HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

 

DAILY REPORT       # 4516

 

PERIOD COVERED: UT December 28,29,30, 2007 (DOY 362,363,364)

 

OBSERVATIONS SCHEDULED

 

 

NIC1/NIC2/NIC3 8795

 

NICMOS Post-SAA calibration - CR Persistence Part 6

 

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 i

mages. Each observation will need its own CRMAP, as different SAA

passages leave different imprints on the NICMOS detectors.

 

S/C 11320

 

NICMOS Focus Monitoring Cycle 16

 

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. A new source was added in Cycle 14 in

order to accommodate 2-gyro mode: the open cluster NGC1850. This source

is part of the current proposal. 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. For NIC3 we step from -0.5mm

to -9.5mm relative to mechanical zero, in steps of 1.0mm. d) Use PAM X/Y

tilt and OTA offset slew compensations refined from previous focus

monitoring/optical alignment activities

 

ACS/SBC 11309

 

Chemical Composition of an Exo-Neptune

 

The recent discovery that the Neptune-like exoplanet GJ 436 b transits

its host star has presented us the first chance to observationally study

ice giant formation beyond our solar system {Gillon et al. 2007}. Using

Directors Discretionary time, we propose to obtain a high-precision

light curve of the GJ 436 b transit with the FGS in order to improve the

current radius determination for this planet. Measuring a precise radius

for GJ 436 b will allow us to ascertain whether the planet has a pure

water vapor or H/He envelope like Uranus and Neptune. Knowing this will

constrain its formation and evolution and help place our own solar

system ice giants in a broader context. Additionally, a precise radius

for GJ 436 b will be a necessity for interpreting the certain follow-up

observations of this unique system.

 

ACS/SBC 11220

 

Mapping the FUV Evolution of Type IIn Supernovae

 

We will use the PR110L prism on the SBC of ACS to map the FUV evolution

of Type IIn supernovae {SNe}. The main goal of this proposal is to

measure the FUV continuum, Ly-a emission line flux, and their evolution

to {1} quantify and interpret Type IIn SN transient event detections at

high redshift and {2} dramatically improve current high redshift Type

IIn selection criteria. We show that the inherent properties of Type IIn

SNe facilitate high redshift detection. We will observe the rest-frame

FUV of a sample of eight 0.02 < z < 0.33 Type IIn SNe to directly

measure the survival of Ly-alpha photons in low to intermediate redshift

Type IIn SNe environments and extrapolate the results to high redshift.

We will calibrate relationships such as FUV luminosity vs. emission line

flux and measure emission line evolution vs. FUV light evolution. The

intent is to categorize and improve the utility of Type IIn SNe.

 

WFPC2 11216

 

HST / Chandra Monitoring of a Dramatic Flare in the M87 Jet

 

As the nearest galaxy with an optical jet, M87 affords an unparalleled

opportunity to study extragalactic jet phenomena at the highest

resolution. During 2002, HST and Chandra monitoring of the M87 jet

detected a dramatic flare in knot HST-1 located ~1" from the nucleus.

Its optical brightness eventually increased seventy-fold and peaked in

2005; the X- rays show a similarly dramatic outburst. In both bands

HST-1 is still extremely bright and greatly outshines the galaxy

nucleus. To our knowledge this is the first incidence of an optical or

X-ray outburst from a jet region which is spatially distinct from the

core source -- this presents an unprecedented opportunity to study the

processes responsible for non- thermal variability and the X-ray

emission. We propose five epochs of HST/WFPC2 flux monitoring during

Cycle 16, as well as seven epochs of Chandra/ACIS observation {5ksec

each, six Chandra epochs contemporary with HST}. At two of the HST/WFPC2

epochs we also gather spectral information, and at one epoch we will map

the magnetic field structure. The results of this investigation are of

key importance not only for understanding the nature of the X-ray

emission of the M87 jet, but also for understanding flares in blazar

jets, which are highly variable, but where we have never before been

able to resolve the flaring region in the optical or X-rays. These new

observations will allow us to track the decay phase of the giant flare,

and study smaller secondary flares such as seen late in 2006. Ultimately

we will test synchrotron emission models for the X-ray outburst,

constrain particle acceleration and loss timescales, and study the jet

dynamics associated with this flaring component.

