Status Report

NASA Hubble Space Telescope Daily Report #4361

By SpaceRef Editor
May 14, 2007
Filed under , ,
NASA Hubble Space Telescope Daily Report #4361

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.


– Continuing to collect World Class Science

PERIOD COVERED: UT May 11,12,13, 2007 (DOY 131,132,133)


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 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.

NIC3 11072

Measuring the Physical Properties of the first two WASP transiting extrasolar planets

We have recently discovered the first two transiting extrasolar planets from the Wide Angle Search for Planets {WASP} project and confirmed both as planets using SOPHIE radial velocity measurements. Both WASP-1b and WASP-2b orbit about stars brighter than V=3D12, and are thus ideal =
targets for HST followup. WASP-1b is probably inflated in a manner similar to HD209458b but is in a closer orbit about the parent, which itself is the earliest-type parent star yet announced for a transiting extrasolar planet. At 0.03 AU from the parent star, WASP-2b is close to the minimum separation at which planets of this mass range are thought to survive. We request DD observations of WASP-1b and WASP- 2b, to constrain the masses and radii of both objects to a precision of a few tenths of a percent. Both parent stars have very similar brightnesses to the TrES-1 parent star, thus we will achieve equivalent photometric precision to previous successful observations of TrES-1b. As all further physical investigations {such as interior heating} depend on precise mass- and radius-determinations, this investigation is the essential next step in uncovering the physical characteristics of these planets and their parent stars. We have requested 12 orbits, though 9 orbits would provide the minimum acceptable coverage for our program. The consortium will formally announce the discoveries of WASP-1b and WASP-2b on Tuesday 26th September 2006. We ask that all material in this proposal be kept confidential until that date. We can supply the discovery paper on request after this date.

NIC1 11063

NICMOS Focus Monitoring

This program is a version of the standard focus sweep used since cycle 7. It has been modified to go deeper and uses more narrow filters for improved focus determination. For Cycle14 a new source has been added in order to accomodate 2-gyro mode: the open cluster NGC1850. The old target, the open cluster NGC3603, will be used whenever available and the new target used to fill the periods when NGC3603 is not visible. Steps: a} Use refined target field positions as determined from cycle 7 calibrations b} Use MULTIACCUM sequences of sufficient dynamic range to account for defocus c} Do a 17- point focus sweep, +/- 8mm about the PAM mechanical zeropoint for each cameras 1 and 2, in 1.0mm steps. d} Use PAM X/Y tilt and OTA offset slew compensations refined from previous focus monitoring/optical alignment activities

FGS 11019

Monitoring FGS1r’s Interferometric Response as a Function of Spectral Color

This proosal uses FGS1r in Transfer mode to observe standard single stars of a variety of spectral types to obtain point source interferograms for the Transfer mode calibration library. In specific cases, the calibration star will also be observed in POS mode multiple times with the F583W and F5ND elements to provide the data to verify the stabiligy of the cross filter calibration.

ACS/SBC 10907

New Sightlines for the Study of Intergalactic Helium: A Dozen High-Confidence, UV-Bright Quasars from SDSS/GALEX

The reionization of intergalactic helium is thought to have occurred between redshifts of about 3 and 4. Detailed study of HeII Lyman-alpha absorption toward a handful quasars at 2.73.1 quasars potentially suitable for HeII studies. We have cross-correlated SDSS quasars with GALEX UV sources to obtain a dozen new, very high-confidence, candidate quasars/sightlines {z=3D3.1 to 4.1} =
potentially useful for detailed HeII studies even with current HST instruments. We propose brief, 2-orbit per target, reconnaissance spectral exposures with the ACS SBC prism to definitively verify UV flux down to the HeII break. Our combined SDSS/GALEX selection insures a very high-yield of confirmations, as the quasars are already known to be UV-bright from broadband GALEX images. The additional sightlines, extending to very high-redshift, will directly enable ensemble spectral stacks, as well as long exposure follow-up spectra, at high S/N with the ACS/SBC ultraviolet prisms {or perhaps STIS or COS later}, to confidently measure the spectrum and evolution of the ionizing background radiation, the evolution of HeII opacity, and the density of intergalactic baryons.

