HUBBLE SPACE TELESCOPE - Continuing to Collect World Class Science



DAILY REPORT #4922



PERIOD COVERED: 5am September 1 - 5am September 2, 2009 (DOY 244/09:00z-245/09:00z)



OBSERVATIONS SCHEDULED



ACS/WFC3 11882



CCD Hot Pixel Annealing



All the data for this program is acquired using internal targets (lamps)

only, so all of the exposures should be taken during Earth occultation

time (but not during SAA passages). This program emulates the ACS

pre-flight ground calibration and post-launch SMOV testing (program

8948), so that results from each epoch can be directly compared.

Extended Pixel Edge Response (EPER) and First Pixel Response (FPR) data

will be obtained over a range of signal levels for the Wide Field

Channel (WFC). The High Resolution Channel (HRC) visits have been

removed since it could not be repaired during SM4.



COS/FUV 11488



Internal FUV Wavelength Verification



This program will be executed after the uplink of the OSM1 position

updates derived from the determination of the wavelength-scale zero

points and desired spectral ranges for each grating in Activity COS29

(Program 11487 - COS FUV Internal/External Wavelength Scales). This

program will verify that the operational spectral ranges for each

grating, central wavelength, and FP-POS are those desired. Subsequent to

a successful verification, COS FUV ERO observations that require

accurate wavelength scales (if any) and FUV science can be enabled. An

internal wavelength calibration spectrum using the default PtNe lamp

(lamp 1) with each FUV grating at each central wavelength setting and

each FP-POS position will be obtained for the verification. Additional

exposures and waits between certain exposures will be required to avoid

- and to evaluate - mechanism drifts.



COS/FUV 11491



COS FUV External Flat Fields



Obtain external spectra of flat field targets at different positions

along the cross- dispersion direction of the FUV detector (and at a

variety of FP-POS positions) in order to obtain an FUV flat field. The

choices of gratings and positions of the target in the aperture have

been made in order to maximize the coverage on the detector in the

cross-dispersion direction and cover the entire region where science

spectra will fall.



COS/FUV 11897



FUV Spectroscopic Sensitivity Monitoring



The purpose of this proposal is to monitor sensitivity in each FUV

grating mode to detect any changes due to contamination or other causes.



COS/NUV 11896



NUV Spectroscopic Sensitivity Monitoring



The purpose of this proposal is to monitor sensitivity of each NUV

grating mode to detect any changes due to contamination or other causes.



FGS 11706



The Parallax of the Planet Host Star XO-3



We will use HST+FGS to measure the parallax of the transiting planet

host star XO 3. The resulting accurate distance measurement will provide

the most accurate radius determination to date for this massive

extrasolar planet (XO-3B), allowing us to critically test current giant

extrasolar planet structure models. These observations will also

constrain the amount of heating that may be produced inside XO-3B by

tides raised on the planet as it moves through its 3.2 d-eccentric (e ~

0.22) orbit.



FGS 11788



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.



FGS 11789



An Astrometric Calibration of Population II Distance Indicators



In 2002, HST produced a highly precise parallax for RR Lyrae. That

measurement resulted in an absolute magnitude, M(V)= 0.61+/-0.11, a

useful result, judged by the over ten refereed citations each year

since. It is, however, unsatisfactory to have the direct,

parallax-based, distance scale of Population II variables based on a

single star. We propose, therefore, to obtain the parallaxes of four

additional RR Lyrae stars and two Population II Cepheids, or W Vir

stars. The Population II Cepheids lie with the RR Lyrae stars on a

common K-band Period-Luminosity relation. Using these parallaxes to

inform that relationship, we anticipate a zero-point error of 0.04

magnitude. This result should greatly strengthen confidence in the

Population II distance scale and increase our understanding of RR Lyrae

star and Pop. II Cepheid astrophysics.



STIS/CCD 11843



STIS CCD Performance Monitor



This activity measures the baseline performance and commandability of

the CCD subsystem. Only primary amplifier D is used. Bias and Flatfield

exposures are taken in order to measure bias level, read noise, CTE, and

gain. Numerous bias frames are taken to permit construction of

"superbias" frames in which the effects of read noise have been rendered

negligible. Full frame and binned observations are made, with binning

factors of 2 x 1, 1 x 2, 2 x 2. Bias frames are taken in subarray

readouts to check the bias level for ACQ and ACQ/PEAK observations. All

exposures are internals.



STIS/CCD 11844



CCD Dark Monitor Part 1



Monitor the darks for the STIS CCD.



STIS/CCD 11846



CCD Bias Monitor-Part 1



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 11850



CCD Sparse Field CTE Internal



CTE measurements are made using the "internal sparse field test", along

the parallel axis. The "Pos=" optional parameter, introduced during

Cycle 11, is used to provide off- center MSM positionings of some slits.

All exposures are internals.



STIS/CCD 11852



STIS CCD Spectroscopic Flats C17



Obtain pixel-to-pixel lamp flat fields for the STIS CCD in spectroscopic

mode.



