HUBBLE SPACE TELESCOPE - Continuing to Collect World Class Science

 

DAILY REPORT #5143

 

PERIOD COVERED: 5am July 21 - 5am July 22, 2010 (DOY 202/09:00z-203/09:00z)

 

FLIGHT OPERATIONS SUMMARY:

 

Significant Spacecraft Anomalies: (The following are preliminary reports

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

 

HSTARS: (None)

 

COMPLETED OPS REQUEST: (None)

 

COMPLETED OPS NOTES: (None)

 

                      SCHEDULED      SUCCESSFUL      

FGS GSAcq                 7                7

FGS REAcq                  9                9

OBAD with Maneuver   3                3

 

SIGNIFICANT EVENTS: (None)

 

 

OBSERVATIONS SCHEDULED:

 

ACS/WFC 11996

 

CCD Daily Monitor (Part 3)

 

This program comprises basic tests for measuring the read noise and dark

current of the ACS WFC and for tracking the growth of hot pixels. The

recorded frames are used to create bias and dark reference images for

science data reduction and calibration. This program will be executed

four days per week (Mon, Wed, Fri, Sun) for the duration of Cycle 17. To

facilitate scheduling, this program is split into three proposals. This

proposal covers 308 orbits (19.25 weeks) from 21 June 2010 to 1 November

2010.

 

STIS/CC 11845

 

CCD Dark Monitor Part 2

 

Monitor the darks for the STIS CCD.

 

STIS/CC 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/CC/MA 11668

 

Cosmo-chronometry and Elemental Abundance Distribution of the Ancient

Star HE1523-0901

 

We propose to obtain near-UV HST/STIS spectroscopy of the extremely

metal-poor, highly r-process-enhanced halo star HE 1523-0901, in order

to produce the most complete abundance distribution of the heaviest

stable elements, including platinum, osmium, and lead. These HST

abundance data will then be used to estimate the initial abundances of

the long-lived radioactive elements thorium and uranium, and by

comparison with their observed abundances, enable an accurate age

determination of this ancient star. The use of radioactive chronometers

in stars provides an independent lower limit on the age of the Galaxy,

which can be compared with alternative limits set by globular clusters

and by analysis from WMAP. Our proposed observations of HE1523-0901 will

also provide significant new information about the early chemical

history of the Galaxy, specifically, the nature of the first generations

of stars and the types of nucleosynthetic processes that occurred at the

onset of Galactic chemical evolution.

 

STIS/MA1/MA2 11857

 

STIS Cycle 17 MAMA Dark Monitor

 

This proposal monitors the behavior of the dark current in each of the

MAMA detectors.

 

The basic monitor takes two 1380s ACCUM darks each week with each

detector. However, starting Oct 5, pairs are only included for weeks

that the LRP has external MAMA observations planned. The weekly pairs of

exposures for each detector are linked so that they are taken at

opposite ends of the same SAA free interval. This pairing of exposures

will make it easier to separate long and short term temporal variability

from temperature dependent changes.

 

For both detectors, additional blocks of exposures are taken once every

six months. These are groups of five 1314s FUV-MAMA Time-Tag darks or

five 3x315s NUV ACCUM darks distributed over a single SAA-free interval.

This will give more information on the brightness of the FUV MAMA dark

current as a function of the amount of time that the HV has been on, and

for the NUV MAMA will give a better measure of the short term

temperature dependence.

 

WFC3/UV/ACS/WFC/IR 12058

 

A Panchromatic Hubble Andromeda Treasury - I

 

We propose to image the north east quadrant of M31 to deep limits in the

UV, optical, and near-IR. HST imaging should resolve the galaxy into

more than 100 million stars, all with common distances and foreground

extinctions. UV through NIR stellar photometry (F275W, F336W with

WFC3/UVIS, F475W and F814W with ACS/WFC, and F110W and F160W with

WFC3/NIR) will provide effective temperatures for a wide range of

spectral types, while simultaneously mapping M31's extinction. Our

central science drivers are to: understand high-mass variations in the

stellar IMF as a function of SFR intensity and metallicity; capture the

spatially-resolved star formation history of M31; study a vast sample of

stellar clusters with a range of ages and metallicities. These are

central to understanding stellar evolution and clustered star formation;

constraining ISM energetics; and understanding the counterparts and

environments of transient objects (novae, SNe, variable stars, x-ray

sources, etc.). As its legacy, this survey adds M31 to the Milky Way and

Magellanic Clouds as a fundamental calibrator of stellar evolution and

star-formation processes for understanding the stellar populations of

distant galaxies. Effective exposure times are 977s in F275W, 1368s in

F336W, 4040s in F475W, 4042s in F814W, 699s in F110W, and 1796s in

F160W, including short exposures to avoid saturation of bright sources.

