Status Report

NASA Hubble Space Telescope Daily Report #4088

By SpaceRef Editor
April 10, 2006
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NASA Hubble Space Telescope Daily Report #4088

HUBBLE SPACE TELESCOPE – Continuing to collect World Class Science


PERIOD COVERED: UT April 07,08,09, 2006 (DOY 097.098,099)


NIC1/NIC2/NIC3 8793

NICMOS Post-SAA calibration – CR Persistence Part 4

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.

ACS/HRC 10783

Rapid Response: Jupiter’s White Oval Turns Red

In the late 1930s, bright white clouds expanded and encircled Jupiter’s southern hemisphere in a band near 33 degrees south planetographic latitude. As it cleared, the clouds collapsed into three large anticyclonic storms later named the White Ovals. These three storms were second in size only to the Great Red Spot, but unlike their larger counterpart, were covered with white clouds. In the mid to late 1990s these storms suddenly approached each other very closely, resulting in the 1998 merger of two of the storms. In 2000, the third oval also merged, leaving one remaining large White Oval. Early in 2006, amateur observers noted that the oval appeared to be changing in appearance and turning red. While small red spots do appear on Jupiter from time to time, they usually form as a colored spot, cloud over, and become white, rather than the opposite. We wish to observe this unexpected, and unprecedented, color change with ACS to compare to similar ACS observations that serendipitously observed the oval in January 2005 and to recent and upcoming ground-based observations. The ACS HRC observations would be the highest spatial resolution possible, while also offering a unique range of filters from the near UV to the near IR. Using the two ACS datasets, we will compare the vertical structure of the storm to determine how the mass loading of the clouds may have changed. This is useful in determining local energetics and dynamics, which play a strong role in the overall energy balance of the planet. Understanding these mechanisms on the giant planets will also help us to better model the atmospheres of unresolved extrasolar giant planets.

ACS/WFC 10775

An ACS Survey of Galactic Globular Clusters

We propose to conduct an ACS/WFC imaging survey of Galactic globular clusters. We will construct the most extensive and deepest set of photometry and astrometry to-date for these systems reaching a main sequence mass of ~0.2 solar mass with S/N >= 10. We will combine these data with archival WFPC2 and STIS images to determine proper motions for the stars in our fields. The resultant cleaned cluster CMDs will allow us to study a variety of scientific questions. These include [but are not limited to] 1} the determination of cluster ages and distances 2} the construction of main sequence mass functions and the issue of mass segregation 3} the internal motions and dynamical evolution of globular clusters, and 4} absolute cluster motions, orbits, and the Milky Way gravitational potential. We anticipate that the unique resource provided by the proposed treasury archive will play a central role in the field of globular cluster studies for decades, with a stature comparable to that of the Hubble Deep Field for high redshift studies.


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 May, 31 2006- Oct, 1-2006. The first half of the program has a different proposal number: 10729.

WFPC2 10749

Earth Flats

This proposal monitors flatfield stability. This proposal obtains sequences of Earth streak flats to construct high quality flat fields for the WFPC2 filter set. These flat fields will allow mapping of the OTA illumination pattern and will be used in conjuction with previous internal and external flats to generate new pipeline superflats. These Earth flats will complement the Earth flat data obtained during cycles 4-13.

ACS/WFC 10732

ACS internal CTE monitor

The charge transfer efficiency {CTE} of the ACS CCD detectors will decline as damage due to on-orbit radiation exposure accumulates. This degradation will be closely monitored at regular intervals, because it is likely to determine the useful lifetime of the CCDs. All the data for this program is acquired using internal targets {lamps} only, so all of the exposures should be taken during Earth occultation time {but not during SAA passages}. This program emulates the ACS pre-flight ground calibration and post-launch SMOV testing {program 8948}, so that results from each epoch can be directly compared. Extended Pixel Edge Response {EPER} and First Pixel Response {FPR} data will be obtained over a range of signal levels for both the Wide Field Channel {WFC}, and the High Resolution Channel {HRC}.

