NASA Hubble Space Telescope Daily Report #3990

HUBBLE SPACE TELESCOPE – Continuing to collect World Class Science

DAILY REPORT # 3990

PERIOD COVERED: UT November 16, 2005 (DOY 320)

OBSERVATIONS SCHEDULED

ACS/HRC 10549

SAINTS – Supernova 1987A INTensive Survey

SAINTS is a program to observe SN 1987A, the brightest supernova in 384 years, as it morphs into the youngest supernova remnant at age 18. HST is the unique and perfect tool for spatially- resolved observations of the many physical components of SN 1987A. A violent encounter is underway between the fastest-moving debris and the circumstellar ring, exciting hotspots seen with HST that are suddenly lighting up. The optical and X-ray flux from the ring are both rising rapidly: HST and Chandra observations taken together are needed to understand the physics of these shocked regions. In Cycle14, the hotspots may fuse as the shock fully enters the ring. Photons from these shocks may excite previously hidden gas outside the ring, revealing the true extent of the mass loss that preceded the explosion. The inner debris of the explosion itself, still excited by radioactive isotopes produced in the explosion, is now well resolved by ACS and seen to be aspherical, providing direct clues to the mechanism of the explosion. Our search for a compact remnant is beginning to eliminate some theoretical possibilities and we have the opportunity in Cycle 14 to place much more stringent limits with NICMOS. Many questions about SN 1987A remain unanswered. How did the enigmatic three rings form in the late stages of Sanduleak -69 202? Precisely what took place in the center during the core collapse and bounce? Is a black hole or a neutron star left behind in the debris? SAINTS has been a continuous program since HST was launched– we propose to extend this rich and deep data set for present use and future reference to answer these central questions in the science of supernovae.

ACS/HRC 10738

Earth Flats

Sky flats will be obtained by observing the bright Earth with the HRC and WFC. These observations will be used to verify the accuracy of the flats currently in the pipeline and to monitor any changes. Weekly coronagraphic monitoring is required to assess the changing position of the spots.

ACS/HRC/WFC 10514

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 a Snapshot program using the ACS/HRC that has a potential discovery efficiency an order of magnitude higher than the HST observations that have already discovered the majority of known transneptunian binaries. By more than doubling the number of observed objects in dynamically hot and cold subpopulations we will be able to answer, with statistical significance, the question of whether these groups differ in the abundance of binaries as a result 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.

ACS/HRC/WFC 10729

ACS CCDs daily monitor

This program consists of a set of basic tests to monitor, the read noise, the development of hot pixels and test for any source of noise in ACS CCD detectors. The files, biases and dark will be used to create reference files for science calibration. This programme will be for the entire lifetime of ACS. Changes from cycle 13:- The default gain for WFC is 2 e-/DN. As before bias frames will be collected for both gain 1 and gain 2. Dark frames are acquired using the default gain {2}. This program cover the period Oct, 2 2005- May, 29-2006. The second half of the program has a different proposal number: 10758.

ACS/WFC 10491

A Snapshot Survey of the most massive clusters of galaxies

We propose a snapshot survey of a sample of 124 high X-ray luminosity clusters in the redshift range 0.3-0.7. Similarly luminous clusters at these redshifts frequently exhibit strong gravitational lensing. The proposed observations will provide important constraints on the nature of the cluster mass distributions and a set of optically bright, lensed galaxies for further 8-10m spectroscopy. We acknowledge the broad community interest in this sample and waive our data rights for these observations.

ACS/WFC 10526

Dynamics of the Polarization Structure of the Crab Nebula

The Crab Nebula is not a free expansion SNR. Rather, it is a pulsar wind nebula expanding from the inside out into a larger remnant of freely expanding ejecta. At the heart of this object is the Crab Pulsar and the region where the pulsar’s highly nonisotropic wind interacts with the larger synchtron nebula. HST and Chandra monitoring has shown this to be one of the most intricately structured and highly dynamical objects ever observed. In Cycle 12 we demonstrated our ability to use the polarization capabilities of the ACS to isolate physically discrete features within the Crab Synchrotron Nebula and accurately measure their polarization characteristics. These data provide a unique look at the physical structure in the heart of the Crab, adding a new dimension to past observations. Polarization provides extensive information about field geometries, the degree of disorder in the field, and particle pitch angle distributions. But one image of the Crab is like a single image of waves at the beach. It necessarily misses the point. In the Crab, the name of the game is “dynamics”. In this proposal we request time to monitor changes in the polarization structure of the Crab. This program will allow us to follow the changing polarization of features including relativistically moving wisps in the Crab Nebula. This is the only place in the sky where a dynamic relativistic plasma can be observed in sufficient detail to make such measurements possible, and the HST/ACS is the only instrument that we are likely to see in our careers capable of making the measurement. These observations will be an important addition to the already rich observational legacy of HST for what is arguably the most important single object in astrophysics.

