Daily Report #4374

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 # 4374

PERIOD COVERED: UT May 31, 2007 (DOY 151)

OBSERVATIONS SCHEDULED

WFPC2 10877

A Snapshot Survey of the Sites of Recent, Nearby Supernovae

During the past few years, robotic {or nearly robotic} searches for
supernovae {SNe}, most notably our Lick Observatory Supernova Search {LOSS},
have found hundreds of SNe, many of them in quite nearby galaxies {cz 4000
km/s}. Most of the objects were discovered before maximum brightness, and
have follow-up photometry and spectroscopy; they include some of the
best-studied SNe to date. We propose to conduct a snapshot imaging survey of
the sites of some of these nearby objects, to obtain late-time photometry
that {through the shape of the light and color curves} will help reveal the
origin of their lingering energy. The images will also provide
high-resolution information on the local environments of SNe that are far
superior to what we can procure from the ground. For example, we will obtain
color-color and color-magnitude diagrams of stars in these SN sites, to
determine the SN progenitor masses and constraints on the reddening.
Recovery of the SNe in the new HST images will also allow us to actually
pinpoint their progenitor stars in cases where pre- explosion images exist
in the HST archive. This proposal is an extension of our successful Cycle 13
snapshot survey with ACS. It is complementary to our Cycle 15 archival
proposal, which is a continuation of our long-standing program to use
existing HST images to glean information about SN environments.

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}.

ACS/SBC 10872

Lyman Continuum Emission in Galaxies at z=1.2

Lyman continuum photons produced in massive starbursts may have played a
dominant role in the reionization of the Universe. Starbursts are important
contributors to the ionizing metagalactic background at lower redshifts as
well. However, their contribution to the background depends upon the
fraction of ionizing radiation that escapes from the intrinsic opacity of
galaxies below the Lyman limit. Current surveys suggest escape fractions of
a few percent, up to 10%, with very few detections {as opposed to upper
limits} having been reported. No detections have been reported in the epochs
between z=0.1 and z=2. We propose to measure the fraction of escaping Lyman
continuum radiation from 15 luminous z~1.2 galaxies in the GOODS fields.
Using the tremendous sensitivity of the ACS Solar- blind Channel, we will
reach AB=30 mag., allowing us to detect an escape fraction of 1%. We will
correlate the amount of escaping radiation with the photometric and
morphological properties of the galaxies. A non-detection in all sources
would imply that QSOs provide the overwhelming majority of ionizing
radiation at z=1.3, and it would strongly indicate that the properties of
galaxies at higher redshift have to be significantly different for galaxies
to dominate reionization. The deep FUV images will also be useful for
extending the FUV study of other galaxies in the GOODS fields.

FGS 10929

Calibrating the Mass-Luminosity Relation at the End of the Main Sequence

We propose to use HST-FGS1R to finish calibrating the mass-luminosity
relation for stars less massive than 0.5 Msun, with special emphasis on
objects near the stellar/substellar border. Our goals are to determine Mv
values to 0.05 magnitude and masses to 5%, and thereby build the fundamental
database of stellar masses that we will use to test theoretical models as
never before. This program uses the combination of HST- FGS3/FGS1R at
optical wavelengths, historical infrared speckle data, ground-based parallax
work, metallicity studies, and radial velocity monitoring to examine nearby,
subarcsecond binary systems. The high precision separation and position
angle measurements with HST-FGS3/FGS1R {to 1 mas in the separations} for
these faint {V = 10-15} targets simply cannot be equaled by any ground-based
technique. As a result of these measurements, we are deriving high quality
luminosities and masses for the components in the systems, and
characterizing their spectral energy distributions from 0.5 to 2.2 microns.
One of the objects, GJ 1245 C with mass 0.074 +/- 0.002 Msun, is the only
object known with an accurate dynamical mass less than 0.10 Msun. The payoff
of this proposal is high because the six systems selected for final
observations in Cycles 15 and 16 have already been resolved during Cycles
5-13 with HST FGS3/FGS1R and contain most of the reddest objects for which
accurate dynamical masses can be determined.

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.

NIC3 11080

Exploring the Scaling Laws of Star Formation

As a variety of surveys of the local and distant Universe are approaching a
full census of galaxy populations, our attention needs to turn towards
understanding and quantifying the physical mechanisms that trigger and
regulate the large-scale star formation rates {SFRs} in galaxies.

FLIGHT OPERATIONS SUMMARY:

Significant Spacecraft Anomalies: (The following are preliminary reports of
potential non-nominal performance that will be investigated.)

HSTARS: (None from today)

10846 - GSAcq (1,2,2) requires multiple attempts to achieve CT-DV

During the PTAS data review processing data revealed that GSACq (1,2,2),
scheduled for 144:09:16:05, required four entries into CT before achieving
CT-DV. The acquisition was successful.

10845 - GSAcq (1,2,2) requires multiple attempts to achieve CT-DV

During the PTAS data review processing data revealed that GSAcq (1,2,2)
scheduled at 145:07:38:04, required two attempts to achieve CT-DV. The
acquisition was successful.

COMPLETED OPS REQUEST: (None)

SCHEDULED SUCCESSFUL

FGS GSacq 10 10
FGS REacq 01 01
OBAD with Maneuver 22 22

COMPLETED OPS NOTES: (None)