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.

WFPC2 10880

The host galaxies of QSO2s: AGN feeding and evolution at high luminosities

Now that the presence of supermassive black holes in the nuclei of galaxies is a well established fact, other questions related to the AGN phenomena still have to be answered. Problems of particular interest are how the AGN gets fed, how the black hole evolves and how the evolution of the black hole is related to the evolution of the galaxy bulge. Here we propose to address some of these issues using ACS/WFC + F775W snapshot images of 73 QSO2s with redshifts in the range 0.3 WFPC2 10877

A Snapshot Survey of the Sites of Recent, Nearby Supernovae

During the past few years, robotic {or nearly robotic} searches for supernovae {SNe}, most notably our Lick Observatory Supernova Search {LOSS}, have found hundreds of SNe, many of them in quite nearby galaxies {cz < 4000 km/s}. Most of the objects were discovered before maximum brightness, and have follow-up photometry and spectroscopy; they include some of the best-studied SNe to date. We propose to conduct a snapshot imaging survey of the sites of some of these nearby objects, to obtain late-time photometry that {through the shape of the light and color curves} will help reveal the origin of their lingering energy. The images will also provide high-resolution information on the local environments of SNe that are far superior to what we can procure from the ground. For example, we will obtain color-color and color-magnitude diagrams of stars in these SN sites, to determine the SN progenitor masses and constraints on the reddening. Recovery of the SNe in the new HST images will also allow us to actually pinpoint their progenitor stars in cases where pre- explosion images exist in the HST archive. This proposal is an extension of our successful Cycle 13 snapshot survey with ACS. It is complementary to our Cycle 15 archival proposal, which is a continuation of our long-standing program to use existing HST images to glean information about SN environments.

WFPC2 10867

SAINTS – Supernova 1987A INTensive Survey

SAINTS is a program to observe SN 1987A, the brightest supernova in 383 years, as it morphs into the youngest supernova remnant at age 19. HST is a unique tool for spatially- resolved observations of the many physical components of SN 1987A. A violent encounter is now underway between the fastest-moving debris and the circumstellar ring: the collision excites “hotspots” that light up suddenly. The optical, infrared and X-ray fluxes are rising rapidly and vary significantly on 6-month time scales: regularly-spaced HST, SPITZER, and CHANDRA observations are needed to understand the physics of these shocked regions. In Cycle 15, the many separate hotspots may begin to fuse as the shock fully enters the circumstellar ring. Photons from these shocks may excite previously invisible gas outside the ring, revealing the true extent of the mass loss that preceded the explosion of Sanduleak -69 202. The inner debris of the explosion itself, still excited by radioactive isotopes produced in the explosion, is now resolved by ACS and seen to be aspherical, providing direct evidence on the asymmetry of the explosion. Many questions about SN 1987A remain unanswered despite our diligent efforts at observation and analysis since the launch of HST. How did the enigmatic three rings form? Precisely what took place in the core during the core collapse and bounce? Is a black hole or a neutron star left behind in the debris? The rich and deep data set from SAINTS will be a resource for current use and for future reference to help answer these central questions of supernova science.

ACS/SBC 10862

Comprehensive Auroral Imaging of Jupiter and Saturn during the International Heliophysical Year

A comprehensive set of observations of the auroral emissions from Jupiter and Saturn is proposed for the International Heliophysical Year in 2007, a unique period of especially concentrated measurements of space physics phenomena throughout the solar system. We propose to determine the physical relationship of the various auroral processes at Jupiter and Saturn with conditions in the solar wind at each planet. This can be accomplished with campaigns of observations, with a sampling interval not to exceed one day, covering at least one solar rotation. The solar wind plasma density approaching Jupiter will be measured by the New Horizons spacecraft, and a separate campaign near opposition in May 2007 will determine the effect of large-scale variations in the interplanetary magnetic field {IMF} on the Jovian aurora by extrapolation from near-Earth solar wind measurements. A similar Saturn campaign near opposition in Jan. 2007 will combine extrapolated solar wind data with measurements from a wide range of locations within the Saturn magnetosphere by Cassini. In the course of making these observations, it will be possible to fully map the auroral footprints of Io and the other satellites to determine both the local magnetic field geometry and the controlling factors in the electromagnetic interaction of each satellite with the corotating magnetic field and plasma density. Also in the course of making these observations, the auroral emission properties will be compared with the properties of the near-IR ionospheric emissions {from ground-based observations} and non thermal radio emissions, from ground-based observations for Jupiter?s decametric radiation and Cassini plasma wave measurements of the Saturn Kilometric Radiation {SKR}.

