HUBBLE
SPACE TELESCOPE - Continuing to Collect World Class Science
DAILY
REPORT #4929
PERIOD
COVERED: 5am September 11 - 5am September 14, 2009 (DOY 254/09:00z-257/09:00z)
OBSERVATIONS
SCHEDULED
WFC3/UVIS
11998
Determining
the Rotational Phase of Comet 9P/Tempel 1 in Support of the
StardustNExT
Mission
A
primary objective of the StardustNExT mission is to image the crater
created
by NASA's Deep Impact (DI) mission. The 12-year ground- and
space-based
DI observing campaign provided an exceptional data set for
investigating
the rotation of comet 9P/Tempel 1. The just-completed
analysis
shows that the spin period increased in a stepwise manner
through
the perihelia in 2000 and 2005, due to an outgassing of water
from
a southern jet. Our water-sublimation jet torque model has been
moderately
successful in predicting the integrated change in the nucleus
longitude
at the 2005 perihelion and beyond, and has been used to
predict
the rotation state at the planned Stardust-NExT encounter just
after
perihelion on 02/14/2011. We propose a 19-orbit Hubble program to
perform
light curve observations of 9P/Tempel 1 that will allow us to
determine
the time-of-arrival adjustment of the Stardust-NExT spacecraft
trajectory
that is needed to ensure that the spacecraft arrives at
encounter
with the (as yet unseen) artificial DI crater at the
sub-spacecraft
point and fully illuminated by the sun. The trajectory
correction
maneuver is in Feb 2010, and we need to know the nucleus
rotation
phase to a precision of 1% and the period to 10 sec by Jan
2010.
HST is the only facility capable of obtaining the high-quality
data
necessary to determine the shape and phase of the rotational light
curve.
When combined with ground-based data 2-3 months later, we will
achieve
the required precision.
FGS
11942
Increasing
the Accuracy of HST Astrometry with FGS1R
We
propose to observe six exoplanetary system host stars and two
planetary
nebulae central stars with FGS1R. All objects have been
previously
observed under proposals GO-09233, -09969, -10989, and
-11210.
These observations will significantly extend the time baseline,
permitting
improvements in the determination of proper motion. This
systematic
motion must be removed to get at the perturbation of
interest,
either due to exoplanetary companions or the orbital motion of
the
Earth (parallax). In most cases the perturbation orbits will also
improve.
We improve either companion mass or PN parallax. For one
target,
GJ 876, theoretical dynamical modelers have proposed an
inclination
closer to 50 degrees, while FGS3 measurements indicated an
inclination
closer to 84 degrees. These new data, once combined with our
older
FGS3 data, will permit an independent remeasurement of the
inclination
of the outermost companion, and a re- evaluation of widely
used
dynamical algorithms.
WFC3/UVIS
11935
UVIS
G280 Wavelength Calibration
Wavelength
calibration of the UVIS G280 grism will be established using
observations
of the Wolf Rayet star WR14. Accompanying direct exposures
will
provide wavelength zeropoints for dispersed exposures. The
calibrations
will be obtained at the central position of each CCD chip
and
at the center of the UVIS field. No additional field- dependent
variations
will be obtained.
WFC3/IR/S/C
11929
IR
Dark Current Monitor
Analyses
of ground test data showed that dark current signals are more
reliably
removed from science data using darks taken with the same
exposure
sequences as the science data, than with a single dark current
image
scaled by desired exposure time. Therefore, dark current images
must
be collected using all sample sequences that will be used in
science
observations. These observations will be used to monitor changes
in
the dark current of the WFC3-IR channel on a day-to-day basis, and to
build
calibration dark current ramps for each of the sample sequences to
be
used by GOs in Cycle 17. For each sample sequence/array size
combination,
a median ramp will be created and delivered to the
calibration
database system (CDBS).
WFC3/UVIS
11924
WFC3/UVIS
External and Internal CTE Monitor
CCD
detector Charge Transfer Inefficiency (CTI)-induced losses in
photometry
and astrometry will be measured using observations of the
rich
open cluster NGC6791 and with the EPER (Extended Pixel Edge
Response)
method using tungsten lamp flat field exposures. Although we
do
not expect to see CTE effects at the outset of Cycle 17, this CTE
monitoring
program is the first of a multi-cycle program to monitor and
establish
CTE-induced losses with time. We expect to measure CTE effects
with
a precision comparable to the ACS measurements.
WFC3/UVIS
11912
UVIS
Internal Flats
This
proposal will be used to assess the stability of the flat field
structure
for the UVIS detector throughout the 15 months of Cycle 17.