 

FGS 11210

 

The Architecture of Exoplanetary Systems

 

Are all planetary systems coplanar? Concordance cosmogony makes that

prediction. It is, however, a prediction of extrasolar planetary system

architecture as yet untested by direct observation for main sequence

stars other than the Sun. To provide such a test, we propose to carry

out FGS astrometric studies on four stars hosting seven companions. Our

understanding of the planet formation process will grow as we match not

only system architecture, but formed planet mass and true distance from

the primary with host star characteristics for a wide variety of host

stars and exoplanet masses. We propose that a series of FGS astrometric

observations with demonstrated 1 millisecond of arc per- observation

precision can establish the degree of coplanarity and component true

masses for four extrasolar systems: HD 202206 {brown dwarf+planet}; HD

128311 {planet+planet}, HD 160691 = mu Arae {planet+planet}, and HD

222404AB = gamma Cephei {planet+star}. In each case the companion is

identified as such by assuming that the minimum mass is the actual mass.

For the last target, a known stellar binary system, the companion orbit

is stable only if coplanar with the AB binary orbit.

 

WFPC2 11202

 

The Structure of Early-type Galaxies: 0.1-100 Effective Radii

 

The structure, formation and evolution of early-type galaxies is still

largely an open problem in cosmology: how does the Universe evolve from

large linear scales dominated by dark matter to the highly non-linear

scales of galaxies, where baryons and dark matter both play important,

interacting, roles? To understand the complex physical processes

involved in their formation scenario, and why they have the tight

scaling relations that we observe today {e.g. the Fundamental Plane}, it

is critically important not only to understand their stellar structure,

but also their dark-matter distribution from the smallest to the largest

scales. Over the last three years the SLACS collaboration has developed

a toolbox to tackle these issues in a unique and encompassing way by

combining new non-parametric strong lensing techniques, stellar

dynamics, and most recently weak gravitational lensing, with

high-quality Hubble Space Telescope imaging and VLT/Keck spectroscopic

data of early-type lens systems. This allows us to break degeneracies

that are inherent to each of these techniques separately and probe the

mass structure of early-type galaxies from 0.1 to 100 effective radii.

The large dynamic range to which lensing is sensitive allows us both to

probe the clumpy substructure of these galaxies, as well as their

low-density outer haloes. These methods have convincingly been

demonstrated, by our team, using smaller pilot-samples of SLACS lens

systems with HST data. In this proposal, we request observing time with

WFPC2 and NICMOS to observe 53 strong lens systems from SLACS, to obtain

complete multi-color imaging for each system. This would bring the total

number of SLACS lens systems to 87 with completed HST imaging and

effectively doubles the known number of galaxy-scale strong lenses. The

deep HST images enable us to fully exploit our new techniques, beat down

low-number statistics, and probe the structure and evolution of

early-type galaxies, not only with a uniform data-set an order of

magnitude larger than what is available now, but also with a fully

coherent and self-consistent methodological approach!

 

WFPC2 11201

 

Systemic and Internal motions of the Magellanic Clouds: Third Epoch

Images

 

