HUBBLE
SPACE TELESCOPE - Continuing to Collect World Class Science
DAILY
REPORT #5136
PERIOD
COVERED: 5am July 12 - 5am July 13, 2010 (DOY 193/09:00z-194/09:00z)
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
9
9
FGS
REAcq
7
7
OBAD
with Maneuver 8
8
SIGNIFICANT
EVENTS: (None)
OBSERVATIONS
SCHEDULED:
ACS/WFC
11996
CCD
Daily Monitor (Part 3)
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 308 orbits (19.25 weeks) from 21 June 2010 to 1 November
2010.
COS/FUV
11699
On
the Evolutionary Status of Extremely Hot Helium Stars - are the O(He)
Stars
Successors of the R CrB Stars?
We
propose UV spectroscopy of the four unique post-AGB stars of spectral
type
O(He) in order to understand the origin of their peculiar surface
abundances.
These stars are the only known amongst the hottest post-AGB
stars
(effective temperatures > 100, 000 K) whose atmospheres are
composed
of almost pure helium. This chemistry markedly differs from
that
of the hydrogen-deficient post-AGB evolutionary sequence with
objects
which have carbon dominated atmospheres (PG1159 stars and
Wolf-Rayet
central stars).
While
PG1159 and Wolf-Rayet stars are the result of a late helium-shell
flash,
this scenario cannot explain the O(He) stars. Instead, they are
possibly
double-degenerate mergers. We speculate that the four O(He)
stars
represent evolved RCrB stars, which also have helium-dominated
atmospheres.
We aim to determine the C, N, O, and Si abundances
precisely,
in order to proof this evolutionary link.
COS/FUV
11895
FUV
Detector Dark Monitor
Monitor
the FUV detector dark rate by taking long science exposures
without
illuminating the detector. The detector dark rate and spatial
distribution
of counts will be compared to pre-launch and SMOV data in
order
to verify the nominal operation of the detector. Variations of
count
rate as a function of orbital position will be analyzed to find
dependence
of dark rate on proximity to the SAA. Dependence of dark rate
as
function of time will also be tracked.
COS/NUV
11894
NUV
Detector Dark Monitor
The
purpose of this proposal is to measure the NUV 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 and SMOV data in order to verify the nominal operation of
the
detector. Variations of count rate as a function of orbital position
will
be analyzed to find dependence of dark rate on proximity to the
SAA.
Dependence of dark rate as function of time will also be tracked.
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/CC/MA
11576
Physical
Parameters of the Upper Atmosphere of the Extrasolar Planet
HD209458b
One
of the most studied extrasolar planet, HD209458b, has revealed both
its
lower and upper atmosphere thanks to HST and Spitzer observatories.
Through
transmission spectroscopy technique, several atmospheric species
were
detected: NaI, HI, OI and CII. Using STIS archived transit
absorption
spectrum from 3000 to 8000 Angstrom, we obtained detailed
constraints
on the vertical profile of temperature, pressure and
abundances
(Sing et al 2008a, 2008b, Lecavelier et al. 2008b).
By
observing in the NUV, from 2300 to 3100 Angstrom, we expect to obtain
new
constraints on the physical conditions and the chemical composition
of
the upper atmosphere: temperature/pressure profile up to very high in
the
atmosphere, abundance and condensation altitudes of new species, and
new
insight in the atmospheric escape and ionization state at the upper
levels.
The observation of four HD209458b transits with a single E230M
setting
will give access to many NUV atomic lines addressing these
issues.
The proposed observations will probe, for the first time, in
details
the atmosphere of a hot Jupiter, thus bench marking follow up
studies.
STIS/CCD
11849
STIS
CCD Hot Pixel Annealing
This
purpose of this activity is to repair radiation induced hot pixel
damage
to the STIS CCD by warming the CCD to the ambient instrument
temperature
and annealing radiation-damaged pixels.
Radiation
damage creates hot pixels in the STIS CCD Detector. Many of
these
hot pixels can be repaired by warming the CCD from its normal
operating
temperature near -83 deg. C to the ambient instrument
temperature
(~ +5 deg. C) for several hours. The number of hot pixels
repaired
is a function of annealing temperature. The effectiveness of
the
CCD hot pixel annealing process is assessed by measuring the dark
current
behavior before and after annealing and by searching for any
window
contamination effects.
STIS/CCD
11853
Cycle
17 STIS CCD Imaging Flats
This
program periodically monitors the STIS CCD imaging mode flat fields
by
using the tungsten lamps.
WFC3/IR
11631
Binary
Brown Dwarfs and the L/T Transition
Brown
dwarfs traverse spectral types M, L and T as their atmospheric
structure
evolves and they cool into oblivion. This SNAPSHOT program
will
obtain WFC3-IR images of 45 nearby late-L and early-T dwarfs to
investigate
the nature of the L/T transition. Recent analyses have
suggested
that a substantial proportion of late-L and early-T dwarfs are
binaries,
comprised of an L dwarf primary and T dwarf secondary. WFC3-IR
observations
will let us quantify this suggestion by expanding coverage
to
a much larger sample, and permitting comparison of the L/T binary
fraction
against ‘normal’ ultracool dwarfs. Only eight L/T binaries are
currently
known, including several that are poorly resolved: we
anticipate
at least doubling the number of resolved systems. The
photometric
characteristics of additional resolved systems will be
crucial
to constraining theoretical models of these late-type ultracool
dwarfs.