The
data will be used to generate on- orbit updates for the delta-flat
field
reference files used in the WFC3 calibration pipeline, if
significant
changes in the flat structure are seen.
WFC3/UVIS
11908
Cycle
17: UVIS Bowtie Monitor
Ground
testing revealed an intermittent hysteresis type effect in the
UVIS
detector (both CCDs) at the level of ~1%, lasting hours to days.
Initially
found via an unexpected bowtie-shaped feature in flatfield
ratios,
subsequent lab tests on similar e2v devices have since shown
that
it is also present as simply an overall offset across the entire
CCD,
i.e., a QE offset without any discernable pattern. These lab tests
have
further revealed that overexposing the detector to count levels
several
times full well fills the traps and effectively neutralizes the
bowtie.
Each visit in this proposal acquires a set of three 3x3 binned
internal
flatfields: the first unsaturated image will be used to detect
any
bowtie, the second, highly exposed image will neutralize the bowtie
if
it is present, and the final image will allow for verification that
the
bowtie is gone.
WFC3/UVIS
11907
UVIS
Cycle 17 Contamination Monitor
The
UV throughput of WFC3 during Cycle 17 is monitored via weekly
standard
star observations in a subset of key filters covering 200-600nm
and
F606W, F814W as controls on the red end. The data will provide a
measure
of throughput levels as a function of time and wavelength,
allowing
for detection of the presence of possible contaminants.
WFC3/UVIS
11905
WFC3
UVIS CCD Daily Monitor
The
behavior of the WFC3 UVIS CCD will be monitored daily with a set of
full-frame,
four-amp bias and dark frames. A smaller set of 2Kx4K
subarray
biases are acquired at less frequent intervals throughout the
cycle
to support subarray science observations. The internals from this
proposal,
along with those from the anneal procedure (Proposal 11909),
will
be used to generate the necessary superbias and superdark reference
files
for the calibration pipeline (CDBS).
ACS/WFC3
11879
CCD
Daily Monitor (Part 1)
This
program comprises basic tests for measuring the read noise and dark
current
of the ACS WFC and for tracking the growth of hot pixels. The
recorded
frames are used to create bias and dark reference images for
science
data reduction and calibration. This program will be executed
four
days per week (Mon, Wed, Fri, Sun) for the duration of Cycle 17. To
facilitate
scheduling, this program is split into three proposals. This
proposal
covers 352 orbits (22 weeks) from 31 August 2009 to 31 January
2010.
STIS/CCD/MA1/MA2
11860
MAMA
Spectroscopic Sensitivity and Focus Monitor
the
purpose of this proposal is to monitor the sensitivity of each MAMA
grating
mode to detect any change due to contamination or other causes,
and
to also monitor the STIS focus in a spectroscopic and an imaging
mode.
STIS/CCD
11852
STIS
CCD Spectroscopic Flats C17
The
purpose of this proposal is to obtain pixel-to-pixel lamp flat
fields
for the STIS CCD in spectroscopic mode.
STIS/CCD
11846
CCD
Bias Monitor-Part 1
The
purpose of this proposal is to monitor the bias in the 1x1, 1x2,
2x1,
and 2x2 bin settings at gain=1, and 1x1 at gain = 4, to build up
high-S/N
superbiases and track the evolution of hot columns.
STIS/CCD
11844
CCD
Dark Monitor Part 1
The
purpose of this proposal is to monitor the darks for the STIS CCD.
FGS
11790
HST/FGS
Astrometric Search for Young Planets Around Beta Pic and AU Mic
AU
Mic is a nearby Vega-type debris disk star. Its disk system has been
spatially
resolved in exquisite detail, predominantly via the ACS
coronagraph
and WFPC2 cameras onboard HST. These images exhibit a wealth
of
morphological features which provide compelling indirect evidence
that
AU Mic likely harbors short-period planetary body/bodies. We
propose
to use the superlative astrometric capabilities of HST/FGS to
directly
detect these planets, hence provide the first direct planet
detection
in a Vega- type system whose disk has been imaged at high
spatial
resolution.
FGS
11789
An
Astrometric Calibration of Population II Distance Indicators
In
2002, HST produced a highly precise parallax for RR Lyrae. That
measurement
resulted in an absolute magnitude, M(V)= 0.61+/-0.11, a
useful
result, judged by the over ten refereed citations each year
since.
It is, however, unsatisfactory to have the direct,
parallax-based,
distance scale of Population II variables based on a
single
star. We propose, therefore, to obtain the parallaxes of four
additional
RR Lyrae stars and two Population II Cepheids, or W Vir
stars.