In Cycles 11 and 13 we obtained two epochs of ACS/HRC data for fields in

the Magellanic Clouds centered on background quasars. We used these data

to determine the proper motions of the LMC and SMC to better than 5% and

15% respectively. These are by far the best determinations of the proper

motions of these two galaxies. The results have a number of unexpected

implications for the Milky Way-LMC-SMC system. The implied

three-dimensional velocities are larger than previously believed, and

are not much less than the escape velocity in a standard 10^12 solar

mass Milky Way dark halo. Orbit calculations suggest the Clouds may not

be bound to the Milky Way or may just be on their first passage, both of

which would be unexpected in view of traditional interpretations of the

Magellanic Stream. Alternatively, the Milky Way dark halo may be a

factor of two more massive than previously believed, which would be

surprising in view of other observational constraints. Also, the

relative velocity between the LMC and SMC is larger than expected,

leaving open the possibility that the Clouds may not be bound to each

other. To further verify and refine our results we now request an epoch

of WFPC2/PC data for the fields centered on 40 quasars that have at

least one epoch of ACS imaging. We request execution in snapshot mode,

as in our previous programs, to ensure the most efficient use of HST

resources. A third epoch of data of these fields will provide crucial

information to verify that there are no residual systematic effects in

our previous measurements. More importantly, it will increase the time

baseline from 2 to 5 yrs and will increase the number of fields with at

least two epochs of data. This will reduce our uncertainties

correspondingly, so that we can better address whether the Clouds are

indeed bound to each other and to the Milky Way. It will also allow us

to constrain the internal motions of various populations within the

Clouds, and will allow us to determine a distance to the LMC using

rotational parallax.

 

NIC3 11195

 

Morphologies of the Most Extreme High-Redshift Mid-IR-luminous Galaxies

II: The `Bump' Sources

 

The formative phase of some of the most massive galaxies may be

extremely luminous, characterized by intense star- and AGN-formation.

Till now, few such galaxies have been unambiguously identified at high

redshift, and thus far we have been restricted to studying the

low-redshift ultraluminous infrared galaxies as possible analogs. We

have recently discovered a sample of objects which may indeed represent

this early phase in galaxy formation, and are undertaking an extensive

multiwavelength study of this population. These objects are optically

extremely faint {R>26} but nevertheless bright at mid-infrared

wavelengths {F[24um] > 0.5 mJy}. Mid-infrared spectroscopy with

Spitzer/IRS reveals that they have redshifts z~2, implying luminosities

~1E13 Lsun. Their mid-IR SEDs fall into two broad, perhaps overlapping,

categories. Sources with brighter F[24um] exhibit power-law SEDs and SiO

absorption features in their mid-IR spectra characteristic of AGN,

whereas those with fainter F[24um] show a "bump" characteristic of the

redshifted 1.6um peak from a stellar population, and PAH emission

characteristic of starformation. We have begun obtaining HST images of

the brighter sources in Cycle 15 to obtain identifications and determine

kpc-scale morphologies for these galaxies. Here, we aim to target the

second class {the "bump" sources} with the goal of determining if these

constitute morphologically different objects, or simply a "low-AGN"

state of the brighter class. The proposed observations will help us

determine whether these objects are merging systems, massive obscured

starbursts {with obscuration on kpc scales!} or very reddened {locally

obscured} AGN hosted by intrinsically low-luminosity galaxies.

 

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.

 

ACS/SBC 11145

 

Probing the Planet Forming Region of T Tauri Stars in Chamaeleon

 

By studying the inner, planet-forming regions of circumstellar disks

around low-mass pre- main sequence stars we can refine theories of giant

planet formation and develop timescales for the evolution of disks and

their planets. Spitzer infrared observations of T Tauri stars in the

Chamaeleon star-forming region have given us an unprecedented look at

dust evolution in young objects. However, despite this ground breaking

progress in studying the dust in young disks, the gas properties of the

inner disk remain essentially unknown. Using ACS on HST, we propose to

measure the H_2 emission originating in the innermost disk regions of

classical T Tauri stars in different stages of evolution with the

objective of revealing the timescales of gas dissipation and its

relationship to dust evolution. This proposal is part of a comprehensive

effort with approved programs on Spitzer, Gemini, and Magellan that aim

to characterize the state of gas and dust in disks where planets may

already have formed.

