HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science



DAILY REPORT #4897



PERIOD COVERED: 5am July 28 - 5am July 29, 2009 (DOY 209/09:00z-210/09:00z)



OBSERVATIONS SCHEDULED



ACS 11465



ACS CCD Monitoring and Calibration for WFC3



This program is a smaller version of our routine CCD monitoring program,

designed to run throughout SMOV, after which our regular Cycle 17 CAL

proposal will begin. This program obtains the bias and dark frames

needed to generate reference files for calibrating science data, and

allows us to monitor detector noise and the growth of hot pixels.



COS 11474



COS NUV Internal/External Wavelength Scales



Observe external radial velocity standard targets (preferably, though

not required, in CVZ) in TIME-TAG (FLASH=YES) mode with as many grating

and central wavelength combinations as feasible. The purpose is to

obtain zero-point offsets for the wavelength scale (internal wavecal

lamp scale to external standard wavelength scale) for all central

wavelengths. Following this determination, adjustments of the nominal

science target spectral range for each grating and central wavelength

combination will be made via SMS patchable constant for nominal OSM2

positions corresponding to each central wavelength. Subsequent to this

modification of the wavelength scale (and its verification in COS 15 -

program 11475), NUV science-related operations and wavelength-scale

dependent EROs can commence.



COS 11478



COS NUV Flat Fields



Acquire long NUV flat field exposures using the internal deuterium

calibration lamp with the G185M grating. Use central wavelengths of 1835

angstroms, 1850 angstroms, and 1864 angstroms. Based on data taken

during thermal vacuum testing in 2003 (Test 1750), a total of 65,000

seconds of data should be sufficient to obtain ~7.5x10^7 total counts in

the science region of the detector (> 200 counts per pixel, or 1800

counts per 3 x 3 pixel resolution element).



This is SMOV4 Activity COS-18.



STIS07 11404



CCD Dark and Bias Monitor for SMOV4/Cycle 17 Activity STIS-07



Monitor the darks for the STIS CCD. 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.



STIS21 11391



STIS-21 FUV-MAMA Optical Format Verification



For each FUV-MAMA spectral optical element in the MSM (G140L, G140M,

E140M, E140H), a LINE lamp spectrum will be taken to match selected

observations that were done as part of the cycle 11 STIS/CAL program

9618. These observations will be done at one CENWAVE value of each

grating, will verify the optical paths and MSM positioning used for each

of these modes, and will also allow a check of the spectral resolution.

The normal monthly MSM offsetting will be turned off and the zero-offset

MSM positions used for these observations.



WFC3 11808



WFC3 UVIS Bowtie Monitor



The UVIS detector was observed during ground testing to occasionally

exhibit flat field and dark variations with a bowtie pattern. These

variations are most significant as ~1% flat field (gain) variations

across the field of view. It is believed that this represents a state or

condition into which the detector can transition for reasons and under

circumstances which are not currently understood. It is also very

unlikely that most science observations will determine the state (bowtie

or no-bowtie) of the detector. Ground test data indicates that this

state is long lived (many hours to ~one day). Hysteresis or memory of

past light exposure is also associated with this state.



Recent evidence suggests that exposing the detector to ~200k to 500k

electrons may quench this state. This proposal obtains an internal flat

field sequence of three exposures: one at 10x full well with two at 0.5x

full well immediately before and after. Each exposure is 3x3 binned to

reduce the data volume required.



These visits should be scheduled 2x per day until further direction is

provided.



WFC3/UVI 11565



A Search for Astrometric Companions to Very Low-Mass, Population II

Stars



We propose to carry out a SNAPshot search for astrometric companions in

a subsample of very low-mass, halo subdwarfs identified within 120

parsecs of the Sun. These ultra- cool M subdwarfs are local

representatives of the lowest-mass H-burning objects from the Galactic

Population II. The expected 3-4 astrometric doubles that will be

discovered will be invaluable in that they will be the first systems

from which gravitational masses of metal-poor stars at the bottom of the

main sequence can be directly measured.



WFC3/UVI 11657



The Population of Compact Planetary Nebulae in the Galactic Disk



We propose to secure narrow- and broad-band images of compact planetary

nebulae (PNe) in the Galactic Disk to study the missing link of the

early phases of post-AGB evolution. Ejected AGB envelopes become PNe

when the gas is ionized. PNe expand, and, when large enough, can be

studied in detail from the ground. In the interim, only the HST

capabilities can resolve their size, morphology, and central stars. Our

proposed observations will be the basis for a systematic study of the

onset of morphology. Dust properties of the proposed targets will be

available through approved Spitzer/IRS spectra, and so will the

abundances of the alpha-elements. We will be able thus to explore the

interconnection of morphology, dust grains, stellar evolution, and

populations. The target selection is suitable to explore the nebular and

stellar properties across the Galactic Disk, and to set constraints on

the galactic evolutionary models through the analysis of metallicity and

population gradients.



FLIGHT OPERATIONS SUMMARY:



Significant Spacecraft Anomalies: (The following are preliminary reports

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



HSTARS:

11954 COS Dib scidata overflow (LDOVRFLW) out of limits for 6 minutes

at 209/11:50:23.



COMPLETED OPS REQUEST:

18604-0 - 8051 History Buffer Snapshot

18605-0 - 8051 Min/Max Buffer Monitoring and Reset

18643-1 - NCS Restart and Cooldown (steps 12-44) @ 210/0204z

18647-0 - Mask K2 SPA Trim Relays and Set TCINIYT to 2 @ 209/1211z

18657-0 - Genslew for proposal 11474 (slot #5) @ 209/1552



COMPLETED OPS NOTES: (NONE)



SCHEDULED SUCCESSFUL

FGS GSAcq 4 4

FGS REAcq 12 12

OBAD with Maneuver 4 4



SIGNIFICANT EVENTS:

NICMOS Cooling System Restart: The NCS recovery attempt began @ 209 12:11z

with an EPS taper charge system modification to accommodate the expected

increase in vehicle load when NCS is restarted; a successful circulator start

@ 209/12:17z; and a successful compressor start @ 209/13:24z. 12.5 hours

after the successful compressor start (and ~4.5 after the compressor ramp),

the NCS Cooldown halted by the NCC safing @ 210/01:54z due to a low limit

violation for the Turbo Alternator speed.