S/C 10718

The Exosphere of a Newly Discovered Transiting Planet

We propose to use HST to directly detect the atmosphere and extended envelope {exosphere} of a recently discovered planet that transits the relatively bright star HD 149026. Absorption of background stellar Lyman-alpha emission is an extremely sensitive exospheric diagnostic that only HST can measure. If the HD 149026 planet is evaporating, then hydrogen in the exosphere should fill or overfill the Roche lobe, which has a size 4 times the diameter of Jupiter. If we do not detect a decrease in Lyman-alpha flux during several transits, then the hydrogen exosphere does not fill the Roche lobe of the planet and significant evaporation is unlikely. This would be a surprise, given that Vidal-Madjar et al. {2003} detected the exosphere of the planet that transits HD 209458, and the models of Lecavelier des Etangs et al. {2004} predict an order of magnitude more evaporation for the planet around HD 149026, due to its lower mass and smaller orbital distance. The newly discovered planet has 3 times the mean density and at least 3 times the core mass of the planet that transits HD 209458, which is consistent with significant exospheric evaporation in the past. We will also use ACS/PR200L observations to measure stellar limb darkening in the NUV, to detect Mg in the lower atmosphere of the planet, and to search for evidence of a moon or planetary rings.

ACS/WFC 10615

Timing Studies of the X-ray Binary Populations in Globular Clusters

Close binaries are fundamental to the dynamical stability and evolution of globular clusters, but large populations have been extremely difficult to identify. Chandra X-ray images provide a revolutionary resource, revealing a few to dozens of low-luminosity X-ray sources in every cluster deeply examined; our own Chandra programs uniformly study these ubiquitous X-ray sources {close binaries and their progeny} in a dozen clusters. We have obtained multicolor, single-epoch, ACS images, from which to obtain initial optical counterparts, especially CVs {the dominant population in most clusters}, BY Dra’s, and qLMXBs. As HST capability for follow-on, confirming, spectra of our multicolor-selected counterparts is now severely curtailed, we propose an ACS time-series imaging program that will yield equivalent follow-on information for 5 of our clusters. The proposed ACS time-series data with 6 min resolution and 8 hr time-span, will: provide variability information to secure our suggested multicolor identifications; allow secure classifications of the various X-ray subpopulations {e.g., CVs vs. BY Dra’s}; yield quality lightcurves, whose shape will help test the notion that magnetic CVs are more common in globular clusters than the field; and, provide interesting contraints on the period distributions of cluster X-ray binaries.

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.

ACS/WFC 10592

An ACS Survey of a Complete Sample of Luminous Infrared Galaxies in the Local Universe

At luminosities above 10^11.4 L_sun, the space density of far-infrared selected galaxies exceeds that of optically selected galaxies. These `luminous infrared galaxies’ {LIRGs} are primarily interacting or merging disk galaxies undergoing enhanced star formation and Active Galactic Nuclei {AGN} activity, possibly triggered as the objects transform into massive S0 and elliptical merger remnants. We propose ACS/WFC imaging of a complete sample of 88 L_IR > 10^11.4 L_sun luminous infrared galaxies in the IRAS Revised Bright Galaxy Sample {RBGS: i.e., 60 micron flux density > 5.24 Jy}. This sample is ideal not only in its completeness and sample size, but also in the proximity and brightness of the galaxies. The superb sensitivity, resolution, and field of view of ACS/WFC on HST enables a unique opportunity to study the detailed structure of galaxies that sample all stages of the merger process. Imaging will be done with the F439W and F814W filters {B and I-band} to examine as a function of both luminosity and merger state {i} the evidence at optical wavelengths of star formation and AGN activity and the manner in which instabilities {bars and bridges} in the galaxies may funnel material to these active regions, {ii} the relationship between star formation and AGN activity, and {iii} the structural properties {AGN, bulge, and disk components} and fundamental parameters {effective radius and surface brightness} of LIRGs and their similarity with putative evolutionary byproducts {elliptical, S0 and classical AGN host galaxies}. This HST survey will also bridge the wavelength gap between a Spitzer imaging survey {covering seven bands in the 3.6-160 micron range} and a GALEX UV imaging survey of these galaxies, but will resolve complexes of star clusters and multiple nuclei at resolutions well beyond the capabilities of either Spitzer or GALEX. The combined datasets will result in the most comprehensive multiwavelength study of interacting and merging galaxies to date.

