HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

DAILY REPORT       #4752

PERIOD COVERED: 5am December 8 - 5am December 9, 2008 (DOY

                           343/1000z-344/1000z)

OBSERVATIONS SCHEDULED

FGS 11943

Binaries at the Extremes of the H-R Diagram

We propose to use HST/Fine Guidance Sensor 1r to survey for binaries

among some of the most massive, least massive, and oldest stars in our

part of the Galaxy. FGS allows us to spatially resolve binary systems

that are too faint for ground-based, speckle or optical long baseline

interferometry, and too close to resolve with AO. We propose a

SNAP-style program of single orbit FGS TRANS mode observations of very

massive stars in the cluster NGC 3603, luminous blue variables, nearby

low mass main sequence stars, cool subdwarf stars, and white dwarfs.

These observations will help us to (1) identify systems suitable for

followup studies for mass determination, (2) study the role of binaries

in stellar birth and in advanced evolutionary states, (3) explore the

fundamental properties of stars near the main sequence-brown dwarf

boundary, (4) understand the role of binaries for X-ray bright systems,

(5) find binaries among ancient and nearby subdwarf stars, and (6) help

calibrate the white dwarf mass - radius relation.

FGS/S/C 11945

Asteroseismology of Extrasolar Planet Host Stars

Detections of stellar oscillations, although a very demanding task in

terms of observing time, offers a return of more accurate knowledge

about the structure of stars than can be obtained in any other way. In

particular, detecting the 10-15 highest amplitude modes in solar-like

stars to signal-to-noise of just a few sigma each allows robust

constraints on the stellar density to <1%, and the stellar age to within

5-10% of its main sequence lifetime. Ten day observing runs using the

FGS as a photometer on any of the 5 best transiting planet systems would

enable these asteroseismology returns. From more precisely observed

transit shapes than can be obtained from the ground a completely

independent constraint on stellar density to ~1% can be obtained. The

long observation sets required for asteroseismology also provide an

excellent opportunity of detecting transits from other planets, e.g.

hypothesized inner -orbit Hot Earths, should any exist.

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 11302

WFPC2 CYCLE 16 Standard Darks - Part III

This dark calibration program obtains dark frames every week in order to

provide data for the ongoing calibration of the CCD dark current rate,

and to monitor and characterize the evolution of hot pixels. Over an

extended period these data will also provide a monitor of radiation

damage to the CCDs.

WFPC2 11793

WFPC2 Cycle 16 Internal Monitor

This calibration proposal is the Cycle 15 routine internal monitor for

WFPC2, to be run weekly to monitor the health of the cameras. A variety

of internal exposures are obtained in order to provide a monitor of the

integrity of the CCD camera electronics in both bays (both gain 7 and

gain 15 -- to test stability of gains and bias levels), a test for

quantum efficiency in the CCDs, and a monitor for possible buildup of

contaminants on the CCD windows. These also provide raw data for

generating annual super-bias reference files for the calibration

pipeline.

WFPC2 11962

A New Supernova in the Antennae; Narrowing in on the Hubble Constant and

Dark Energy

A measurement of the Hubble constant to a precision of a few percent

would be a powerful aid to the investigation of the nature of dark

energy and a potent "end-to-end" test of the present cosmological model.

In Cycle 15 we constructed a new, streamlined distance ladder utilizing

high-quality type Ia supernova data and observations of Cepheids with

HST in the near-IR to minimize the dominant sources of systematic

uncertainty in past measurements of the Hubble constant and reduce its

total uncertainty to a little under 5%. Here we propose to exploit this

new route with a rare opportunity to begin reducing the remaining

uncertainty. SN 2007sr in the Antennae (NGC 4038/9) is the rare SN Ia

which is suitable for increasing the precision of small calibration

sample of SNe Ia. Even rarer is that it is close enough that it's

Cepheids are within range of observing with WFPC2 (and NICMOS, should it

return to life). But we need to act fast as the window of long

visibility and fixed orient runs from mid-early December 2008 to early

March 2009. We request 34 orbits with WFPC2 to find the Cepheids in the

SN host. We also request 16 orbits to observe the Cepheids we find with

Camera 2, F160W if NICMOS becomes available by April 2009 . (If NICMOS

does not return we would forgo these observations and ask the TTRB to

let us make them with our own WFC3-IR allocation, though we much prefer

the smaller pixel size of NIC2).

FLIGHT OPERATIONS SUMMARY:

Significant Spacecraft Anomalies: (The following are preliminary reports

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

HSTARS:

11603 - GSAcq (1,3,1) failed to RGA Hold (Gyro Control) @ 344/06:03.

           Observations affected: Proposal 11945 Guide Star Acq Tests in

                                           343SMS(FGS-1R K16) Reduction

COMPLETED OPS REQUEST:

18368-0 - Lower FGS1 K16 for Proposal 11945 guide star testing

COMPLETED OPS NOTES: (None)

SIGNIFICANT EVENTS:

FLASH Report: FGS-1R K16 K-factor changed.

The FGS-1R K16 K-factor was successfully changed by Ops Request #18368

at 344/00:55. The new value of 4982 was verified by TMDIAGs. The value

will be reset to the original value of 12,335 by SMS commanding at

2008.344/09:16:32