HUBBLE SPACE TELESCOPE - Continuing to Collect World Class Science

DAILY REPORT #5167

PERIOD COVERED: 5am August 24 - 5am August 25, 2010 (DOY 236/09:00z-237/09:00z)

FLIGHT OPERATIONS SUMMARY:

Significant Spacecraft Anomalies: (The following are preliminary reports

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

HSTARS:

For DOY 221:

12362 - GSAcq(2,1,1) at 221/23:59:30z required two attempts to achieve CT-DV on FGS2.

           Observations possibly affected:  STIS 12 Proposal ID#11568

COMPLETED OPS REQUEST: (None)

COMPLETED OPS NOTES: (None)

                       SCHEDULED      SUCCESSFUL

FGS GSAcq               04                 04               

FGS REAcq               11                 11                

OBAD with Maneuver 03                 03                 

SIGNIFICANT EVENTS: (None)

OBSERVATIONS SCHEDULED:

STIS/CCD 11845

CCD Dark Monitor Part 2

Monitor the darks for the STIS CCD.

STIS/CCD 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/MA1/MA2 11857

STIS Cycle 17 MAMA Dark Monitor

This proposal monitors the behavior of the dark current in each of the

MAMA detectors.

The basic monitor takes two 1380s ACCUM darks each week with each

detector. However, starting Oct 5, pairs are only included for weeks

that the LRP has external MAMA observations planned. The weekly pairs of

exposures for each detector are linked so that they are taken at

opposite ends of the same SAA free interval. This pairing of exposures

will make it easier to separate long and short term temporal variability

from temperature dependent changes.

For both detectors, additional blocks of exposures are taken once every

six months. These are groups of five 1314s FUV-MAMA Time-Tag darks or

five 3x315s NUV ACCUM darks distributed over a single SAA-free interval.

This will give more information on the brightness of the FUV MAMA dark

current as a function of the amount of time that the HV has been on, and

for the NUV MAMA will give a better measure of the short term

temperature dependence.

WFC3/IR/ACS/WFC 12331

Massive Star CSI: Has The Progenitor of SN2008S Vanished?

SN2008S in NGC6946 is the prototype of a new class of optical

transients. Its luminosity was low for a Type II supernova, and the

progenitor star was identified as a completely dust obscured log

(L/Lsun)=4.5, T=440K massive star (~10 Msun) in archival Spitzer data.

It is uncertain whether this is a new class of low-luminosity supernova

(e.g. an electron capture supernova) or a new class of massive star

outburst. The transient has now faded to the point where the source is

again invisible in the optical. Near-IR detections are consistent with a

somewhat hotter source, T~1200K, somewhat brighter than the progenitor

and still fading at ~3 mag/year. Using two epochs of IRAC observations

to constrain the mid-IR emission, and two epochs of HST H-band/J-band

observations to constrain emission from cool stars, we will solve this

mystery by either identifying and characterizing the surviving

progenitor or ruling out its survival.

WFC3/UV 11638

Illuminating the HI Structure of a Proto-cluster Region at z=2.84

We propose very deep intermediate-band Lyman alpha imaging in the field

of a newly-discovered proto-cluster region surrounding the extremely

luminous QSO HS1549+19 at z=2.844. The large structure, initially

discovered in a spectroscopic survey of galaxies in fields surrounding

the brightest QSOs at z=2.5-2.8, represents an ideal laboratory for

studying the response of the intergalactic medium to a source of

ionizing photons that exceeds the UV background by factors >1000. Within

a single pointing of WFC3-UVIS there are already more than 45 known

Lyman alpha emitters, most of which are already spectroscopically

confirmed, and at least 3 of which are giant ``Lyman alpha blobs''. Many

of the objects have properties similar to those expected from the

process of fluorescence, in which Lyman alpha emission is induced by the

UV radiation field of the QSO in any HI gas that dense enough to remain

partially self-shielded. Fortuitously, the F467M filter (Stromgren "b")

in WFC3-UVIS is a perfect match to Lyman alpha at z=2.844. In

combination with an equally deep broad-band continuum image, the

observations will allow the construction of a Lyman alpha map tracing

dense gas throughout the inner parts of a proto-cluster region at

sub-kpc resolution. The ability to measure the spatial sub-structure and

surface brightness distribution of Lya emission, relative to known

protocluster galaxies and AGN, will illuminate the “cosmic web'' in a

dense region caught in a violent stage of formation.

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).