STIS20 11402



STIS-20 NUV MAMA Dark Monitor



The STIS NUV-MAMA dark current is dominated by a phosphorescent glow

from the detector window. Meta-stable states in this window are

populated by cosmic ray impacts, which, days later, can be thermally

excited to an unstable state from which they decay, emitting a UV

photon. The equilibrium population of these meta-stable states is larger

at lower temperatures; so warming up the detector from its cold safing

will lead to a large, but temporary, increase in the dark current.



To monitor the decay of this glow, and to determine the equilibrium dark

current for Cycle 17, four 1380s NUV-MAMA ACCUM mode darks should be

taken each week during the SMOV period. Once the observed dark current

has reached an approximate equilibrium with the mean detector

temperature, the frequency of this monitor can be reduced to one pair of

darks per week.



WFC3/ACS/IR 11563



Galaxies at z~7-10 in the Reionization Epoch: Luminosity Functions to

<0.2L* from Deep IR Imaging of the HUDF and HUDF05 Fields



The first generations of galaxies were assembled around redshifts

z~7-10+, just 500-800 Myr after recombination, in the heart of the

reionization of the universe. We know very little about galaxies in this

period. Despite great effort with HST and other telescopes, less than

~15 galaxies have been reliably detected so far at z>7, contrasting with

the ~1000 galaxies detected to date at z~6, just 200-400 Myr later, near

the end of the reionization epoch. WFC3 IR can dramatically change this

situation, enabling derivation of the galaxy luminosity function and its

shape at z~7-8 to well below L*, measurement of the UV luminosity

density at z~7-8 and z~8-9, and estimates of the contribution of

galaxies to reionization at these epochs, as well as characterization of

their properties (sizes, structure, colors). A quantitative leap in our

understanding of early galaxies, and the timescales of their buildup,

requires a total sample of ~100 galaxies at z~7-8 to ~29 AB mag. We can

achieve this with 192 WFC3 IR orbits on three disjoint fields

(minimizing cosmic variance): the HUDF and the two nearby deep fields of

the HUDF05. Our program uses three WFC3 IR filters, and leverages over

600 orbits of existing ACS data, to identify, with low contamination, a

large sample of over 100 objects at z~7-8, a very useful sample of ~23

at z~8-9, and limits at z~10. By careful placement of the WFC3 IR and

parallel ACS pointings, we also enhance the optical ACS imaging on the

HUDF and a HUDF05 field. We stress (1) the need to go deep, which is

paramount to define L*, the shape, and the slope alpha of the luminosity

function (LF) at these high redshifts; and (2) the far superior

performance of our strategy, compared with the use of strong lensing

clusters, in detecting significant samples of faint z~7-8 galaxies to

derive their luminosity function and UV ionizing flux. Our recent z~7.4

NICMOS results show that wide-area IR surveys, even of GOODS-like depth,

simply do not reach faint enough at z~7-9 to meet the LF and UV flux

objectives. In the spirit of the HDF and the HUDF, we will waive any

proprietary period, and will also deliver the reduced data to STScI. The

proposed data will provide a Legacy resource of great value for a wide

range of archival science investigations of galaxies at redshifts z~2-9.

The data are likely to remain the deepest IR/optical images until JWST

is launched, and will provide sources for spectroscopic followup by

JWST, ALMA and EVLA.



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 11714



Snapshot Survey for Planetary Nebulae in Local Group Globular Clusters



Planetary nebulae (PNe) in globular clusters (GCs) raise a number of

interesting issues related to stellar and galactic evolution. The number

of PNe known in Milky Way GCs, four, is surprisingly low if one assumes

that all stars pass through a PN stage. However, it is likely that the

remnants of stars now evolving in galactic GCs leave the AGB so slowly

that any ejected nebula dissipates long before the star becomes hot

enough to ionize it. Thus there should not be ANY Pne in Milky Way

GCs--but there are four! It has been suggested that these Pne are the

result of mergers of binary stars within GCs, i.e., that they are

descendants of blue stragglers. The frequency of occurrence of Pne in

external galaxies poses more questions, because it shows a range of

almost an order of magnitude.



I propose a Snapshot survey aimed at discovering Pne in the GC systems

of Local Group galaxies outside the Milky Way. These clusters, some of

which may be much younger than their counterparts in our galaxy, might

contain many more Pne than those of our own galaxy. I will use the

standard technique of emission-line and continuum imaging, which easily

discloses Pne. This proposal continues a WFPC2 program started in Cycle

16, but with the more powerful WFC3. As a by-product, the survey will

also produce color-magnitude diagrams for numerous clusters for the

first time, reaching down to the horizontal branch.



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 (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.



FLIGHT OPERATIONS SUMMARY:



Significant Spacecraft Anomalies: (The following are preliminary reports

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



HSTARS:

12001 - GSAcq 1,2,1 scheduled from 244/21:59:48 - 244/22:06:30, failed due to

Search Radius Limit Exceeded on FGS-1.



Observations affected: COS 40 & 41 Proposal ID# 11897,

WFC3 22 proposal ID# 11908.



COMPLETED OPS REQUEST: (None)



COMPLETED OPS NOTES: (None)



SCHEDULED SUCCESSFUL

FGS GSAcq 8 7

FGS REAcq 5 5

OBAD with Maneuver 8 8



SIGNIFICANT EVENTS: (None)


David Cottle

UBB Owner & Administrator