HUBBLE SPACE TELESCOPE - Continuing to Collect World Class Science

DAILY REPORT #5178

PERIOD COVERED: 5am September 9 - 5am September 10, 2010 (DOY 252/09:00z-253/09:00z)

FLIGHT OPERATIONS SUMMARY:

Significant Spacecraft Anomalies: (The following are preliminary reports

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

HSTARS:

12390 - SIC&DH Safed (CU/SDF lockup) @ 252 /22:39:21z

12392 - WFC3 Suspends at 253/04:24:35

12393 - SIC&DH-2 Bus B Current Monitor Failure @ 253/03:38:50z

COMPLETED OPS REQUEST:

18901-1 - CU/SDF Lock-up Recovery, Part B @ 253/04:19:40z

18903-0 - CU/SDF Lock-up Recovery, Part A @ 253/00:20:30z

18904-1 - Power off COS FUV @ 253/07:54:54z

18905-0 - Modify NSSC-1 ED Limit for M2BUSCUB @ 253/08:01:49z

COMPLETED OPS NOTES: None

                     SCHEDULED SUCCESSFUL

FGS GSAcq               6            6                 

FGS REAcq               9             9         

OBAD with Maneuver 5             5 

SIGNIFICANT EVENTS:

HST experienced an SIC&DH CU/SDF lock-up at 252/22:39z.

After verification of the signature the CU/SDF recovery began.

OBSERVATIONS SCHEDULED:

ACS/WFC 12292

SWELLS: Doubling the Number of Disk-dominated Edge-on Spiral Lens

Galaxies

The formation of realistic disk galaxies within the LCDM cosmology is

still largely an unsolved problem. Theory is now beginning to make

predictions for how dark matter halos respond to galaxy formation, and

for the properties of disk galaxies. Measuring the density profiles of

dark matter halos on galaxy scales is therefore a strong test for the

standard paradigm of galaxy formation, offering great potential for

discovery. However, the degeneracy between the stellar and dark matter

contributions to galaxy rotation curves remains a major obstacle. Strong

gravitational lensing, when combined with spatially resolved kinematics

and stellar population models, can solve this long-standing problem.

Unfortunately, this joint methodology could not be exploited until

recently due to the paucity of known edge-on spiral lenses. We have

developed and demonstrated an efficient technique to find exactly these

systems. During supplemental cycle-16 we discovered five new spiral lens

galaxies, suitable for rotation curve measurements. We propose

multi-color HST imaging of 16 candidates and 2 partially-imaged

confirmed systems, to measure a sample of eight new edge-on spiral

lenses. This program will at least double the number of known

disk-dominated systems. This is crucial for constraining the relative

contribution of the disk, bulge and dark halo to the total density

profile.

STIS/CCD/MA 11576

Physical Parameters of the Upper Atmosphere of the Extrasolar Planet

HD209458b

One of the most studied extrasolar planet, HD209458b, has revealed both

its lower and upper atmosphere thanks to HST and Spitzer observatories.

Through transmission spectroscopy technique, several atmospheric species

were detected: NaI, HI, OI and CII. Using STIS archived transit

absorption spectrum from 3000 to 8000 Angstrom, we obtained detailed

constraints on the vertical profile of temperature, pressure and

abundances (Sing et al 2008a, 2008b, Lecavelier et al. 2008b).

By observing in the NUV, from 2300 to 3100 Angstrom, we expect to obtain

new constraints on the physical conditions and the chemical composition

of the upper atmosphere: temperature/pressure profile up to very high in

the atmosphere, abundance and condensation altitudes of new species, and

new insight in the atmospheric escape and ionization state at the upper

levels. The observation of four HD209458b transits with a single E230M

setting will give access to many NUV atomic lines addressing these

issues. The proposed observations will probe, for the first time, in

details the atmosphere of a hot Jupiter, thus bench marking follow up

studies.