ACS/WFC/NIC3 10541

Probing the jet mattter content of quasar PKS 0637-752

The matter content {electron-proton vs electron-positron composition} of extragalactic jets remains unknown, despite over three decades of work. Here, we propose NICMOS/NIC3 and ACS observations of the Chandra-detected, one sided jet of the superluminal quasar PKS 0637- 752 to derive the jet matter content by measuring the component of the Cosmic Microwave Background {CMB} radiation that is bulk-Comptonized {BC} by the cold electrons in the relativistically flowing large scale jet. What makes this source particularly suited for this procedure, is the absence of significant non-thermal jet emission from the ‘bridge’, the region between the core and the first bright knot WK7.8, guaranteeing that most of the electrons in the bridge are cold, leaving the BC scattered CMB radiation as the only significant source of photons in this region. The proposed NICMOS and ACS observations of the knot WK7.8 will provide spectral information in the IR-UV regime, which, together with existing multiwavelength data, will be used to derive the jet Doppler factor and minimum power necessary to power the knot emission as a function of the jet matter content. These will in turn be used to deduce, or strongly constrain, the actual jet matter content through comparison with the proposed NICMOS observations of the BC ‘bridge’ emission.

FGS 10610

Astrometric Masses of Extrasolar Planets and Brown Dwarfs

We propose observations with HST/FGS to estimate the astrometric elements {perturbation orbit semi-major axis and inclination} of extra-solar planets orbiting six stars. These companions were originally detected by radial velocity techniques. We have demonstrated that FGS astrometry of even a short segment of reflex motion, when combined with extensive radial velocity information, can yield useful inclination information {McArthur et al. 2004}, allowing us to determine companion masses. Extrasolar planet masses assist in two ongoing research frontiers. First, they provide useful boundary conditions for models of planetary formation and evolution of planetary systems. Second, knowing that a star in fact has a plantary mass companion, increases the value of that system to future extrasolar planet observation missions such as SIM PlanetQuest, TPF, and GAIA.

NICMOS 8790

NICMOS Post-SAA calibration – CR Persistence Part 1.

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.

WFPC2 10481

HST Observations of Astrophysically Important Visual Binaries

This is a continuation of a project begun in Cycle 7 and continued up through Cycle 11. The program consists of annual or biannual WFPC2 or FGS observations of three visual binary stars that will ultimately yield fundamental astrophysical results, once their orbits and masses are determined. Our targets are the following: {1} Procyon {P = 41 yr}, for which our first WFPC2 images yielded an extremely accurate angular separation of the bright F star and its much fainter white-dwarf companion. Combined with ground-based astrometry of the bright star, our observation significantly revised downward the derived masses, and brought Procyon A into excellent agreement with theoretical evolutionary tracks for the first time. With the continued monitoring proposed here, we will obtain masses to an accuracy of better than 1%, providing a testbed for theories of both Sun-like stars and white dwarfs. {2} G 107-70, a close double white dwarf {P = 19 yr} that promises to add two accurate masses to the tiny handful of white-dwarf masses that are directly known from dynamical measurements. {3} Mu Cas {P = 21 yr}, a famous metal-deficient G dwarf for which accurate masses will lead to the stars’ helium contents, with cosmological implications.

FLIGHT OPERATIONS SUMMARY:

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

HSTARS: (None)

COMPLETED OPS REQUEST: (None)

COMPLETED OPS NOTES: (None)

                         SCHEDULED    SUCCESSFUL
FGS GSacq                  10          10
FGS REacq                  03          03
OBAD with Maneuver     26          26
LOSS of LOCK

SIGNIFICANT EVENTS: (None)

-Lynn

Lynn F. Bassford
CHAMP HST Missions Operations Manager
Lockheed Martin Technical Operations
GSFC PH#: 301-286-2876
STScI PH#: 410-338-4895 (shared)