 

WFPC2 11134

 

WFPC2 Tidal Tail Survey: Probing Star Cluster Formation on the Edge

 

The spectacular HST images of the interiors of merging galaxies such as

the Antennae and NGC 7252 have revealed rich and diverse populations of

star clusters created over the course of the interaction. Intriguingly,

our WFPC2 study of tidal tails in these and other interacting pairs has

shown that star cluster birth in the tails does not follow a similarly

straightforward evolution. In fact, cluster formation in these

relatively sparse environments is not guaranteed -- only one of six

tails in our initial study showed evidence for a significant population

of young star clusters. The tail environment thus offers the opportunity

to probe star cluster formation on the edge of the physical parameter

space {e.g., of stellar and gas mass, density, and pressure} that

permits it to occur. We propose to significantly extend our pilot sample

of optically bright, gas-rich tidal tails by a factor of 4 in number to

include a more diverse population of tails, encompassing major and minor

mergers, gas-rich and gas-poor tails, as well as early, late, and merged

interaction stages. With 21 orbits of HST WFPC2 imaging in the F606W and

F814W filters, we can identify, roughly age-date, and measure sizes of

star clusters to determine what physical parameters affect star cluster

formation. WFPC2 imaging has been used effectively in our initial study

of four mergers, and it will be possible in this program to reach

similar limits of Mv=-8.5 for each of 16 more tails. With the much

larger sample we expect to isolate which factors, such as merger stage,

HI content, and merger mass ratio, drive the formation of star clusters.

 

NIC3 11107

 

Imaging of Local Lyman Break Galaxy Analogs: New Clues to Galaxy

Formation in the Early Universe

 

We have used the ultraviolet all-sky imaging survey currently being

conducted by the Galaxy Evolution Explorer {GALEX} to identify for the

first time a rare population of low- redshift starbursts with properties

remarkably similar to high-redshift Lyman Break Galaxies {LBGs}. These

"compact UV luminous galaxies" {UVLGs} resemble LBGs in terms of size,

SFR, surface brightness, mass, metallicity, kinematics, dust, and color.

The UVLG sample offers the unique opportunity of investigating some very

important properties of LBGs that have remained virtually inaccessible

at high redshift: their morphology and the mechanism that drives their

star formation. Therefore, in Cycle 15 we have imaged 7 UVLGs using ACS

in order to 1} characterize their morphology and look for signs of

interactions and mergers, and 2} probe their star formation histories

over a variety of timescales. The images show a striking trend of

small-scale mergers turning large amounts of gas into vigorous

starbursts {a process referred to as dissipational or "wet" merging}.

Here, we propose to complete our sample of 31 LBG analogs using the

ACS/SBC F150LP {FUV} and WFPC2 F606W {R} filters in order to create a

statistical sample to study the mechanism that triggers star formation

in UVLGs and its implications for the nature of LBGs. Specifically, we

will 1} study the trend between galaxy merging and SFR in UVLGs, 2}

artificially redshift the FUV images to z=1-4 and compare morphologies

with those in similarly sized samples of LBGs at the same rest-frame

wavelengths in e.g. GOODS, UDF, and COSMOS, 3} determine the presence

and morphology of significant stellar mass in "pre-burst" stars, and 4}

study their immediate environment. Together with our Spitzer

{IRAC+MIPS}, GALEX, SDSS and radio data, the HST observations will form

a unique union of data that may for the first time shed light on how the

earliest major episodes of star formation in high redshift galaxies came

about. This proposal was adapted from an ACS HRC+WFC proposal to meet

the new Cycle 16 observing constraints, and can be carried out using the

ACS/SBC and WFPC2 without compromising our original science goals.

 

WFPC2 11103

 

A Snapshot Survey of The Most Massive Clusters of Galaxies

 

We propose the continuation of our highly successful SNAPshot survey of

a sample of 125 very X-ray luminous clusters in the redshift range

0.3-0.7. As demonstrated by the 25 snapshots obtained so far in Cycle14

and Cycle15 these systems frequently exhibit strong gravitational

lensing as well as spectacular examples of violent galaxy interactions.

The proposed observations will provide important constraints on the

cluster mass distributions, the physical nature of galaxy-galaxy and

galaxy-gas interactions in cluster cores, and a set of optically bright,

lensed galaxies for further 8-10m spectroscopy. All of our primary

science goals require only the detection and characterization of

high-surface-brightness features and are thus achievable even at the

reduced sensitivity of WFPC2. Because of their high redshift and thus

compact angular scale our target clusters are less adversely affected by

the smaller field of view of WFPC2 than more nearby systems.