The Population II Cepheids lie with the RR Lyrae stars on a
common
K-band Period-Luminosity relation. Using these parallaxes to
inform
that relationship, we anticipate a zero-point error of 0.04
magnitude.
This result should greatly strengthen confidence in the
Population
II distance scale and increase our understanding of RR Lyrae
star
and Pop. II Cepheid astrophysics.
FGS
11704
The
Ages of Globular Clusters and the Population II Distance Scale
Globular
clusters are the oldest objects in the universe whose age can
be
accurately determined. The dominant error in globular cluster age
determinations
is the uncertain Population II distance scale. We propose
to
use FGS 1R to obtain parallaxes with an accuracy of 0.2
milliarcsecond
for 9 main sequence stars with [Fe/H] < -1.5. This will
determine
the absolute magnitude of these stars with accuracies of 0.04
to
0.06mag. This data will be used to determine the distance to 24
metal-poor
globular clusters using main sequence fitting. These
distances
(with errors of 0.05 mag) will be used to determine the ages
of
globular clusters using the luminosity of the subgiant branch as an
age
indicator. This will yield absolute ages with an accuracy of 5%,
about
a factor of two improvement over current estimates. Coupled with
existing
parallaxes for more metal-rich stars, we will be able to
accurately
determine the age for globular clusters over a wide range of
metallicities
in order to study the early formation history of the Milky
Way
and provide an independent estimate of the age of the universe.
The
Hipparcos database contains only 1 star with [Fe/H] < -1.4 and an
absolute
magnitude error less than 0.18 mag which is suitable for use in
main
sequence fitting. Previous attempts at main sequence fitting to
metal-poor
globular clusters have had to rely on theoretical
calibrations
of the color of the main sequence. Our HST parallax program
will
remove this source of possible systematic error and yield distances
to
metal- poor globular clusters which are significantly more accurate
than
possible with the current parallax data. The HST parallax data will
have
errors which are 10 times smaller than the current parallax data.
Using
the HST parallaxes, we will obtain main sequence fitting distances
to
11 globular clusters which contain over 500 RR Lyrae stars. This will
allow
us to calibrate the absolute magnitude of RR Lyrae stars, a
commonly
used Population II distance indicator.
ACS/WFC3
11670
The
Host Environments of Type Ia Supernovae in the SDSS Survey
The
Sloan Digital Sky Survey Supernova Survey has discovered nearly 500
type
Ia supernovae and created a large, unique, and uniform sample of
these
cosmological tools. As part of a comprehensive study of the
supernova
hosts, we propose to obtain Hubble ACS images of a large
fraction
of these galaxies. Integrated colors and spectra will be
measured
from the ground, but we require high-resolution HST imaging to
provide
accurate morphologies and color information at the site of the
explosion.
This information is essential in determining the systematic
effects
of population age on type Ia supernova luminosities and
improving
their reliability in measuring dark energy. Recent studies
suggest
two populations of type Ia supernovae: a class that explodes
promptly
after star-formation and one that is delayed by billions of
years.
Measuring the star-formation rate at the site of the supernova
from
colors in the HST images may be the best way to differentiate
between
these classes.
WFC3/UVIS
11657
The
Population of Compact Planetary Nebulae in the Galactic Disk
We
propose to secure narrow- and broad-band images of compact planetary
nebulae
(PNe) in the Galactic Disk to study the missing link of the
early
phases of post-AGB evolution. Ejected AGB envelopes become PNe
when
the gas is ionized. PNe expand, and, when large enough, can be
studied
in detail from the ground. In the interim, only the HST
capabilities
can resolve their size, morphology, and central stars. Our
proposed
observations will be the basis for a systematic study of the
onset
of morphology. Dust properties of the proposed targets will be
available
through approved Spitzer/IRS spectra, and so will the
abundances
of the alpha-elements. We will be able thus to explore the
interconnection
of morphology, dust grains, stellar evolution, and
populations.
The target selection is suitable to explore the nebular and
stellar
properties across the Galactic Disk, and to set constraints on
the
galactic evolutionary models through the analysis of metallicity and
population
gradients.
STIS/MA1
11649
Elucidating
the Mystery of the Io Footprint Time Variations
The
Io UV footprint (IFP) is an auroral emission on Jupiter consisting
of
one or more spots resulting from the electromagnetic interaction
between
Io and the Jovian magnetosphere. Recent UV HST observations of
the
Jovian aurora raised new issues and put previous interpretations
under
question. Dedicated STIS Time-Tag observations based on only 3 HST
orbits
will help us to directly answer the following questions and test
new
hypothesis on the physics driving their associated phenomenon.
