Status Report

Hubble Space Telescope Daily Report #3120 – 20 May 2002

By SpaceRef Editor
May 20, 2002
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HUBBLE SPACE TELESCOPE

DAILY REPORT # 3120

PERIOD COVERED: 0000Z (UTC) 05/19/02 – 0000Z (UTC) 05/20/02

OBSERVATIONS SCHEDULED AND ACCOMPLISHED:

NICMOS 8790

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.

STIS/CCD 8902

The Space Telescope Imaging Spectrograph (CCD) was used to monitor the darks.

STIS/CCD 8904

The Space Telescope Imaging Spectrograph (CCD) was used to 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 in order
to build up high-S/N superbiases and track the evolution of hot columns.

STIS/CCD 8905

The Space Telescope Imaging Spectrograph (CCD) was used to measure the read
noise of all the amplifiers {A, B, C, D} on the STIS CCD using pairs of bias
frames. Full frame and binned observations are made in both Gain 1 and Gain 4,
with binning factors of 1×1, 1×2, 2×1 and 2×2. All exposures are internals.

STIS/CCD/MA1/MA2 8916

The Space Telescope Imaging Spectrograph (CCD, MA1 and MA2) was used to measure
the basic sensitivity for all supported MAMA and CCD first-order spectroscopic
modes. Sensitivity measurements are done for all supported tilts of the
gratings, at a S/N suitable to any particular setting, in order to get all
measurements done in a reasonable number of orbits but still get a very
accurate
sensitivity measurement.

STIS/MA1/MA2 8920

The Space Telescope Imaging Spectrograph (MA1 and MA2) was used to perform the
routine monitoring of the MAMA detector dark noise, and is the primary means of
checking on health of the MAMA detectors systems through frequent monitoring of
the background count rate.

WF/PC-2 8935

The WF/PC-2 was used to obtain dark frames every week in order to provide data
for the ongoing calibration of the CCD dark current rate, and to monitor and
characterize the evolution of hot pixels. Over an extended period these data
will also provide a monitor of radiation damage to the CCDs.

WFPC2 8938

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

WF/PC-2 8939

The WF/PC-2 was used to calibrate the internal monitor, to be run weekly to
monitor the health of the cameras.

ACS/WFC/HRC 8947

The Advanced Camera for Surveys (WFC and HRC) was used to perform basic
tests to
monitor, the read noise, the development of hot pixels and test for any source
of noise in ACS CCD detectors. This program will be executed at least once
a day
for the entire lifetime of ACS.

ACS/SBC 9009

The Advanced Camera for Science (SBC) was used to perform a MAMA fold analysis
for initial turn-on or anomalous recovery of the MAMA detector.

WF/PC-2 9043

The WF/PC-2 was used to continue observations in the HST Key Project on the
Extragalactic Distance Scale and the HST project on the “Calibration of Nearby
Type Ia Supernovae” that have greatly improved our knowledge of the Hubble
Constant by providing a solid zero point for the Tully- Fisher {TF}
relation and
Type Ia Supernovae {SNIa}. However, severe inconsistencies remain for distance
estimators to early-type galaxies such as surface brightness fluctuations
{SBF},
the planetary nebula luminosity function {PNLF}, the fundamental plane
{FP}, and
the globular cluster luminosity function {GCLF}. As a result, the distance to
the Virgo cluster core remains uncertain by as much as 20 determination is
directly affected by a lingering 0.1 mag {5 uncertainty in the photometric
calibration of the WFPC2. Resolving these issues is essential not only to firm
up the extragalactic distance scale, but also to understand the mass and
velocity structure of the local universe. SBF in particular is emerging as the
method of choice for mapping local velocity fields to 10, 000 kms because it
offers an order of magnitude less Malmquist bias than TF, and SNIa are too rare
to study large scale flows effectively. This project will tighten the
photometric calibration of the WFPC2, and provide a solid Cepheid calibration
for SBF and PNLF.

ACS/WFC/HRC 9075

The Advanced Camera for Surveys (WFC and HRC) was used to obtain a Hubble
diagram of Type Ia supernovae {SNe Ia} that will be of long lasting value as a
record of the expansion history of the universe.

