Status Report

HST Daily Report # 3290

By SpaceRef Editor
January 30, 2003
Filed under , ,






NICMOS Post-SAA calibration – CR Persistence Part 1.

A new procedure proposed to alleviate the CR-persistence problem of NICMOS.
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
darks will be non-standard reference files available to users with a USEAFTER
date/time mark.


Towards a global understanding of accretion physics –, Clues from an UV
spectroscopic survey of cataclysmic variables

Accretion inflows and outflows are fundamental phenomena in a wide variety of
astrophysical environments, such as Young Stellar Objects, galactic binaries,
and AGN. Observationally, cataclysmic variables {CVs} are particularly well
suited for the study of accretion processes. We propose to carry out a STIS UV
spectroscopic snapshot survey of CVs that fully exploits the diagnostic
potential of these objects for our understanding of accretion physics. This
survey will provide an homogenous database of accretion disc and wind outflow
spectra covering a wide range of mass transfer rates and binary
inclinations. We
will analyse these spectra with state-of-the-art accretion disc model spectra
{SYNDISK}, testing our current knowledge of the accretion disc structure, and,
thereby, providing new insight into the so far not well understood process of
viscous dissipation. We will use our parameterised wind model PYTHON for the
analysis of the radiation driven accretion disc wind spectra, assessing the
fundamental question whether the mass loss rate correlates with the disc
luminosity. In addition, our survey data will identify a number of systems in
which the white dwarf significantly contributes to the UV flux, permitting an
analysis of the impact of mass accretion on the evolution of these compact
stars. This survey will at least double, if not triple, the number of
high-quality accretion disc / wind outflow / accreting white dwarf spectra, and
we waive our proprietary rights to permit a timely use of this database.

ACS/WFC 9433

The Size Distribution of Kuiper Belt Bodies

The Kuiper Belt is a population of remnant planetesimals from the formation of
the Solar System. Since the planetesimals in extrasolar systems are too
faint to
see with present or planned telescopes, the Kuiper Belt is our best chance to
test models of accretional/collisional evolution against observations. Current
ground-based observations of Kuiper Belt Objects {KBOs} are consistent with a
pure power law size distribution N{D}propto D^-q, q~4.3. Current accretion
models predict a break to a shallower slope q=3.5 for objects of diameter
D<~100 km. We will conduct a survey of 6 ACS/WFC fields to detect KBOs with R<28.5, and diameters as small as D~10 km. The number of KBOs at these small sizes, unmeasurable from the ground, will test the existence of the predicted break with 95% confidence---we expect between 12 and 50 detections. A census of small KBOs is also important in confirming the idea that short-period comets are errant KBOs. With HST and ground- based followup, we can determine orbital parameters for the detected KBOs, and search for dynamical populations which may be deficient in D>100 km KBOs and hence not yet detected. In particular, we
determine whether the current absence of objects with perihelia beyond 50 AU is
due to a truncation of the protoplanetary disk at some point in Solar System
history, or just a failure to accrete D>150 km objects.

WFPC2 9594


This dark calibration program obtains 3 dark frames every day to provide data
for monitoring and characterizing the evolution of hot pixels

STIS 9605

CCD Dark Monitor-Part 1

Monitor the darks for the STIS CCD

STIS 9607

CCD Bias Monitor – Part 1

Monitor the bias in the 1×1, 1×2, 2×1, and 2×2 bin settings at gain=1, and 1×1
at gain = 4, to build up high-S/N superbiases and track the evolution of hot

STIS 9615

Cycle 11 MAMA Dark Monitor

This test performs the routine monitoring of the MAMA detector dark noise. This
proposal will provide the primary means of checking on health of the MAMA
detectors systems through frequent monitoring of the background count rate. The
purpose is to look for evidence of change in dark indicative of detector


Cycle 11 NICMOS dark current, shading profile, and read noise monitoring

The purpose of this proposal is to monitor the dark current, read noise, and
shading profile for all three NICMOS detectors throughout the duration of Cycle
11. This proposal is a continuation of PID 9321 which covers the period between
the end of SMOV3B and the onset of Cycle 11.

ACS 9673

CCD Daily Monitor

This program consists of basic tests to monitor, the read noise, the
of hot pixels and test for any source of noise in ACS CCD detectors. This
programme will be executed once a day for the entire lifetime of ACS

WFPC2 9676

POMS Test Proposal: WFII parallel archive proposal

This is the generic target version of the WFPC2 Archival Pure Parallel program.
The program will be used to take parallel images of random areas of the sky,
following the recommendations of the 2002 Parallels Working Group.

STIS 9706

STIS Pure Parallel Imaging Program: Cycle 10

This is the default archival pure parallel program for STIS during cycle 10.


Significant Spacecraft Anomalies: (The following are preliminary reports of
potential non-nominal performance that will be investigated.) None



                        SCHEDULED     SUCCESSFUL    FAILURE TIMES
FGS GSacq            6                         6
FGS REacq            11                       11
FHST Update          6                         6


SpaceRef staff editor.