HUBBLE SPACE TELESCOPE - Continuing to Collect World Class Science

DAILY REPORT      #5068

PERIOD COVERED: 5am April 5 - 5am April 6, 2010 (DOY 095/09:00z-096/09:00z)

OBSERVATIONS SCHEDULED

ACS/WFC 11995

CCD Daily Monitor (Part 2)

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 320 orbits (20 weeks) from 1 February 2010 to 20 June

2010.

ACS/WFC3 11599

Distances of Planetary Nebulae from SNAPshots of Resolved Companions

Reliable distances to individual planetary nebulae (PNe) in the Milky

Way are needed to advance our understanding of their spatial

distribution, birthrates, influence on galactic chemistry, and the

luminosities and evolutionary states of their central stars (CSPN). Few

PNe have good distances, however. One of the best ways to remedy this

problem is to find resolved physical companions to the CSPN and measure

their distances by photometric main-sequence fitting. We have previously

used HST to identify and measure probable companions to 10 CSPN, based

on angular separations and statistical arguments only. We now propose to

use HST to re-observe 48 PNe from that program for which additional

companions are possibly present. We then can use the added criterion of

common proper motion to confirm our original candidate companions and

identify new ones in cases that could not confidently be studied before.

We will image the region around each CSPN in the V and I bands, and in

some cases in the B band. Field stars that appear close to the CSPN by

chance will be revealed by their relative proper motion during the 13+

years since our original survey, leaving only genuine physical

companions in our improved and enlarged sample. This study will increase

the number of Galactic PNe with reliable distances by 50 percent and

improve the distances to PNe with previously known companions.

COS/FUV 11895

FUV Detector Dark Monitor

The purpose of this proposal is to monitor the FUV detector dark rate by

taking long science exposures without illuminating the detector. The

detector dark rate and spatial distribution of counts will be compared

to pre-launch and SMOV data in order to verify the nominal operation of

the detector. Variations of count rate as a function of orbital position

will be analyzed to find dependence of dark rate on proximity to the

SAA. Dependence of dark rate as function of time will also be tracked.

COS/NUV 11894

NUV Detector Dark Monitor

The purpose of this proposal is to measure the NUV detector dark rate by

taking long science exposures with no light on the detector. The

detector dark rate and spatial distribution of counts will be compared

to pre-launch and SMOV data in order to verify the nominal operation of

the detector. Variations of count rate as a function of orbital position

will be analyzed to find dependence of dark rate on proximity to the

SAA. Dependence of dark rate as function of time will also be tracked.

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.

S/C 12046

COS FUV DCE Memory Dump

Whenever the FUV detector high voltage is on, count rate and current

draw information is collected, monitored, and saved to DCE memory. Every

10 msec the detector samples the currents from the HV power supplies

(HVIA, HVIB) and the AUX power supply (AUXI). The last 1000 samples are

saved in memory, along with a histogram of the number of occurrences of

each current value.

In the case of a HV transient (known as a "crackle" on FUSE), where one

of these currents exceeds a preset threshold for a persistence time, the

HV will shut down, and the DCE memory will be dumped and examined as

part of the recovery procedure. However, if the current exceeds the

threshold for less than the persistence time (a "mini-crackle" in FUSE

parlance), there is no way to know without dumping DCE memory. By

dumping and examining the histograms regularly, we will be able to

monitor any changes in the rate of "mini-crackles" and thus learn

something about the state of the detector.

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/CCD 11852

STIS CCD Spectroscopic Flats C17

The purpose of this proposal is to obtain pixel-to-pixel lamp flat

fields for the STIS CCD in spectroscopic mode.

STIS/CCD 11853

Cycle 17 STIS CCD Imaging Flats

This program periodically monitors the STIS CCD imaging mode flat fields

by using the tungsten lamps.

STIS/CCD/MA2 11568

A SNAPSHOT Survey of the Local Interstellar Medium: New NUV Observations

of Stars with Archived FUV Observations

We propose to obtain high-resolution STIS E230H SNAP observations of

MgII and FeII interstellar absorption lines toward stars within 100

parsecs that already have moderate or high-resolution far-UV (FUV),

900-1700 A, observations available in the MAST Archive. Fundamental

properties, such as temperature, turbulence, ionization, abundances, and

depletions of gas in the local interstellar medium (LISM) can be

measured by coupling such observations. Due to the wide spectral range

of STIS, observations to study nearby stars also contain important data

about the LISM embedded within their spectra. However, unlocking this

information from the intrinsically broad and often saturated FUV

absorption lines of low-mass ions, (DI, CII, NI, OI), requires first

understanding the kinematic structure of the gas along the line of

sight. This can be achieved with high resolution spectra of high-mass

ions, (FeII, MgII), which have narrow absorption lines, and can resolve

each individual velocity component (interstellar cloud). By obtaining

short (~10 minute) E230H observations of FeII and MgII, for stars that

already have moderate or high- resolution FUV spectra, we can increase

the sample of LISM measurements, and thereby expand our knowledge of the

physical properties of the gas in our galactic neighborhood. STIS is the

only instrument capable of obtaining the required high resolution data

now or in the foreseeable future.

WFC3/UV 11635

Improve the Measurement of Vesta's Pole Orientation to Support Dawn

Mission

NASA?s Dawn spacecraft is scheduled to go into orbit around the main

belt asteroid 4 Vesta in July 2011. Currently the project is using a 3-?

pole position uncertainty of Vesta of 12? for spacecraft trajectory

design. We have determined that with an additional set of Hubble

observations at Vesta?s next opposition in February 2010, that the pole

position uncertainty can be reduced by a factor of 4. This will reduce

both cost and risk to the Dawn mission, and is likely to increase the

stay time at Vesta and will add to the scientific return of the mission.

The requested observing window in February 2010 is the last and single

best opportunity that can benefit the Dawn mission, but it is before the

start of the next HST Cycle.

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).

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               9              9

FGS REAcq               5              5

OBAD with Maneuver 4              4

SIGNIFICANT EVENTS: (None)