ACS/WFC 10587

Measuring the Mass Dependence of Early-Type Galaxy Structure

We propose two-color ACS-WFC Snapshot observations of a sample of 118 candidate early- type gravitational lens galaxies. Our lens-candidate sample is selected to yield {in combination with earlier results} an approximately uniform final distribution of 40 early-type strong lenses across a wide range of masses, with velocity dispersions {a dynamical proxy for mass} ranging from 125 to 300 km/s. The proposed program will deliver the first significant sample of low-mass gravitational lenses. All of our candidates have known lens and source redshifts from Sloan Digital Sky Survey data, and all are bright enough to permit detailed photometric and stellar- dynamical observation. We will constrain the luminous and dark-matter mass profiles of confirmed lenses using lensed-image geometry and lens-galaxy structural/photometric measurements from HST imaging in combination with dynamical measurements from spatially resolved ground-based follow-up spectroscopy. Hence we will determine, in unprecedented detail, the dependence of early-type galaxy mass structure and mass-to-light ratio upon galaxy mass. These results will allow us to directly test theoretical predictions for halo concentration and star-formation efficiency as a function of mass and for the existence of a cuspy inner dark- matter component, and will illuminate the structural explanation behind the fundamental plane of early-type galaxies. The lens-candidate selection and confirmation strategy that we propose has been proven successful for high-mass galaxies by our Cycle 13 Snapshot program {10174}. The program that we propose here will produce a complementary and unprecedented lens sample spanning a wide range of lens-galaxy masses.

ACS/HRC 10559

Astrometric monitoring of binary L and T dwarfs

We propose to obtain high angular resolution ACS images of five binary L and T dwarfs in order to determine their orbital parameters and dynamical masses, and directly constrain the evolutionary models of ultracool and substellar objects. The binaries have estimated periods ranging between 5 and 14 years. All of them have already been resolved at least twice {sometimes more} using HST, providing first and second epochs measurements. We propose to obtain two more ACS imaging observations separated by 9 to 12 months during cycle 14. The expected period coverage should therefore range between 35% and 117%, allowing us to compute precise orbital parameters and masses. Our sample is large enough and covers a sufficiently wide range of spectral types {from L3 to T5.5} to allow us to obtain strong constraints the evolutionnary models.

ACS/HRC 10545

Icy planetoids of the outer solar system

Early HST studies of satellites of Kuiper belt object focussed on the 50-200 km objects that were the largest known at the time. In the past 3 years we have discovered a population of much more rare and much larger {500-2000+ km} icy planetoids in the Kuiper belt. These objects are the largest and brightest known in the Kuiper belt and, in the era when we now know of more than 1000 Kuiper belt objects, these few planetoids are likely to be the focus of much of the research on physical properties of the outer solar system for years to come. We are currently engaged in an intensive program involving Spitzer, Keck, and other telescopes to study the physical and dynamical properties of this new population. HST is uniquely capable of addressing one parameter fundamental to completing the physical picture of these planetoids: the existence and size of any satellites. The detection and characterization of satellites to these large planetoids would allow us to address unique issues critical to the formation and evolution of the outer solar system, including the measurement of densities, internal properties, sizes and shapes of these objects, the study of binary formation as a function of primary size, and the context of the Pluto-Charon binary. For these bright objects, a satellite search takes less than a full orbit, allowing the opportunity for a new project on UV spectroscopy of the planetoids to piggyback at no added time cost. This poorly explored spectral range has the potential to show unique signatures of trapped gasses, cosmochemically important ices, and complex organic materials.

NIC2 10519

Testing the Stellar Coalescence and Accretion Disk Theories of Massive Star Formation with NICMOS

The importance of massive stars cannot be underestimated – they produce most of the heavy elements in the universe and dominate the evolution of the interstellar medium in their vicinity. In spite of their significance, our understanding of their formation is meager. Both accretion through disks, analogous to the process of low-mass star formation, and coalescence of low-mass stars through collisions in the dense cores of stellar clusters have been suggested. Possibly both mechanisms occur. High spatial resolution polarization measurements of the closest massive young stellar objects {YSOs} will enable us to search for evidence of disk accretion or coalescence in the form of patterns indicative of light scattered off a coherent disk or off a disk disrupted by an infalling star, respectively. Here we propose to use 2 micron polarimetry with NICMOS to identify the presence of accretion disks around massive YSOs or to characterize their environments as possibly disrupted from a close stellar encounter. There are only a few sources that meet the stringent selection criteria for this investigation {even with HST}, which we will examine here. High spatial resolution is required, but even more important, the point spread function {PSF} must be stable with time. Furthermore, the PSF must put minimal flux into large spatial scales, something that cannot be achieved with adaptive optics. This combination of high Strehl ratio and stable PSF can only be achieved from space.