Acknowledging the broad community interest in this sample we waive our

data rights for these observations. Due to a clerical error at STScI our

approved Cycle15 SNAP program was barred from execution for 3 months and

only 6 observations have been performed to date - reinstating this SNAP

at Cycle16 priority is of paramount importance to reach meaningful

statistics.

 

WFPC2 11083

 

The Structure, Formation and Evolution of Galactic Cores and Nuclei

 

A surprising result has emerged from the ACS Virgo Cluster Survey

{ACSVCS}, a program to obtain ACS/WFC gz imaging for a large, unbiased

sample of 100 early-type galaxies in the Virgo Cluster. On subarcsecond

scales {i.e., <0.1"-1"}, the HST brightness profiles vary systematically

from the brightest giants {which have nearly constant surface brightness

cores} to the faintest dwarfs {which have compact stellar nuclei}.

Remarkably, the fraction of galaxy mass contributed by the nuclei in the

faint galaxies is identical to that contributed by supermassive black

holes in the bright galaxies {0.2%}. These findings strongly suggest

that a single mechanism is responsible for both types of Central Massive

Object: most likely internally or externally modulated gas inflows that

feed central black holes or lead to the formation of "nuclear star

clusters". Understanding the history of gas accretion, star formation

and chemical enrichment on subarcsecond scales has thus emerged as the

single most pressing question in the study of nearby galactic nuclei,

either active or quiescent. We propose an ambitious HST program {199

orbits} that constitutes the next, obvious step forward:

high-resolution, ultraviolet {WFPC2/F255W} and infrared {NIC1/F160W}

imaging for the complete ACSVCS sample. By capitalizing on HST's unique

ability to provide high-resolution images with a sharp and stable PSF at

UV and IR wavelengths, we will leverage the existing optical HST data to

obtain the most complete picture currently possible for the history of

star formation and chemical enrichment on these small scales. Equally

important, this program will lead to a significant improvement in the

measured structural parameters and density distributions for the stellar

nuclei and the underlying galaxies, and provide a sensitive measure of

"frosting" by young stars in the galaxy cores. By virtue of its superb

image quality and stable PSF, NICMOS is the sole instrument capable of

the IR observations proposed here. In the case of the WFPC2

observations, high-resolution UV imaging {< 0.1"} is a capability unique

to HST, yet one that could be lost at any time.

 

NIC1/NIC2/NIC3 11060

 

NICMOS Photometric Stability Monitoring

 

This NICMOS calibration proposal carries out photometric monitoring

observations during Cycle 15. The format is the same as the Cycle 14

version of the program {10725}, but a few modifications were made with

respect to the Cycle 12 program 9995 and Cycle 13 program 10381.

Provisions had to be made to adapt to 2-gyro mode {G191B2B was added as

extra target to provide target visibility through most of the year}.

Where before 4 or 7 dithers were made in a filter before we moved to the

next filter, now we observe all filters at one position before moving to

the next dither position. While the previous method was chosen to

minimize the effect of persistence, we now realize that persistence may

be connected to charge trapping and by moving through the filter such

that the count rate increases, we reach equilibrium more quickly between

charge being trapped and released. We have also increased exposure times

where possible to reduce the charge trapping non- linearity effects.

 

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 10812

 

Space Motions for the Draco and Sextans Dwarf Spheroidal Galaxies

 

We will use the powerful astrometric capabilities of HST to measure

proper motions for the Draco and Sextans dwarf spheroidal galaxies that

will yield tangential velocities accurate to about 30 km/s. These two

galaxies are the last inside a galactocentric radius of 200~kpc without

measured proper motions. Knowing their orbits is critical for our

understanding of the low-luminosity satellites of the Milky Way. In

particular they are critical for understanding why Ursa Minor has

survived tidal disruption on its plunging orbit and how Carina formed a

large intermediate-age stellar population despite its small mass.

