NASA Hubble Space Telescope Daily Report # 4384
Notice: For the foreseeable future, the daily reports may contain apparent discrepancies between some proposal descriptions and the listed instrument usage. This is due to the conversion of previously approved ACS WFC or HRC observations into WFPC2, or NICMOS observations subsequent to the loss of ACS CCD science capability in late January.
HUBBLE SPACE TELESCOPE DAILY REPORT # 4384
– Continuing to collect World Class Science
PERIOD COVERED: UT June 14, 2007 (DOY 165)
OBSERVATIONS SCHEDULED
FGS 10927
The Weight-Watcher Program for Subdwarfs
We propose to use HST/FGS1r to measure five subdwarf spectroscopic binaries to determine masses for the components. Their metallicities, [Fe/H], range from -0.5 to -2.5, and their projected minimum separations range from 9 to 24 mas. These binaries are resolvable with HST/FGS1r but not any ground-based technique. Currently, there are only two subdwarf systems having any mass measurements. The proposed work will boost the total number of subdwarf systems with masses from two to seven, and allow us to construct the first mass-luminosity relation for low-metallicity stars.
NIC1/NIC2/NIC3 8794
NICMOS Post-SAA calibration – CR Persistence Part 5
A new procedure proposed to alleviate the CR-persistence problem of NICMOS. Dark frames will be obtained immediately upon exiting the SAA contour 23, and every time a NICMOS exposure is scheduled within 50 minutes of coming out of the SAA. The darks will be obtained in parallel in all three NICMOS Cameras. The POST-SAA darks will be non- standard reference files available to users with a USEAFTER date/time mark. The keyword ‘USEAFTER=date/time’ will also be added to the header of each POST-SAA DARK frame. The keyword must be populated with the time, in addition to the date, because HST crosses the SAA ~8 times per day so each POST-SAA DARK will need to have the appropriate time specified, for users to identify the ones they need. Both the raw and processed images will be archived as POST-SAA DARKSs. Generally we expect that all NICMOS science/calibration observations started within 50 minutes of leaving an SAA will need such maps to remove the CR persistence from the science images. Each observation will need its own CRMAP, as different SAA passages leave different imprints on the NICMOS detectors.
NIC3 10996
NICMOS J-band Imaging of Strongly Lensing Clusters
We propose to use deep imaging in the F110W {‘J’} band over a large area to search for highly magnified galaxies around massive lensing clusters.
WFPC2 10818
Very Young Globular Clusters in M31 ?
We propose to use HST’s unique high spatial resolution imaging capabilities to conclusively confirm or refute the presence of alleged very young globular clusters in M31. Such young globular clusters with ages < 3 Gyr are not present in our galaxy, and, if real, would lead to a striking difference in the age distribution of the GCs between M31 and the Millky Way. If the apparent presence of very young globular clusters in M31 is confirmed through our proposed ACS imaging {now WFPC2 imaging} with HST, this would suggest major differences in the history of assembly of the two galaxies, with probable substantial late accretion into M31 which did not occur in our own galaxy.
WFPC2 11084
Probing the Least Luminous Galaxies in the Local Universe
We propose to obtain deep color-magnitude data of eight new Local Group galaxies which we recently discovered: Andromeda XI, Andromeda XII, and Andromeda XIII {satellites of M31}; Canes Venatici I, Canes Venatici II, Hercules, and Leo IV {satellites of the Milky Way}; and Leo T, a new “free-floating” Local Group dwarf spheroidal with evidence for recent star formation and associated H I gas. These represent the least luminous galaxies known at *any* redshift, and are the only accessible laboratories for studying this extreme regime of galaxy formation. With deep WFPC-2 F606W and F814W pointings at their centers, we will determine whether these objects contain single or multiple age stellar populations, as well as whether these objects display a range of metallicities.
FLIGHT OPERATIONS SUMMARY:
Significant Spacecraft Anomalies: (The following are preliminary reports of potential non-nominal performance that will be investigated.) HSTARS: 10862 – GSacq(2,1,1) failed to RGA control.
GSacq(2,1,1) scheduled at 166/05:12:52 failed at 05:16:35 due to scan step limit exceeded on FGS 2. OBAD1 showed errors of V1=-433.76, V2=-3218.95, V3=691.56,and RSS= 3320.85. OBAD2 showed errors of V1=-2.74, V2=-10.01, V3=9.53, and RSS= 14.09. the map at 05:20:22 showed errors of V1=-0.61, V2=7.16, V3=3.43, and RSS = 7.96.
COMPLETED OPS REQUEST: (None)
SCHEDULED SUCCESSFUL FGS GSacq 8 7 FGS REacq 6 6 OBAD with Maneuver 28 28
COMPLETED OPS NOTES: (None)
SIGNIFICANT EVENTS: (None)