A Search for Debris Disks in the Coeval Beta Pictoris Moving Group

Resolved observations of debris disks present us with the opportunity of studying planetary evolution in other solar systems. We propose to search for debris disks in the Beta Pictoris moving group {8-20 Myrs, 10-50 pc away} , which provides a coeval sample of multiple spectral types, and it has already produced two magnificent resolved debris disks: AU Mic and Beta Pic. Such coeval sample will provide us with a snapshop of the crucial time in disk evolution in which the disk makes the transition from optically thick to optically thin, and it will be useful to study the stellar mass dependence of the disk evolution.

ACS/HRC 10474

Shooting Stars: Looking for Direct Evidence of Massive Central Black Holes in Globular Clusters

We propose to make observations that directly test the proposition that globular clusters contain massive black holes. Our targets are the bulge globular clusters NGC 6388 and NGC 6441. These are probably among the most massive in the galaxy, but are understudied compared to more familiar objects such as M15. Our analysis suggests that these two clusters are the most likely to show unambiguous evidence for a central massive black hole if such things exist in globular clusters. The observations proposed will give us the first thorough kinematic and photometric studies of these two clusters. The combination of the two epochs will give us proper motions good to of order 6 km/s. In addition, they will provide us with the first good, deep, color-magnitude diagrams for these clusters. These diagrams will be used to investigate the make up of the stellar population in the clusters, to more firmly establish their distances, ages, and metallicities, and to search for a binary sequence.

ACS/HRC 10350

X-ray Binaries in the Ultrahigh Collision Rate Globular Cluster NGC 6388

We propose a joint Chandra-HST study of the massive, high density globular cluster NGC 6388 to study its large expected populations of quiescent low-mass X-ray binaries {qLMXBs} and bright cataclysmic variables {CVs}, and to test for the presence of an intermediate-mass black hole {IMBH}. NGC 6388 has the highest predicted X-ray binary production rate of any Galactic cluster. The qLMXBs will be used to constrain neutron star accretion models, and neutron star masses and radii. The CVs will be used to investigate the effects of cluster structure, metallicity, initial binary fraction, and dynamical history on accreting binary populations. The proposed 3 orbits of HST U-band imaging would complement deep HST V and I-band imaging, already in-hand, for identifying Chandra sources.


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


10206 – ReAcq Failure @ 099/08:53:33z

Guide star REACQ(1,3,3) at 08:46:43 failed to acquire fine lock. QDVFGSM0 (FGS Attitude Error Angle) broke limit at 08:53:33 with a value of -0.000734776 radians or 151 arc seconds. Primary GSACQ at 07:15:27 was successful.

10208 – OBAD Failure @ 099/07:25:37z

OBAD on day 099/07:22:39 with FHST 2 and 3 failed with very high reported error correction (129128.96, -57933.86, 94842.73, RSS= 170369.48). Status Buffer message 1902 “OBAD Failed Identification” was received at 07:25:37.


  • 17689-0 – Battery 6 Capacity Test Script & Battery Pressure Limit COP @ 097/1536z
  • 17691-0 – Restoration of Battery Pressure Limits After BCT @ 097/1542z
  • 17695-2 – Monitor VehConLaw.Integral Path Data via TMDIAG Slot 0 @ 097/1545z
  • 17700-0 – Filter ESBs 1201 and 1202 @ 097/1758z
  • 17701-0 – Null genslews for proposal 10625 – slots 1-7, 12, and 13 @ 097/2055z
  • 17688-1 – Set TCINIT to 4 – CANCELLED
  • 17690-0 – Battery 6 BCT Contingency Scripts – CANCELLED


                         SCHEDULED      SUCCESSFUL      FAILURE TIMES
FGS GSacq               21                     21
FGS REacq               21                     20                 (HSTAR 10206)
OBAD with Maneuver  84                     83                 (HSTAR 10208)


Flash Report- Final FLASH Report for Battery 6 Capacity Test – (EPS SE, Fri, 07 Apr 2006 16:35:28) – Battery 6 has sufficiently recovered from its discharge to 15 volts. At 097/1527 GMT, Battery 6 was placed back on-line in flight software. Deactivation of the Battery Capacity Taper Charge Macro was also executed at this time to return HST’s charging to its nominal Taper Charge scheme. The Benchmark SOC, SOC-1 and SOC-2 values were returned to their nominal, pre-test, 6-battery values. The EPS system is now back to its nominal configuration in both FSW and Hardware. The current integrated capacity for Battery 6 is 60.15 Ah @ 5 amp, (56.15 @ 9 amp).

SpaceRef staff editor.