STIS/CCD 9110

The Space Telescope Imaging Spectrograph (CCD) was used to investigate whether
the large number of collisions thought to have taken place in the primordial
Kuiper belt suggest that many Kuiper belt objects {KBOs} could have suffered
binary-forming collisions similar to that which formed the Pluto — Charon
binary. Detection of such KBO satellites would allow measurement of KBO masses,
would help to understand the past collisional environment of the Kuiper belt,
and would give a context to the otherwise unique-seeming formation of the Pluto
— Charon binary.

NICMOS 9269

NICMOS Camera 3 pure parallel exposures in the F222M filter will be
obtained for
the entire duration of SMOV to establish the stability of the
HST+NCS+Instrument
thermal emission.

STIS/CCD 9317

The Space Telescope Imaging Spectrograph (CCD) was used to perform the default
archival pure parallel program for STIS during cycle 10.

WF/PC-2 9318

The WF/PC-2 was used to perform the generic target version of the WFPC2
Archival
Pure Parallel program. The program was used to take parallel images of random
areas of the sky, following the recommendations of the Parallels Working
Group.

ACS/WFC/HRC 9566

The Advanced Camera for Surveys (WFC and HRC) was used to perform hot pixel
annealing that will be performed once per month. The CCD TECs will be
turned off
and heaters will be activated to bring the WFC detector temperature to about
+10C. The HRC temperature will reach about 30C. This state will be held for
approximately 24 hours, after which the heaters are turned off, the TECs turned
on, and the CCDs returned to normal operating condition.

ACS/WFC 9587

The Advanced Camera for Surveys (WFC) was used to observe V838 Mon0cerotis
which
is a completely unanticipated new kind of object: although it has undergone an
outburst somewhat similar to that of an extremely slow nova, its spectrum is
unique and totally unlike that of any type of nova. Knowledge of its distance
and luminosity is crucial in understanding its nature and origin. Remarkably, a
rapidly evolving light echo around V838 Monocerotis has been detected from the
ground in recent weeks. HST polarimetric imaging over the next few months, as
the light echo expands and fades, will provide a direct geometrical distance to
this object. Since the only previous Galactic nova light echoes occurred in
1901
and 1936, this extraordinary combination of circumstances is unlikely to recur
during the HST mission.

ACS/WFC 9588

V838 Mon is a completely unanticipated new kind of object: although it has
undergone an outburst somewhat similar to that of an extremely slow nova, its
spectrum is unique and totally unlike that of any type of nova. Knowledge
of its
distance and luminosity is crucial in understanding its nature and origin.
Remarkably, a rapidly evolving light echo around V838 Mon has been detected
from
the ground in recent weeks. HST polarimetric imaging over the next few months,
as the light echo expands and fades, will provide a direct geometrical distance
to this object {because polarization allows us to selectively identify material
with a scattering angle of 90 deg, lying in the plane of the sky at the same
distance as the star}. The outburst of V838 Mon thus provides a magnificent,
unique, and unexpected testbed for the method proposed by Sparks for measuring
extragalactic distances using supernova light echoes, which was the primary
justification for adding polarimetric capabilities to the Advanced Camera for
Surveys. Since the only previous Galactic nova light echoes occurred in
1901 and
1936, this extraordinary combination of circumstances is unlikely to recur
during the HST mission

FLIGHT OPERATIONS SUMMARY:

HSTARs:

8654 – GSACQ(2,3,2) failed to RGA Mode @ 140/1803z

8655 – GCSS3T out of limit one sample @ 140/2329z

COMPLETED OPS REQs:

None

OPS NOTES EXECUTED:

None

                  SCHEDULED     SUCCESSFUL    FAILURE TIMES
FGS GSacq 6 5 140/1803z (see HSTAR 8654)
FGS REacq 10 9 140/1910z
FHST Update 9 9
LOSS of LOCK None

Operations Notes:

Ephemeris U/L postponed due to ‘Accuracy Check Failure’

SIGNIFICANT FORTHCOMING EVENTS:

Continuation of Servicing Mission Orbital Verification and the gradual
resumption of normal science observations and calibrations

SpaceRef staff editor.