Daily Report #4314

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 - Continuing to collect World Class Science

DAILY REPORT # 4314

PERIOD COVERED: UT March 07, 2007 (DOY 066)

OBSERVATIONS SCHEDULED

ACS/SBC 10862

Comprehensive Auroral Imaging of Jupiter and Saturn during the
International Heliophysical Year

A comprehensive set of observations of the auroral emissions from
Jupiter and Saturn is proposed for the International Heliophysical
Year in 2007, a unique period of especially concentrated measurements
of space physics phenomena throughout the solar system. We propose to
determine the physical relationship of the various auroral processes
at Jupiter and Saturn with conditions in the solar wind at each
planet. This can be accomplished with campaigns of observations, with
a sampling interval not to exceed one day, covering at least one solar
rotation. The solar wind plasma density approaching Jupiter will be
measured by the New Horizons spacecraft, and a separate campaign near
opposition in May 2007 will determine the effect of large-scale
variations in the interplanetary magnetic field {IMF} on the Jovian
aurora by extrapolation from near-Earth solar wind measurements. A
similar Saturn campaign near opposition in Jan. 2007 will combine
extrapolated solar wind data with measurements from a wide range of
locations within the Saturn magnetosphere by Cassini. In the course of
making these observations, it will be possible to fully map the
auroral footprints of Io and the other satellites to determine both
the local magnetic field geometry and the controlling factors in the
electromagnetic interaction of each satellite with the corotating
magnetic field and plasma density. Also in the course of making these
observations, the auroral emission properties will be compared with
the properties of the near-IR ionospheric emissions {from ground-based
observations} and non thermal radio emissions, from ground-based
observations for Jupiter?s decametric radiation and Cassini plasma
wave measurements of the Saturn Kilometric Radiation {SKR}.

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.

NIC2 10802

SHOES-Supernovae, HO, for the Equation of State of Dark energy

The present uncertainty in the value of the Hubble constant {resulting
in an uncertainty in Omega_M} and the paucity of Type Ia supernovae at
redshifts exceeding 1 are now the leading obstacles to determining the
nature of dark energy. We propose a single, integrated set of
observations for Cycle 15 that will provide a 40% improvement in
constraints on dark energy. This program will observe known Cepheids
in six reliable hosts of Type Ia supernovae with NICMOS, reducing the
uncertainty in H_0 by a factor of two because of the smaller
dispersion along the instability strip, the diminished extinction, and
the weaker metallicity dependence in the infrared. In parallel with
ACS, at the same time the NICMOS observations are underway, we will
discover and follow a sample of Type Ia supernovae at z 1. Together,
these measurements, along with prior constraints from WMAP, will
provide a great improvement in HST's ability to distinguish between a
static, cosmological constant and dynamical dark energy. The Hubble
Space Telescope is the only instrument in the world that can make
these IR measurements of Cepheids beyond the Local Group, and it is
the only telescope in the world that can be used to find and follow
supernovae at z 1. Our program exploits both of these unique
capabilities of HST to learn more about one of the greatest mysteries
in science.

WFPC2 11083

The Structure, Formation and Evolution of Galactic Cores and Nuclei

A surprising result has emerged from the ACS Virgo Cluster Survey
{ACSVCS}, a program to obtain ACS/WFC gz imaging for a large, unbiased
sample of 100 early-type galaxies in the Virgo Cluster. On
subarcsecond scales {i.e., 0.1"-1"}, the HST brightness profiles vary
systematically from the brightest giants {which have nearly constant
surface brightness cores} to the faintest dwarfs {which have compact
stellar nuclei}. Remarkably, the fraction of galaxy mass contributed
by the nuclei in the faint galaxies is identical to that contributed
by supermassive black holes in the bright galaxies {0.2%}. These
findings strongly suggest that a single mechanism is responsible for
both types of Central Massive Object: most likely internally or
externally modulated gas inflows that feed central black holes or lead
to the formation of "nuclear star clusters". Understanding the history
of gas accretion, star formation and chemical enrichment on
subarcsecond scales has thus emerged as the single most pressing
question in the study of nearby galactic nuclei, either active or
quiescent. We propose an ambitious HST program {199 orbits} that
constitutes the next, obvious step forward: high-resolution,
ultraviolet {WFPC2/F255W} and infrared {NIC1/F160W} imaging for the
complete ACSVCS sample. By capitalizing on HST's unique ability to
provide high-resolution images with a sharp and stable PSF at UV and
IR wavelengths, we will leverage the existing optical HST data to
obtain the most complete picture currently possible for the history of
star formation and chemical enrichment on these small scales. Equally
important, this program will lead to a significant improvement in the
measured structural parameters and density distributions for the
stellar nuclei and the underlying galaxies, and provide a sensitive
measure of "frosting" by young stars in the galaxy cores. By virtue of
its superb image quality and stable PSF, NICMOS is the sole instrument
capable of the IR observations proposed here. In the case of the WFPC2
observations, high-resolution UV imaging { 0.1"} is a capability
unique to HST, yet one that could be lost at any time.

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 10 10
FGS REacq 04 04
OBAD with Maneuver 28 28

SIGNIFICANT EVENTS: (None)