HUBBLE
SPACE TELESCOPE - Continuing to collect World Class Science
DAILY
REPORT # 4518
PERIOD
COVERED: UT January 02, 2008 (DOY 002)
OBSERVATIONS
SCHEDULED
ACS/SBC
11145
Probing
the Planet Forming Region of T Tauri Stars in Chamaeleon
By studying
the inner, planet-forming regions of circumstellar disks
around
low-mass pre- main sequence stars we can refine theories of giant
planet
formation and develop timescales for the evolution of disks and
their
planets. Spitzer infrared observations of T Tauri stars in the
Chamaeleon
star-forming region have given us an unprecedented look at
dust
evolution in young objects. However, despite this ground breaking
progress
in studying the dust in young disks, the gas properties of the
inner
disk remain essentially unknown. Using ACS on HST, we propose to
measure
the H_2 emission originating in the innermost disk regions of
classical
T Tauri stars in different stages of evolution with the
objective
of revealing the timescales of gas dissipation and its
relationship
to dust evolution. This proposal is part of a comprehensive
effort
with approved programs on Spitzer, Gemini, and Magellan that aim
to
characterize the state of gas and dust in disks where planets may
already
have formed.
ACS/SBC
11309
Chemical
Composition of an Exo-Neptune
The
recent discovery that the
its
host star has presented us the first chance to observationally study
ice
giant formation beyond our solar system {Gillon et al. 2007}. Using
Directors
Discretionary time, we propose to obtain a high-precision
light
curve of the GJ 436 b transit with the FGS in order to improve the
current
radius determination for this planet. Measuring a precise radius
for
GJ 436 b will allow us to ascertain whether the planet has a pure
water
vapor or H/He envelope like Uranus and Neptune. Knowing this will
constrain
its formation and evolution and help place our own solar
system
ice giants in a broader context. Additionally, a precise radius
for
GJ 436 b will be a necessity for interpreting the certain follow-up
observations
of this unique system.
FGS
11212
Filling
the Period Gap for Massive Binaries
The
current census of binaries among the massive O-type stars is
seriously
incomplete for systems in the period range from years to
millennia
because the radial velocity variations are too small and the
angular
separations too close for easy detection. Here we propose to
discover
binaries in this observational gap through a Faint Guidance
Sensor
SNAP survey of relatively bright targets listed in the Galactic O
Star
Catalog. Our primary goal is to determine the binary frequency
among
those in the cluster/association, field, and runaway groups. The
results
will help us assess the role of binaries in massive star
formation
and in the processes that lead to the ejection of massive
stars
from their natal clusters. The program will also lead to the
identification
of new, close binaries that will be targets of long term
spectroscopic
and high angular resolution observations to determine
their
masses and distances. The results will also be important for the
interpretation
of the spectra of suspected and newly identified binary
and
multiple systems.
FGS
11213
Distances
to Eclipsing M Dwarf Binaries
We
propose HST FGS observations to measure accurate distances of 5
nearby
M dwarf eclipsing binary systems, from which model-independent
luminosities
can be calculated. These objects have either poor or no
existing
parallax measurements. FGS parallax determinations for these
systems,
with their existing dynamic masses determined to better than
0.5%,
would serve as model-independent anchor points for the low-mass
end
of the mass-luminosity diagram.
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 DARKs. 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
11166
The
Mass-dependent Evolution of the Black Hole-Bulge Relations
In
the local universe, the masses of giant black holes are correlated
with
the luminosities, masses and velocity dispersions of their host
galaxy
bulges. This indicates a surprisingly close connection between
the
evolution of galactic nuclei (on parsec scales) and of stars on kpc
scales.
A key observational test of proposed explanations for these
correlations
is to measure how they have evolved over cosmic time. Our
ACS
imaging of 20 Seyfert 1 galaxies at z=0.37 showed them to have
smaller
bulges (by a factor of 3) for a given central black hole mass
than
is found in galaxies in the present-day universe. However, since
all
our sample galaxies had black hole masses in the range 10^8.0--8.5
Msun,
we could only measure the OFFSET in black hole mass to bulge
luminosity
ratios from the present epoch. By extending this study to
black
hole masses another factor of 10 lower, we propose to determine
the
full CORRELATION of black hole mass with host galaxy properties at a
lookback
time of 4 Gyrs and to test mass-dependency of the evolution. We
have
selected 14 Seyfert galaxies from SDSS DR5 whose narrow Hbeta
emission
lines (and estimated nuclear luminosities) imply that they have
black
hole masses around 10^7 Msuns. We will soon complete our Keck
spectroscopic
measures of their bulge velocity dispersions. We need a
1-orbit
NICMOS image of each galaxy to separate its nonstellar
luminosity
from its bulge and disk. This will allow us to make the first
determination
of the full black hole/bulge relations at z=0.37 (e.g. M-L
and
M-sigma), as well as a test of whether active galaxies obey the
Fundamental
Plane relation at that epoch.
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.
NIC3
11334
NICMOS
Cycle 16 Spectrophotometry
Observation
of the three primary WD flux standards must be repeated to
refine
the NICMOS absolute calibration and monitor for sensitivity
degradation.
So far, NICMOS grism spectrophotometry is available for
only
~16 stars with good STIS spectra at shorter wavelengths. There are
more
in the HST CALSPEC standard star data base with good STIS spectra
that
would also become precise IR standards with NICMOS absolute SED
measurements.
Monitoring the crucial three very red stars (M, L, T) for
variability
and better S/N in the IR. Apparent variability was
discovered
at shorter wavelengths during the ACS cross-calibration work
that
revealed a ~2% discrepancy of the cool star fluxes with respect to
the
hot primary WD standards. About a third of these stars are bright
enough
to do in one orbit, the rest require 2 orbits.
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
09
09
FGS
REacq
05
05
OBAD
with Maneuver
28
28
SIGNIFICANT
EVENTS: (None)