 

WFPC2 10787

 

Modes of Star Formation and Nuclear Activity in an Early Universe

Laboratory

 

Nearby compact galaxy groups are uniquely suited to exploring the

mechanisms of star formation amid repeated and ongoing gravitational

encounters, conditions similar to those of the high redshift universe.

These dense groups host a variety of modes of star formation, and they

enable fresh insights into the role of gas in galaxy evolution. With

Spitzer mid-IR observations in hand, we have begun to obtain high

quality, multi-wavelength data for a well- defined sample of 12 nearby

{<4500km/s} compact groups covering the full range of evolutionary

stages. Here we propose to obtain sensitive BVI images with the ACS/WFC,

deep enough to reach the turnover of the globular cluster luminosity

function, and WFPC2 U-band and ACS H-alpha images of Spitzer-identified

regions hosting the most recent star formation. In total, we expect to

detect over 1000 young star clusters forming inside and outside

galaxies, more than 4000 old globular clusters in >40 giant galaxies

{including 16 early-type galaxies}, over 20 tidal features,

approximately 15 AGNs, and intragroup gas in most of the 12 groups.

Combining the proposed ACS images with Chandra observations, UV GALEX

observations, ground-based H-alpha imaging, and HI data, we will conduct

a detailed study of stellar nurseries, dust, gas kinematics, and AGN.

 

NIC2 10755

 

Photometric Standard Clusters for Cross-Observatory Calibration

 

The goal of this program is to obtain NICMOS photometry of selected

solar analog stars in selected Galactic clusters that will be used as

on-orbit photometric standard star fields for JWST-NIRCAM. The

availability of such fields at JWST launch will facilitate rapid

photometric calibration of NIRCAM. The NIRCAM team plans to observe the

chosen clusters with Spitzer-IRAC.

 

FLIGHT OPERATIONS SUMMARY:

 

Significant Spacecraft Anomalies: (The following are preliminary reports

of potential non-nominal performance that will be investigated.)

 

HSTARS:

11124 - REAcq(2,3,2) failed to RGA Hold (Gyro Control)

           REAcq(2,3,3) scheduled at 362/12:50:59 failed to RGA Hold due to scan

           step limit exceeded on the primary FGS2. The initial GSAcq at

           362/11:15:06 succeeded. Pre-acquisition OBADs showed (RSS) attitude

           correction values of 1463.38 and 2.31 arseconds. Post-acq OBAD/MAP

           showed 3-axis (RSS) value of 3.66 arcseconds.

 

11125 - REAcq(2,3,2) failed to RGA Hold with QSTOP flags on FGS 2 & 3

           Upon Acquisition Of Signal at 362/22:52:00, REAcq (2,3,3) had failed to

           RGA Hold (Gyro Control). Both FGS-2 & FGS-3 were displaying QSTOP flags.

           Additionally, QF2STOPF & QF3STOPF flags were received. Received 4, 486

           ESB messages "1805" (FHST Moving Target Detected). Pre-acquisition OBAD

           data is unavailable due to scheduled Loss Of Signal. The next scheduled

           engineering data dump is at 363/11:47:00. Post Acquisition OBAD MAP

           displayed the following values: V1 -82.34, V2 -126.16, V3 70.42, RSS

           166.30.

 

           Original GSAcq (2,3,3) scheduled from 362/20:59:54 - 21:07:26 was

           successful.

 

11126 - GSacq(2,3,3) resulted in fine lock backup (2,0,2)

           During LOS, GSacq(2,3,3) scheduled at 364/00:06:09 resulted in fine lock

           backup (2,0,2). The GSacq(2,3,3) resulted in fine lock backup due to

           receiving stop flag QF3STOPF on FGS 3.

 

 

COMPLETED OPS REQUEST: (None)

 

COMPLETED OPS NOTES: (None)

 

                        SCHEDULED      SUCCESSFUL   

FGS GSacq               28                   28               

FGS REacq               13                   11            

OBAD with Maneuver 82                   82               

 

SIGNIFICANT EVENTS: (None)