NASA Hubble Space Telescope Daily Report #4359
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 DAILY REPORT # 4359
– Continuing to collect World Class Science
PERIOD COVERED: UT May 09, 2007 (DOY 129)
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 10879
A search for planetary-mass companions to the nearest L dwarfs – completing the survey
We propose to extend the most sensitive survey yet undertaken for very low-mass companions to ultracool dwarfs. We will use NICMOS to complete imaging of an all-sky sample of 87 L dwarfs in 80 systems within 20 parsecs of the Sun. The combination of infrared imaging and proximity allows us to search for companions with mass ratios q>0.25 at separations exceeding ~3 AU, while probing companions with q>0.5 at ~1.5 AU separation. This resolution is crucial, since no ultracool binaries are known in the field with separations exceeding 15 AU. Fifty L dwarfs from the 20-parsec sample have high- resolution imaging, primarily through our Cycle 13 HST proposal which identified six new binaries, including an L/T system. Here, we propose to target the remaining 30 dwarfs.
NIC1 10889
The Nature of the Halos and Thick Disks of Spiral Galaxies
We propose to resolve the extra-planar stellar populations of the thick disks and halos of seven nearby, massive, edge-on galaxies using ACS, NICMOS, and WFPC2 in parallel. These observations will provide accurate star counts and color-magnitude diagrams 1.5 magnitudes below the tip of the Red Giant Branch sampled along the two principal axes and one intermediate axis of each galaxy. We will measure the metallicity distribution functions and stellar density profiles from star counts down to very low average surface brightnesses, equivalent to ~32 V-mag per square arcsec. These observations will provide the definitive HST study of extra-planar stellar populations of spiral galaxies. Our targets cover a range in galaxy mass, luminosity, and morphology and as function of these galaxy properties we will provide: – The first systematic study of the radial and isophotal shapes of the diffuse stellar halos of spiral galaxies – The most detailed comparative study to date of thick disk morphologies and stellar populations – A comprehensive analysis of halo and thick disk metallicity distributions as a function of galaxy type and position within the galaxy. – A sensitive search for tidal streams – The first opportunity to directly relate globular cluster systems to their field stellar population We will use these fossil records of the galaxy assembly process preserved in the old stellar populations to test halo and thick disk formation models within the hierarchical galaxy formation scheme. We will test LambdaCDM predictions on sub-galactic scales, where it is difficult to test using CMB and galaxy redshift surveys, and where it faces its most serious difficulties.
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 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 11085
Europa in Eclipse: Tenuous Atmosphere, Electromagnetic Activity and Surface Luminescence HST Proposal 11085
We propose to image Europa during its orbital eclipse by Jupiter. This will form the basis of an investigation into the nature of the tenuous atmosphere, electromagnetic environment and surface material of Europa. We will compare the FUV oxygen line at 1356A to the optical line at 6300A and seek optical auroral hydrogen emission in Halpha. With broad continuum filters, we will search for optical emissions from other atmospheric constituents and for fluorescence of the surface material, arising from the very high level of incident energetic particle radiation. The high spatial resolution of ACS will allow us to fully resolve scales of interest and allow us to distinguish easily the different terrains on Europa’s surface. In particular we wish to compare luminesence in regions dominated by ice to those of potentially organic red material.
FLIGHT OPERATIONS SUMMARY:
Significant Spacecraft Anomalies: (The following are preliminary reports of potential non-nominal performance that will be investigated.)
HSTARS:
10804 – FHST OBAD Failure At AOS 130/05:07:49 OBAD #2 scheduled @ 130/04:40:15 had failed.
OBAD #1: Data unavailable due to LOS
OBAD #2: V1 31234.84, V2 -9674.28, V3 12657.23, RSS 35062.98
COMPLETED OPS REQUEST:
18077-2 – MSS/CSS Converged & Add Gyro1 input Test #34
18070-5 – MSS/CSS Add Gyro2 input Test #38 for SMS 127
18073-1 – PCS KF OOT Support
18054-0 – Preview KF Sun Vector Data via Telemetry Diags
17543-2 – Dump OBAD tables after failed OBAD (Generic)
COMPLETED OPS NOTES: (None)
SCHEDULED SUCCESSFUL FGS GSacq 11 11 FGS REacq 03 03 OBAD with Maneuver 28 27
SIGNIFICANT EVENTS:
Evaluation of Universal Kalman Filter performance continued. Multiple text segments were executed, all of them successfully. Details follow. Background Kalman Filter Operation Flash Report for day 129: The KF was halted at 129/14:38. The filter was restarted at 129/14:41 during orbit day and during an M2G guiding interval. The filter was activated with the MSS and Gyro1 sensor inputs enabled. The Gyro1 sensor input was removed from the converged filter at 16:22 during orbit day, in an M2G guiding interval with the vehicle inertially fixed and during a slow changing B-field. All UKF parameters showed nominal operation. The test was an MSS/CSS test case with the Gyro1 sensor input removed during a slow changing B-field and with the spacecraft inertially fixed (MC_G1_HNS, Test #34). The removal of the Gyro1 input configured the KF back to the desired KF configuration for this week. The activity above used the slot 1 TMDIAG at 129/16:21. The slot 1 TMDIAG was reset to monitor the V2 component of the KF estimated sun vector at 129/19:09.
The KF was halted at 129/17:20. The filter was restarted at 129/17:22 during orbit night and during an F2G guiding interval. The filter was activated with the MSS and CSS input enabled. The Gyro1 sensor input was added to the converged filter at 18:05 during orbit day, during a vehicle maneuver, during an M2G guiding interval and during a slow changing B-field. All UKF parameters showed nominal operation. The test was an MSS/CSS test case with the Gyro1 sensor input added during a slow changing B-field and during a vehicle maneuver (MC_G1_RVS, Test #28). The MSS only configuration of the KF was restored at 129/19:08.