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/CCD/MA 12179

The Stellar Winds of Evolved, Braked O-Type Magnetic Oblique Rotators

Magnetic fields have recently been discovered on several massive stars,

but their origin and influence on the evolution of these stars are

poorly understood. Two of these objects, HD 191612 and HD 108, are of

particular interest. Very recent spectropolarimetric observations have

shown that they are most likely magnetic oblique rotators, like the

young O star Theta1 Ori C, whose 15d periodically variable field was

found somewhat earlier. However, the two new objects are much slower

rotators, unusually so for O stars, with periods of 538d and 50-60yrs,

respectively, and there are other indications that they are older. They

provide an opportunity to study the efficiency of wind braking of

magnetic O stars through angular momentum loss. We shall perform STIS

high-resolution UV spectroscopy of HD 191612 and HD 108 (phase resolved

for the former) to derive more complete estimates of fundamental

quantities than available from optical data alone. We shall measure the

mass-loss rates from the UV wind profiles, which will constrain the

extreme wind confinement of these stars and establish whether the large

H-alpha emission variations are wind-related or geometrical. We shall

also derive more accurate ages and stellar surface properties. In turn,

these results will support a more definitive discussion of the angular

momentum evolution versus the ages of HD 191612 and HD 108, and of the

comparison with the younger and faster Theta1 Ori C.

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).

S/C 11639

Catching Accreting WDs Moving into Their Instability Strip(s)

Our past HST studies of the temperatures of 9 accreting, pulsating white

dwarfs in cataclysmic variables show that 3 are in the normal

instability strip for single white dwarfs, but the other 6 are much

hotter (15, 000-16, 500K). This dual strip has been proposed to be due

to mass differences in the white dwarfs related to evolutionary history

and driven by the ionization of different elements in their respective

driving regions. In 2007, GW Lib (the brightest and best studied of the

6 hot accreting pulsators) and V455 And (the brightest and best studied

of the 3 cool accreting pulsators) underwent rare large amplitude dwarf

nova outbursts (known to heat the white dwarf) and their pulsations

disappeared. We propose COS observations to: a) take advantage of the

unprecedented opportunity to view the change in pulsation modes due to

cooling of the white dwarf envelope and b) determine the masses of the

white dwarfs to test the dual strip theory. In addition, a nova that had

its outburst 22 yrs ago has begun non-radial pulsations as it returns to

quiescence. We will use COS to determine its temperature in relation to

the instability strip for the pulsating white dwarfs in dwarf novae.

WFC3/UVIS 11675

Stellar Forensics: A Post-Explosion View of the Progenitors of

Core-Collapse Supernovae

Recent studies have used high spatial resolution HST observations of SN

sites to identify the progenitors of core-collapse SNe on pre-explosion

images. These studies have set constraints about the nature of massive

stars and their evolution just prior to their explosion as SNe. Now, at

late-times when the SNe have faded sufficiently, it is possible to

return to the sites of these core-collapse SNe to search for clues about

the nature of their progenitors. We request time to conduct deep,

late-time, high-resolution imaging with ACS/HRC of the sites of six

core-collapse SNe. In this program we aim to: 1) confirm our

identifications, that were made with HST pre-explosion images, of the

red supergiant progenitors of four Type IIP SNe (1999ev, 2003gd, 2004A

and 2005cs), by observing if the objects identified as the progenitors

are now missing; 2) place precise constraints on the progenitor of the

Type Ic SN 2007gr by studying its host cluster; and 3) confirm our

identification of an LBV-like outburst of an unstable WR star as

belonging to the progenitor of a Type Ib-n core-collapse SN (2006jc),

using broad and narrow-band imaging to search for emission line stars in

its locality. The deep imaging will also allow to probe the stellar

populations in the immediate vicinities of these SNe, that were

previously obscured by the progenitors and the bright SNe. HST provides

the unique combination of high-resolution optical imaging at very faint

magnitudes that will facilitate this study.

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).