Finally, our data will also be eminently suited to searching for
extremely
low luminosity companions, potentially even reaching the Y
dwarf
regime.
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/ACS/WFC/IR
12057
A
Panchromatic Hubble Andromeda Treasury - I
We
propose to image the north east quadrant of M31 to deep limits in the
UV,
optical, and near-IR. HST imaging should resolve the galaxy into
more
than 100 million stars, all with common distances and foreground
extinctions.
UV through NIR stellar photometry (F275W, F336W with
WFC3/UVIS,
F475W and F814W with ACS/WFC, and F110W and F160W with
WFC3/NIR)
will provide effective temperatures for a wide range of
spectral
types, while simultaneously mapping M31's extinction. Our
central
science drivers are to: understand high-mass variations in the
stellar
IMF as a function of SFR intensity and metallicity; capture the
spatially-resolved
star formation history of M31; study a vast sample of
stellar
clusters with a range of ages and metallicities. These are
central
to understanding stellar evolution and clustered star formation;
constraining
ISM energetics; and understanding the counterparts and
environments
of transient objects (novae, SNe, variable stars, x-ray
sources,
etc.). As its legacy, this survey adds M31 to the Milky Way and
Magellanic
Clouds as a fundamental calibrator of stellar evolution and
star-formation
processes for understanding the stellar populations of
distant
galaxies. Effective exposure times are 977s in F275W, 1368s in
F336W,
4040s in F475W, 4042s in F814W, 699s in F110W, and 1796s in
F160W,
including short exposures to avoid saturation of bright sources.
These
depths will produce photon-limited images in the UV. Images will
be
crowding-limited in the optical and NIR, but will reach below the red
clump
at all radii. The images will reach the Nyquist sampling limit in
F160W,
F475W, and F814W.
WFC3/UVIS
11595
Turning
Out the Light: A WFC3 Program to Image z>2 Damped Lyman Alpha
Systems
We
propose to directly image the star-forming regions of z>2 damped Lya
systems
(DLAs) using the WFC3/UVIS camera on the Hubble Space Telescope.
In
contrast to all previous attempts to detect the galaxies giving rise
to
high redshift DLAs, we will use a novel technique that completely
removes
the glare of the background quasar. Specifically, we will target
quasar
sightlines with multiple DLAs and use the higher redshift DLA as
a
``blocking filter'' (via Lyman limit absorption) to eliminate all FUV
emission
from the quasar. This will allow us to carry out a deep search
for
FUV emission from the lower redshift DLA, shortward of the Lyman
limit
of the higher redshift absorber. The unique filter set and high
spatial
resolution afforded by WFC3/UVIS will then enable us to directly
image
the lower redshift DLA and thus estimate its size, star- formation
rate
and impact parameter from the QSO sightline. We propose to observe
a
sample of 20 sightlines, selected primarily from the SDSS database,
requiring
a total of 40 HST orbits. The observations will allow us to
determine
the first FUV luminosity function of high redshift DLA
galaxies
and to correlate the DLA galaxy properties with the ISM
characteristics
inferred from standard absorption-line analysis to
significantly
improve our understanding of the general DLA population.
WFC3/UVIS
11697
Proper
Motion Survey of Classical and SDSS Local Group Dwarf Galaxies
Using
the superior resolution of HST, we propose to continue our proper
motion
survey of Galactic dwarf galaxies. The target galaxies include
one
classical dwarf, Leo II, and six that were recently identified in
the
Sloan Digital Sky Survey data: Bootes I, Canes Venatici I, Canes
Venatici
II, Coma Berenices, Leo IV, and Ursa Major II. We will observe
a
total of 16 fields, each centered on a spectroscopically-confirmed
QSO.
Using QSOs as standards of rest in measuring absolute proper
motions
has proven to be the most accurate and most efficient method.
HST
is our only option to quickly determine the space motions of the
SDSS
dwarfs because suitable ground-based imaging is only a few years
old
and such data need several decades to produce a proper motion. The
two
most distant galaxies in our sample will require time baselines of
four
years to achieve our goal of a 30-50 km/s uncertainty in the
tangential
velocity; given this and the finite lifetime of HST, it is
imperative
that first-epoch observations be taken in this cycle. The
SDSS
dwarfs have dramatically lower surface brightnesses and
luminosities
than the classical dwarfs. Proper motions are crucial for
determining
orbits of the galaxies and knowing the orbits will allow us
to
test theories for the formation and evolution of these galaxies and,
more
generally, for the formation of the Local Group.
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).