These depths will produce photon-limited images in the UV. Images will

be crowding-limited in the optical and NIR, but will reach below the red

clump at all radii. The images will reach the Nyquist sampling limit in

F160W, F475W, and F814W.

 

WFC3/UVI 11615

 

Hunting for Optical Companions to Binary MSPs in Globular Clusters

 

Here we present a proposal which exploits the renewed potential of HST

after the Service Mission 4 for probing the population of binary

Millisecond Pulsars (MSPs) in Globular Clusters. In particular we intend

to: (1) extend the search for optical counterparts in Terzan 5, by

pushing the performance of the WFC3 IR channel to sample the entire MS

extension down to M=0.1 Mo; (2) perform a deep multi-band search of MSP

companions with the WFC3, in 3 clusters (namely NGC6440, M28 and M5),

where recent radio observations have found particularly interesting

objects; (3) derive an accurate radial velocity (with STIS) of the

puzzling optical companion COM6266B recently discovered by our group, to

firmly assess its cluster membership. This program is the result of a

large collaboration among the three major groups (lead by Freire, Ransom

and Possenti) which are performing extensive MSP search in GCs in the

radio bands, and our group which has a large experience in performing

accurate stellar photometry in crowded environments. This collaboration

has produced a number of outstanding discoveries. In fact, three of the

6 optical counterparts to binary MSP companions known to date in GCs

have been discovered by our group. The observations here proposed would

easily double/triple the existing sample of known MSP companions,

allowing the first meaningful approach to the study of the formation,

evolution and recycling process of pulsar in GCs. Moreover, since most

of binary MSPs in GCs are thought to form via stellar interactions in

the high density core regions, the determination of the nature of the

companion and the incidence of this collisionally-induced population has

a significant impact on our knowledge of the cluster dynamics. Even more

interesting, the study of the optical companions to NSs in GCs allows

one to derive tighter constraints (than those obtainable for NS binaries

in the Galactic field) on the system properties. This has, in turn, an

intrinsic importance for fundamental physics, since it offers the

opportunity of measuring the mass of the NS and hence constraining the

equation of state of matter at the nuclear equilibrium density.

 

WFC3/UVIS 11907

 

UVIS Cycle 17 Contamination Monitor

 

The UV throughput of WFC3 during Cycle 17 is monitored via weekly

standard star observations in a subset of key filters covering 200-600nm

and F606W, F814W as controls on the red end. The data will provide a

measure of throughput levels as a function of time and wavelength,

allowing for detection of the presence of possible contaminants.

 

WFC3/UVIS/IR 11909

 

UVIS Hot Pixel Anneal

 

The on-orbit radiation environment of WFC3 will continually generate new

hot pixels. This proposal performs the procedure required for repairing

those hot pixels in the UVIS CCDs. During an anneal, the two-stage

thermo-electric cooler (TEC) is turned off and the four-stage TEC is

used as a heater to bring the UVIS CCDs up to ~20 deg. C. As a result of

the CCD warmup, a majority of the hot pixels will be fixed; previous

instruments such as WFPC2 and ACS have seen repair rates of about 80%.

Internal UVIS exposures are taken before and after each anneal, to allow

an assessment of the procedure's effectiveness in WFC3, provide a check

of bias, global dark current, and hot pixel levels, as well as support

hysteresis (bowtie) monitoring and CDBS reference file generation. One

IR dark is taken after each anneal, to provide a check of the IR

detector.

 

 

-Lynn                   cid:image001.jpg@01CA472D.CCA694D0

NASA office: 301-286-2876

__________________________________________________________
Lynn F. Bassford
Hubble Space Telescope
CHAMP Mission Operations Manager
CHAMP Flight Operations Team Manager
Lockheed Martin Mission Services (LMMS)

"...Hubble is the most significant science instrument of all time in terms of its productivity..."     Scott Altman @12:45pm 5/21/9 STS-125 Senate Subcommittee Hearing