The
proposed observations will determine whether the previously observed
short
timescale (~2 min) variations of the IFP are periodic or burst
events.
If the (quasi-) periodicity is established, these constraints
will
help us to understand the origin of these variations. These
observations
will also clarify the conditions of occurrence of the
unexpected
quasi-simultaneous variations of the southern multiple spots
of
the IFP. Moreover, we propose to observe the emergence of the
southern
leading (or precursor) spot and the possible evolution of its
brightness.
These two elements might validate or exclude the recently
proposed
idea that cross-hemisphere electron beams or strong non-
linearities
of the electromagnetic interaction explain the presence of
the
leading and secondary spots.
ACS/WFC3
11599
Distances
of Planetary Nebulae from SNAPshots of Resolved Companions
REliable
distances to individual planetary nebulae (PNe) in the Milky
Way
are needed to advance our understanding of their spatial
distribution,
birthrates, influence on galactic chemistry, and the
luminosities
and evolutionary states of their central stars (CSPN). Few
PNe
have good distances, however. One of the best ways to remedy this
problem
is to find resolved physical companions to the CSPN and measure
their
distances by photometric main-sequence fitting. We have previously
used
HST to identify and measure probable companions to 10 CSPN, based
on
angular separations and statistical arguments only. We now propose to
use
HST to re-observe 48 PNe from that program for which additional
companions
are possibly present. We then can use the added criterion of
common
proper motion to confirm our original candidate companions and
identify
new ones in cases that could not confidently be studied before.
We
will image the region around each CSPN in the V and I bands, and in
some
cases in the B band. Field stars that appear close to the CSPN by
chance
will be revealed by their relative proper motion during the 13+
years
since our original survey, leaving only genuine physical
companions
in our improved and enlarged sample. This study will increase
the
number of Galactic PNe with reliable distances by 50 percent and
improve
the distances to PNe with previously known companions.
WFC3/UVIS
11588
Galaxy-Scale
Strong Lenses from the CFHTLS Survey
We
aim to investigate the origin and evolution of early-type galaxies
using
gravitational lensing, modeling the mass profiles of objects over
a
wide range of redshifts. The low redshift (z = 0.2) sample is already
in
place following the successful HST SLACS survey; we now propose to
build
up and analyze a sample of comparable size (~50 systems) at high
redshift
(0.4 < z < 0.9) using HST WFC3 Snapshot observations of lens
systems
identified by the SL2S collaboration in the CFHT legacy survey.
WFC3/UVIS
11565
A
Search for Astrometric Companions to Very Low-Mass, Population II
Stars
We
propose to carry out a Snapshot search for astrometric companions in
a
subsample of very low-mass, halo subdwarfs identified within 120
parsecs
of the Sun. These ultra-cool M subdwarfs are local
representatives
of the lowest-mass H burning objects from the Galactic
Population
II. The expected 3-4 astrometric doubles that will be
discovered
will be invaluable in that they will be the first systems
from
which gravitational masses of metal-poor stars at the bottom of the
main
sequence can be directly measured.
COS/FUV
11482
FUV
Detector Dark
Measure
the FUV detector dark rate by taking long science exposures with
no
light on the detector. The detector dark rate and spatial
distribution
of counts will be compared to pre-launch data in order to
verify
the nominal operation of the detector, and for use in the CalCOS
calibration
pipeline. Variations of count rate as a function of orbital
position
will be analyzed to find dependence of dark rate on proximity
to
the SAA.
This
is SMOV Activity COS-24.
COS/NUV
11473
COS
NUV Imaging Performance Verification
This
activity is designed to verify the performance of the COS/NUV
imaging
mode. In particular, the PSF quality will be assessed and the
plate
scale will be measured. The throughput of the Mirror A with both
the
PSA and BOA will be fully calibrated by observing an appropriate HST
flux
standard star, and will be characterized as a function of location
within
the aperture by moving the star from the center to various
positions
with a grid pattern. The relative throughput of Mirror A vs.
Mirror
B will also be evaluated in the center of both the PSA and BOA.
This
activity will be structured in a way that will also allow for
testing
of the drift following the OSM motion in imaging mode and for
testing
of the image stability within an orbit and over several orbits.
WFC3/UVIS
11432
UVIS
Internal Flats
This
proposal will be used to assess the stability of the flat field
structure
for the UVIS detector. Flat fields will be obtained for all
filters
using the internal D2 and tungsten lamps.
