HUBBLE SPACE TELESCOPE - Continuing to Collect World Class Science

DAILY REPORT #5130

PERIOD COVERED: 5am July 1 - 5am July 2, 2010 (DOY 182/09:00z-183/09:00z)

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                 4                4                

FGS REAcq                12               12               

OBAD with Maneuver   4                4                

SIGNIFICANT EVENTS: (None)

OBSERVATIONS SCHEDULED:

ACS/WFC3 11586

Exceptional Galactic Halo Globular Clusters and the Second Parameter

We propose to obtain deep ACS-WFC images of six globular clusters (five

of which have no previous HST photometry) that reside in the Galactic

halo, where the second parameter effect is most pronounced. These

globular clusters are among the least studied in the Galaxy and yet,

from the perspective of the second parameter phenomenon, the most

intriguing.

With the best available CMDs only reaching the vicinity of the main

sequence turn off at present, the unique sensitivity and resolution of

ACS-WFC will yield ages of unprecedented precision for these clusters.

These data will provide us with new insight into the stellar populations

present in the outer Galactic halo and the nature of the second

parameter. The second parameter plays a critical role in our

understanding of the formation and evolution of the Galaxy and the

proposed observations will shed new light on this problem and these

exceptional clusters.

COS/NUV/FUV 11659

Probing the Interior of SN1006

The remnant of SN 1006 is unique among all supernova remnants in having

3 identified background UV sources that can be used to probe cold,

otherwise unseen ejecta within the remnant shell. We propose

high-resolution spectra from COS to obtain spectra of all three of

these. The brightest of these, the Schweizer-Middleditch star (the only

one with extensive previous high-quality UV spectra) shows Si II

absorption with an extremely unusual asymmetric profile with a sharp

edge on the red end, indicating the velocity of material just entering

the reverse shock. Our new spectrum can be compared with STIS

observations from 1999 to measure definitively the velocity change as

the reverse shock eats its way into ever-more- slowly-expanding ejecta.

One may well ask, however, if this profile is truly representative, and

we seek to answer that with a spectrum of a background quasar at a

similar distance of the SM star from the projected center, but in a

different direction. And by investigating the detailed structure of

these two sources and a second quasar, we can probe small-scale

structure in the ejecta. No object other than SN1006 offers a similar

opportunity to probe the distribution of ejecta within the remnant of a

Type Ia supernova.

S/C 12046

COS FUV DCE Memory Dump

Whenever the FUV detector high voltage is on, count rate and current

draw information is collected, monitored, and saved to DCE memory. Every

10 msec the detector samples the currents from the HV power supplies

(HVIA, HVIB) and the AUX power supply (AUXI). The last 1000 samples are

saved in memory, along with a histogram of the number of occurrences of

each current value.

In the case of a HV transient (known as a "crackle" on FUSE), where one

of these currents exceeds a preset threshold for a persistence time, the

HV will shut down, and the DCE memory will be dumped and examined as

part of the recovery procedure. However, if the current exceeds the

threshold for less than the persistence time (a "mini-crackle" in FUSE

parlance), there is no way to know without dumping DCE memory. By

dumping and examining the histograms regularly, we will be able to

monitor any changes in the rate of "mini-crackles" and thus learn

something about the state of the detector.

STIS/CC 11845

CCD Dark Monitor Part 2

Monitor the darks for the STIS CCD.

STIS/CC 11847

CCD Bias Monitor-Part 2

Monitor the bias in the 1x1, 1x2, 2x1, and 2x2 bin settings at gain=1,

and 1x1 at gain = 4, to build up high-S/N superbiases and track the

evolution of hot columns.

STIS/CCD/MA1/MA2 11839

The Cycles of Alpha Centauri

This is the HST part of a joint Chandra/HST observing program. The

objective of the HST part is to obtain new UV spectra of both components

of the Alpha Centauri binary: the primary ("Alpha Cen A") is a near twin

of the Sun, while the companion ("B") is an early K dwarf, slightly less

massive, smaller and less luminous than the Sun. The orbital period is

80 yr, and the two stars currently are separated by about 8". The Alpha

Cen system has been the subject of long term coronal X-ray monitoring by

four successive generations of space observatories, and extensive UV

measurements were obtained periodically during the IUE era, from the

late 1970's to late 1990's. The present program will obtain new STIS

echelle spectra of both stars, which each were observed in selected

wavelength windows by GHRS in the mid-1990's, and Alpha Cen A later by

STIS in an extensive high-res program in 1999, although B unfortunately

never was recorded by STIS.

WFC3/IR 11631

Binary Brown Dwarfs and the L/T Transition

Brown dwarfs traverse spectral types M, L and T as their atmospheric

structure evolves and they cool into oblivion. This SNAPSHOT program

will obtain WFC3-IR images of 45 nearby late-L and early-T dwarfs to

investigate the nature of the L/T transition. Recent analyses have

suggested that a substantial proportion of late-L and early-T dwarfs are

binaries, comprised of an L dwarf primary and T dwarf secondary. WFC3-IR

observations will let us quantify this suggestion by expanding coverage

to a much larger sample, and permitting comparison of the L/T binary

fraction against ‘normal’ ultracool dwarfs. Only eight L/T binaries are

currently known, including several that are poorly resolved: we

anticipate at least doubling the number of resolved systems. The

photometric characteristics of additional resolved systems will be

crucial to constraining theoretical models of these late-type ultracool

dwarfs. Finally, our data will also be eminently suited to searching for

extremely low luminosity companions, potentially even reaching the Y

dwarf regime.