WFPC2 10832

Solving the microlensing puzzle: An HST high-resolution imaging approach

We propose to use the HST Advanced Camera for Surveys High Resolution Channel to obtain high resolution imaging data for 10 bona-fide LMC microlensing events seen in the original MACHO survey. The purpose of this survey will be to assess whether or not the lens and source stars have separated enough to be resolved since the original microlensing event took place – about a decade has passed since the original MACHO survey and the HST WFPC2 follow-up observations of the microlensing events. If the components of the lensing event are resolved, we will determine the apparent magnitude and color of both the lens and the source stars. These data, in combination with Spitzer/IRAC data and Magellan near-IR JHK data, will be used to ascertain the basic properties of the lens stars. With the majority of the microlensing events in the original MACHO survey observed at the highest spatial resolution currently possible, we will be able to draw important conclusions as to what fraction of these events have lenses which belong to some population of dwarf stars in the disk and what fraction must be due to lenses in the halo or beyond. These data will greatly increase our understanding of the structure of the Galaxy by characterizing the stellar population responsible for the gravitational microlensing.

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.

WFPC2 10786

Rotational state and composition of Pluto’s outer satellites

We propose an intricate set of observations aimed at discovering the rotational state of the newly discovered satellites of Pluto, S/2005 P1 and S/2005 P2. These observations will indicate if the satellites are in synchronous rotation or not. If they are not, then the observations will determine the rotational period or provide tight constraints on the amplitude. The other primary goal is to extend the wavelength coverage of the colors of the surface and allow us to constrain the surface compositions of both objects. From these data we will also be able to significantly improve the orbits of P1 and P2, improve the measurement of the bulk density of Charon, and search for albedo changes on the surface of Pluto.

WFPC2 10782

Quit winking: Jupiter opens its other eye

This week {March 6} a new red spot on Jupiter was announced, dubbed “Red Spot Jr.” by the press. It appears to be White Oval BA, the remanant of the three White Ovals that merged during 1998-2000. The new spot is deep red like the Great Red Spot {GRS} rather than bright white as were the ovals. We believe that the color change of the oval from white to red is indicative of a temperature change, as predicted by one of us in a Nature paper in 2004. The goal of our proposed observations is to test our theory of jovian climate change through observations of dynamical features of Red Spot Jr. and its surroundings, which provide indirect measurements of changes in the temperature and stratification of the jovian weather layer.


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

HSTARS: 10809 – GSACQ(2,1,2) failed GSACQ (2,1,2) at 133/12:18:16 failed to RGA control at 12:22:47 with QF2STOPF and QSTOP flags set. REACQ (2,1,2) at 13:53:16 also
failed at 13:57:00.

                       SCHEDULED      SUCCESSFUL

FGS GSacq               24                  23

FGS REacq               14                  13

OBAD with Maneuver      76                  76


Evaluation of Universal Kalman Filter performance continued. Details follow.

Background Kalman Filter Operation Flash Report for day 131

The KF was halted at 131/16:20 (OR 18076-0). The filter was restarted at 131/16:24 during orbit day and during an M2G guiding interval. The filter was activated with MSS and Gyro2 sensor inputs enabled. The filter was activated during orbit day, during a vehicle slew, during an M2G guiding interval and during slow changing B-field. All UKF parameters showed nominal operation. The test was an MSS/Gyro2 Initialization test case during a slow changing B-field and during a vehicle slew (M_G2_IVS, Test #35).

The filter was reconfigured for MSS only input and restarted at 18:15 to provide a long baseline of MSS only performance.

SpaceRef staff editor.