This
proposal corresponds to Activity Description ID WF19. It should
execute
only after the following proposals have executed:
WF08
- Proposal 11421
WF09
- Proposal 11422
WF11
- Proposal 11424
WF15
- Proposal 11428
WFC3/IR
11208
The
Co-Evolution of Spheroids and Black Holes in the Last Six Billion
Years
The
masses of giant black holes are correlated with the luminosities,
masses,
and velocity dispersions of the bulges of their host galaxies.
This
empirical correlation of phenomena on widely different scales (from
pcs
to kpcs) suggests that the formation and evolution of galaxies and
central
black holes are closely linked. In Cycle 13, we have started a
campaign
to map directly the co-evolution of spheroids and black-holes
by
measuring in observationally favorable redshift windows the empirical
correlations
connecting their properties. By focusing on Seyfert 1s,
where
the nucleus and the stars contribute comparable fractions of total
light,
black hole mass and bulge dispersion are obtained from Keck
spectroscopy.
HST is required for accurate measurement of the non-
stellar
AGN continuum, the morphology of the galaxy, and the structural
parameters
of the bulge. The results at z=0.36 indicate a surprisingly
fast
evolution of bulges in the past 4 Gyrs (significant at the 95%CL),
in
the sense that bulges were significantly smaller for a given black
hole
mass. Also, the large fraction of mergers and disturbed galaxies
(4+2
out of 20) identifies gas-rich mergers as the mechanisms
responsible
for bulge- growth. Going to higher redshift - where
evolutionary
trends should be stronger - is needed to confirm these
tantalizing
results. We propose therefore to push our investigation to
the
next suitable redshift window z=0.57 (lookback-time 6 Gyrs). Fifteen
objects
are the minimum number required to map the evolution of the
empirical
correlations between bulge properties and black-hole mass, and
to
achieve a conclusive detection of evolution (>99%CL).
WFC3/IR
11202
The
Structure of Early-type Galaxies: 0.1-100 Effective Radii
The
structure, formation and evolution of early-type galaxies is still
largely
an open problem in cosmology: how does the Universe evolve from
large
linear scales dominated by dark matter to the highly non-linear
scales
of galaxies, where baryons and dark matter both play important,
interacting,
roles? To understand the complex physical processes
involved
in their formation scenario, and why they have the tight
scaling
relations that we observe today (e.g. the Fundamental Plane), it
is
critically important not only to understand their stellar structure,
but
also their dark-matter distribution from the smallest to the largest
scales.
Over the last three years the SLACS collaboration has developed
a
toolbox to tackle these issues in a unique and encompassing way by
combining
new non-parametric strong lensing techniques, stellar
dynamics,
and most recently weak gravitational lensing, with
high-quality
Hubble Space Telescope imaging and VLT/Keck spectroscopic
data
of early-type lens systems. This allows us to break degeneracies
that
are inherent to each of these techniques separately and probe the
mass
structure of early-type galaxies from 0.1 to 100 effective radii.
The
large dynamic range to which lensing is sensitive allows us both to
probe
the clumpy substructure of these galaxies, as well as their
low-density
outer haloes. These methods have convincingly been
demonstrated,
by our team, using smaller pilot-samples of SLACS lens
systems
with HST data. In this proposal, we request observing time with
WFC3
and NICMOS to observe 53 strong lens systems from SLACS, to obtain
complete
multi-color imaging for each system. This would bring the total
number
of SLACS lens systems to 87 with completed HST imaging and
effectively
doubles the known number of galaxy- scale strong lenses. The
deep
HST images enable us to fully exploit our new techniques, beat down
low-number
statistics, and probe the structure and evolution of
early-type
galaxies, not only with a uniform data-set an order of
magnitude
larger than what is available now, but also with a
fully-coherent
and self-consistent methodological approach!
FLIGHT
OPERATIONS SUMMARY:
Significant
Spacecraft Anomalies: (The following are preliminary reports
of
potential non-nominal performance that will be investigated.)
HSTARS:
12013
- REAcq(2,3,3) scheduled at 255/06:42:04z - 06:46:30z was observed
to have failed to RGA Hold (gyro control) due to search radius
limit
exceeded on FGS-2.
Observations affected: STIS 74 - 76, Proposal ID# 11860
COMPLETED
OPS REQUEST:
18700-0
- Null genslew for proposal 11492 - slot 1 @ 254/19:30z
COMPLETED
OPS NOTES: (None)
SCHEDULED
SUCCESSFUL
FGS
GSAcq
37
37
FGS
REAcq
11
10
OBAD
with Maneuver
24
24
SIGNIFICANT
EVENTS: (None)