WFC3/IR 11648

WFC3 Spectroscopy of an X-ray Luminous Galaxy Cluster at z>2

We propose to obtain deep WFC3+G141 grism observations to

spectroscopically confirm a remarkable z>2 cluster of galaxy candidate.

Over a 1000 arcmin^2 field imaged with Spitzer's IRAC we have discovered

a compact (<30ÕÕ diameter) concentration of extremely red galaxies with

a factor of >40 overdensity over the adjacent field. Among these

galaxies for which we can derive meaningful photometric redshifts, 17

are consistent with zphot=2-2.5, making it very likely that the

concentration is a real cluster at such high redshift. This is further

supported by a 3.5 sigma detection of extended X-Ray emission on

XMM-Newton data, by a likely color magnitude sequence of red galaxies,

and by the presence of a giant galaxy consistent with a BCG at the

cluster redshift. The general faintness of the red galaxies in all

optical bands and their high redshifts prevent confirmation of this

cluster with ordinary optical spectroscopy. The WFC3 camera with G141

grism provides the only way to confirm this record high-z cluster and

measure its redshift from spectral breaks typical of old stellar

populations. Our deep integrations will reveal redshifts for at least 19

ultra-red galaxies in the area and of a similar number of bluer galaxies

at the cluster redshift. Knowledge of the cluster redshift based on the

HST spectra will allow us to reach important scientific aims: find the

most distant Xray emitting evolved galaxy cluster, determine membership

of the other galaxies from photometric SED analysis, study their stellar

population properties, characterize the color-magnitude relation with

constraints on the formation redshift. The proposed observations will

establish a first z>2 benchmark for cluster field comparisons of galaxy

formation at this highest redshift and will firmly establish the

progenitors of local rich Abell clusters.

WFC3/IR 11915

IR Internal Flat Fields

This program is the same as 11433 (SMOV) and depends on the completion

of the IR initial alignment (Program 11425). This version contains three

instances of 37 internal orbits: to be scheduled early, middle, and near

the end of Cycle 17, in order to use the entire 110-orbit allocation.

In this test, we will study the stability and structure of the IR

channel flat field images through all filter elements in the WFC3-IR

channel. Flats will be monitored, i.e. to capture any temporal trends in

the flat fields and delta flats produced. High signal observations will

provide a map of the pixel-to-pixel flat field structure, as well as

identify the positions of any dust particles.

WFC3/IR/S/C 11929

IR Dark Current Monitor

Analyses of ground test data showed that dark current signals are more

reliably removed from science data using darks taken with the same

exposure sequences as the science data, than with a single dark current

image scaled by desired exposure time. Therefore, dark current images

must be collected using all sample sequences that will be used in

science observations. These observations will be used to monitor changes

in the dark current of the WFC3-IR channel on a day-to-day basis, and to

build calibration dark current ramps for each of the sample sequences to

be used by Gos in Cycle 17. For each sample sequence/array size

combination, a median ramp will be created and delivered to the

calibration database system (CDBS).

WFC3/UVIS 11905

WFC3 UVIS CCD Daily Monitor

The behavior of the WFC3 UVIS CCD will be monitored daily with a set of

full-frame, four-amp bias and dark frames. A smaller set of 2Kx4K

subarray biases are acquired at less frequent intervals throughout the

cycle to support subarray science observations. The internals from this

proposal, along with those from the anneal procedure (Proposal 11909),

will be used to generate the necessary superbias and superdark reference

files for the calibration pipeline (CDBS).

WFC3/UVIS 11908

Cycle 17: UVIS Bowtie Monitor

Ground testing revealed an intermittent hysteresis type effect in the

UVIS detector (both CCDs) at the level of ~1%, lasting hours to days.

Initially found via an unexpected bowtie-shaped feature in flatfield

ratios, subsequent lab tests on similar e2v devices have since shown

that it is also present as simply an overall offset across the entire

CCD, i.e., a QE offset without any discernable pattern. These lab tests

have further revealed that overexposing the detector to count levels

several times full well fills the traps and effectively neutralizes the

bowtie. Each visit in this proposal acquires a set of three 3x3 binned

internal flatfields: the first unsaturated image will be used to detect

any bowtie, the second, highly exposed image will neutralize the bowtie

if it is present, and the final image will allow for verification that

the bowtie is gone.

-Lynn               

NASA office: 301-286-2876

_______________________________________________________
Lynn F. Bassford
Hubble Space Telescope
CHAMP Mission Operations Manager
CHAMP Flight Operations Team Manager
Lockheed Martin Mission Services (LMMS)

"...Hubble is the most significant science instrument of all time in terms of its productivity..."     Scott Altman @12:45pm 5/21/9 STS-125 Senate Subcommittee Hearing