this provide a nearly systematic-free result. This proper motion measurement would match the precision of the CXO-measured angular momentum vector. Comparison of these vectors is the foundation of an effort to understand the physical origin of the large momentum kick at pulsar birth.

FLIGHT OPERATIONS SUMMARY:

Significant Spacecraft Anomalies: (The following are preliminary reports of potential non-nominal performance that will be investigated.)

HSTARS: 11164 – On January 19, GSAcq(1,3,3) required multiple attempts for CT-DV OTA SE review of PTAS processing reviews that GSAcq(1,3,3) at 019:09:37:54.000 required multiple attempts to achieve CT-DV on FGS1. The acquisition was successful.

COMPLETED OPS REQUEST: 18181-3 – Setup for OGS/KFSP OOT

18188-1 – FHST Map to configure FHST slots A & B

18054-0 – Preview KF Sun Vector Data via Telemetry Diags

COMPLETED OPS NOTES: 1631-1 – Configure new KF Safemode Test to Disable

1665-0 – ODSGYRL limit for OGS/KFSP on orbit-test

1667-1 – Temp Limit Change for FHST Target Suppress for OGS OOT

                          SCHEDULED      SUCCESSFUL
FGS GSacq                 10                 10
FGS REacq                 01                 01 
OBAD with Maneuver        22                 22

SIGNIFICANT EVENTS:

Flash Report – Day 1 One Gyro Science (OGS) /Kalman Filer Sun Point (KFSP) OOT

At 29/08:56, commanding began for the OGS/KFSP on-orbit test with Ops Request 18181-3. Ops Request loaded the OGS and KFSP macros and configured for Universal Kalman Filter operation. Ops request 18182-4 was started containing the script for the test execution. The transition to the OGS SMS took place at 029/10:00. HST was transitioned to One Gyro mode at 29/10:34. The initial orbits were in M1G mode at a benign attitude. The first transition to T1G mode took place at 29/12:03. First pair of OBADs were executed at 29/12:06 and 12:14. Performance appeared nominal with analysis on-going.

The first OGS guide star acquisition was performed starting at 029/17:03 during a ZOE interval. Telemetry at AOS indicated that the acquisition succeeded. F1G fine lock was maintained until the scheduled termination at 029/18:09. Initial assessment of pointing performance indicates a 1-sigma telescope pointing jitter of approximately 4 milliarcseconds for this F1G interval.