Status Report

NASA Hubble Space Telescope Daily Report #4724

By SpaceRef Editor
October 29, 2008
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Continuing to collect World Class Science

PERIOD COVERED: 5am October 24 – 5am October 27, 2008 (DOY 298/0900z-301/0900z)


FGS 11901/11212

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.

WFPC2 11867

HH 30

This is a end-of-life WFPC2 imaging program of the disk and jet of the young star HH 30. HH 30 will be observed on PC1 in filters F555W, F675W, and F814W. Jet emission will be seen in F675W extending to the NNW. F555W and F814W each get one orbit of long exposures, and F675W gets two orbits to see the jet at large distances. The orientation is specified to ensure that the jet is not truncated by the chip edge and to place the nearby star XZ Tau in the far corner of WF2.

WFPC2 11796

WFPC2 Cycle 16 Decontaminations and Associated Observations

This proposal is for the WFPC2 decons. Also included are instrument monitors tied to decons: photometric stability check, focus monitor, pre- and post-decon internals (bias, intflats, kspots, & darks), UV throughput check, VISFLAT sweep, and internal UV flat check.

WFPC2 11793

WFPC2 Cycle 16 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.

WFPC2 11302

WFPC2 CYCLE 16 Standard Darks – Part III

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 11178

Probing Solar System History with Orbits, Masses, and Colors of Transneptunian Binaries

The recent discovery of numerous transneptunian binaries {TNBs} opens a window into dynamical conditions in the protoplanetary disk where they formed as well as the history of subsequent events which sculpted the outer Solar System and emplaced them onto their present day heliocentric orbits. To date, at least 47 TNBs have been discovered, but only about a dozen have had their mutual orbits and separate colors determined, frustrating their use to investigate numerous important scientific questions. The current shortage of data especially cripples scientific investigations requiring statistical comparisons among the ensemble characteristics. We propose to obtain sufficient astrometry and photometry of 23 TNBs to compute their mutual orbits and system masses and to determine separate primary and secondary colors, roughly tripling the sample for which this information is known, as well as extending it to include systems of two near-equal size bodies. To make the most efficient possible use of HST, we will use a Monte Carlo technique to optimally schedule our observations.


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


11553 – GSAcq (2,0,2) failed to RGA Hold

GSAcq (2,0,2) failed to RGA Hold at 300/09:52:26 due to QSTOP and QF2STOPF flags on FGS 2.

Observations affected: WFPC Proposal 11867, observations 19 – 20

11554 – REAcq (2,0,2) Loss of Lock while guiding

REAcq (2,0,2), scheduled @300/11:20:28z and 300/12:56:23z were successful. At 11:28:58z and13:05:43z, stop flag indications (QF2STOPF and QSTOP) were set on FGS 2. Loss of Lock occurred while guiding under FGS 2 and P4TAKDAT (Take Data Flag) went down. REAcq (2,0,2) scheduled @300/14:13:17z was in RGA Hold (Gyro Control) at AOS. The spacecraft was in T2G attitude hold mode. No 486 ESB messages or NSSC-1 STB messages were received.

Observations affected: WFPC2 Proposal #11867, #21-30.


18344-0 – Set NSSC-1 ATP for Science SMS Intercept @ 299/0717z


                         SCHEDULED      SUCCESSFUL      FAILURE

FGS GSacq                28                  27
FGS REacq                06                  05
OBAD with Maneuver       68                  68
LOSS of LOCK                                               3


Flash Report: WFPC2 Recovery Complete

The WFPC2 recovery via SMS is complete. The WFPC2 mechanisms recovery was performed. ROP NS-16 was executed to verify the RAM and PROM dumps. CCD Auto-erase was initiated, TEC power enabled, and TEC set-points were set via the SMS, completing ~299/19:41.

Science activity for WFPC2 resumes at 299/21:46 with a series of internal observations such as Bias and Internal Flats. The first external image is commanded at 299/22:57.

SpaceRef staff editor.