HUBBLE
SPACE TELESCOPE - Continuing to Collect World Class Science
DAILY
REPORT #5070
PERIOD
COVERED: 5am April 7 - 5am April 8, 2010 (DOY 097/09:00z-098/09:00z)
OBSERVATIONS
SCHEDULED
ACS/WFC
11995
CCD
Daily Monitor (Part 2)
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 320 orbits (20 weeks) from 1 February 2010 to 20 June
2010.
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.
STIS/CC
11654
UV
Studies of a Core Collapse Supernova
Observations
of the UV spectrum of core collapse SNe hold unique
information
about nucleosynthesis, the mass loss history, shock physics
and
dust formation in the explosion on massive stars. This proposal aims
at
a detailed study of a bright core collapse SN, discovered by any of
the
many ongoing surveys, either a Type IIP, IIn or Ibc supernova. We
will
address the role of circumstellar interaction and mass loss through
CNO
lines in the UV, the nature of dust formation from UV line profiles
and
use the UV continuum as a diagnostic of non-thermal emission from
the
shock. The overall goal of our team is to achieve a better
understanding
of these objects by combining HST data with complementary
ground-based
observations. We have used HST to obtain UV spectra from
the
explosion to the nebular phase. Over the past decade, we have
conducted
studies of nearby SNe with HST, and we have published an
extensive
series of papers. When Nature provides a bright candidate, HST
should
be ready to respond.
STIS/CC
11845
CCD
Dark Monitor Part 2
Monitor
the darks for the STIS CCD.
STIS/CC
11847
CCD
Bias Monitor-Part 2
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
11784
The
Orbit of the Most Massive Known Astrometric Binary
We
have recently used FGS and HRC observations to (a) resolve HD 93129A
into
two components with very similar optical/UV colors and a magnitude
difference
of 0.9 and to (b) detect their relative orbital motion over a
span
of 8 years. HD 93129Aa is the prototype O2 If* star, with an
evolutionary
mass near 100 M_Sun, while Ab is likely to be a very early
O
main-sequence star with a similar or only slightly smaller mass. Our
HST
astrometric measurements yield a total mass above 100 M_Sun, thus
confirming
the extremely high mass of the binary, and indicate that the
system
appears to be approaching periastron. We request new FGS and HRC
observations
to (a) calculate the mass ratio of the system by measuring
the
orbit of each of the components with respect to the nearby stars,
(b)
obtain the periastron epoch, and (c) start measuring the orbit in
order
to produce an estimate of the total mass. These measurements are
crucial
to shed light on the value of the stellar upper mass limit. Due
the
the non-recovery of HRC on SM4, the last visit was changed to STIS.
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/MA2
11568
A
SNAPSHOT Survey of the Local Interstellar Medium: New NUV Observations
of
Stars with Archived FUV Observations
We
propose to obtain high-resolution STIS E230H SNAP observations of
MgII
and FeII interstellar absorption lines toward stars within 100
parsecs
that already have moderate or high-resolution far-UV (FUV),
900-1700
A, observations available in the MAST Archive. Fundamental
properties,
such as temperature, turbulence, ionization, abundances, and
depletions
of gas in the local interstellar medium (LISM) can be
measured
by coupling such observations. Due to the wide spectral range
of
STIS, observations to study nearby stars also contain important data
about
the LISM embedded within their spectra. However, unlocking this
information
from the intrinsically broad and often saturated FUV
absorption
lines of low-mass ions, (DI, CII, NI, OI), requires first
understanding
the kinematic structure of the gas along the line of
sight.
This can be achieved with high resolution spectra of high-mass
ions,
(FeII, MgII), which have narrow absorption lines, and can resolve
each
individual velocity component (interstellar cloud). By obtaining
short
(~10 minute) E230H observations of FeII and MgII, for stars that
already
have moderate or high- resolution FUV spectra, we can increase
the
sample of LISM measurements, and thereby expand our knowledge of the
physical
properties of the gas in our galactic neighborhood. STIS is the
only
instrument capable of obtaining the required high resolution data
now
or in the foreseeable future.
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/UV
11635
Improve
the Measurement of Vesta's Pole Orientation to Support Dawn
Mission
NASA's
Dawn spacecraft is scheduled to go into orbit around the main
belt
asteroid 4 Vesta in July 2011. Currently the project is using a 3-
pole
position uncertainty of Vesta of 12 for spacecraft trajectory
design.
We have determined that with an additional set of Hubble
observations
at Vesta's next opposition in February 2010, that the pole
position
uncertainty can be reduced by a factor of 4. This will reduce
both
cost and risk to the Dawn mission, and is likely to increase the
stay
time at Vesta and will add to the scientific return of the mission.
The
requested observing window in February 2010 is the last and single
best
opportunity that can benefit the Dawn mission, but it is before the
start
of the next HST Cycle.
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).
WFC3/UVIS/IR
11644
A
Dynamical-Compositional Survey of the Kuiper Belt: A New Window Into
the
Formation of the Outer Solar System
The
eight planets overwhelmingly dominate the solar system by mass, but
their
small numbers, coupled with their stochastic pasts, make it
impossible
to construct a unique formation history from the dynamical or
compositional
characteristics of them alone. In contrast, the huge
numbers
of small bodies scattered throughout and even beyond the
planets,
while insignificant by mass, provide an almost unlimited number
of
probes of the statistical conditions, history, and interactions in
the
solar system. To date, attempts to understand the formation and
evolution
of the Kuiper Belt have largely been dynamical simulations
where
a hypothesized starting condition is evolved under the
gravitational
influence of the early giant planets and an attempt is
made
to reproduce the current observed populations. With little
compositional
information known for the real Kuiper Belt, the test
particles
in the simulation are free to have any formation location and
history
as long as they end at the correct point. Allowing compositional
information
to guide and constrain the formation, thermal, and
collisional
histories of these objects would add an entire new dimension
to
our understanding of the evolution of the outer solar system. While
ground
based compositional studies have hit their flux limits already
with
only a few objects sampled, we propose to exploit the new
capabilities
of WFC3 to perform the first ever large-scale
dynamical-compositional
study of Kuiper Belt Objects (KBOs) and their
progeny
to study the chemical, dynamical, and collisional history of the
region
of the giant planets. The sensitivity of the WFC3 observations
will
allow us to go up to two magnitudes deeper than our ground based
studies,
allowing us the capability of optimally selecting a target list
for
a large survey rather than simply taking the few objects that can be
measured,
as we have had to do to date. We have carefully constructed a
sample
of 120 objects which provides both overall breadth, for a general
understanding
of these objects, plus a large enough number of objects in
the
individual dynamical subclass to allow detailed comparison between
and
within these groups. These objects will likely define the core
Kuiper
Belt compositional sample for years to come. While we have many
specific
results anticipated to come from this survey, as with any
project
where the field is rich, our current knowledge level is low, and
a
new instrument suddenly appears which can exploit vastly larger
segments
of the population, the potential for discovery -- both
anticipated
and not -- is extraordinary.
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
7
7
FGS
REAcq
9
9
OBAD
with Maneuver 6
6
SIGNIFICANT
EVENTS: (None)