Notice: Due to the conversion of some ACS WFC or HRC
observations into
WFPC2, or NICMOS observations after the loss of ACS CCD
science
capability in January, there may be an occasional
discrepancy between a
proposal's listed (and correct) instrument usage and the
abstract that
follows it.
HUBBLE SPACE TELESCOPE - Continuing to collect World Class
Science
DAILY REPORT # 4402
PERIOD COVERED: UT July 11, 2007 (DOY 192)
OBSERVATIONS SCHEDULED
FGS 11210
The Architecture of Exoplanetary Systems
Are all planetary systems coplanar? Concordance cosmogony
makes that
prediction. It is, however, a prediction of extrasolar
planetary system
architecture as yet untested by direct observation for
main sequence
stars other than the Sun. To provide such a test, we
propose to carry
out FGS astrometric studies on four stars hosting seven
companions. Our
understanding of the planet formation process will grow as
we match not
only system architecture, but formed planet mass and true
distance from
the primary with host star characteristics for a wide
variety of host
stars and exoplanet masses. We propose that a series of
FGS astrometric
observations with demonstrated 1 millisecond of arc
per-observation
precision can establish the degree of coplanarity and
component true
masses for four extrasolar systems: HD 202206 {brown
dwarf+planet}; HD
128311 {planet+planet}, HD 160691 = mu Arae
{planet+planet}, and HD
222404AB = gamma Cephei {planet+star}. In each case the
companion is
identified as such by assuming that the minimum mass is
the actual mass.
For the last target, a known stellar binary system, the
companion orbit
is stable only if coplanar with the AB binary orbit.
FGS 11211
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
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.
NIC1/NIC2/NIC3 8793
NICMOS Post-SAA calibration - CR Persistence Part 4
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.
NIC2 10893
Sweeping Away the Dust: Reliable Dark Energy with an
Infrared Hubble
Diagram
We propose building a high-z Hubble Diagram using type Ia
supernovae
observed in the infrared rest-frame J-band. The infrared
has a number of
exceptional properties. The effect of dust extinction is
minimal,
reducing a major systematic tha may be biasing dark energy
measurements.
Also, recent work indicates that type Ia supernovae are
true standard
candles in the infrared meaning that our Hubble diagram
will be
resistant to possible evolution in the Phillips relation
over cosmic
time. High signal-to-noise measurements of 9 type Ia
events at z~0.4
will be compared with an independent optical Hubble
diagram from the
ESSENCE project to test for a shift in the derived dark
energy equation
of state due to a systematic bias. Because of the bright
sky background,
H-band photometry of z~0.4 supernovae is not feasible from
the ground.
Only the superb image quality and dark infrared sky seen
by HST makes
this test possible. This experiment may also lead to a
better, more
reliable way of mapping the expansion history of the
universe with the
Joint Dark Energy
WFPC2 10818
Very Young Globular Clusters in M31 ?
We propose to use HST's unique high spatial resolution
imaging
capabilities to conclusively confirm or refute the
presence of alleged
very young globular clusters in M31. Such young globular
clusters with
ages < 3 Gyr are not present in our galaxy, and, if
real, would lead to
a striking difference in the age distribution of the GCs
between M31 and
the
in M31 is confirmed through our proposed ACS imaging {now
WFPC2 imaging}
with HST, this would suggest major differences in the
history of
assembly of the two galaxies, with probable substantial
late accretion
into M31 which did not occur in our own galaxy.
WFPC2 11029
WFPC2 CYCLE 15 Intflat Linearity Check and Filter Rotation
Anomaly
Monitor
Intflat observations will be taken to provide a linearity
check: the
linearity test consists of a series of intflats in F555W,
in each gain
and each shutter. A combination of intflats, visflats, and
earthflats
will be used to check the repeatability of filter wheel
motions.
{Intflat sequences tied to decons, visits 1-18 in prop
10363, have been
moved to the cycle 15 decon proposal xxxx for easier
scheduling.} Note:
long-exposure WFPC2 intflats must be scheduled during ACS
anneals to
prevent stray light from the WFPC2 lamps from
contaminating long ACS
external exposures.
WFPC2 11079
Treasury Imaging of Star Forming Regions in the Local
Group:
Complementing the GALEX and NOAO Surveys
We propose to use WFPC2 to image the most interesting
star-forming
regions in the Local Group galaxies, to resolve their
young stellar
populations. We will use a set of filters including F170W,
which is
critical to detect and characterize the most massive
stars, to whose hot
temperatures colors at longer wavelengths are not sensitive.
WFPC2's
field of view ideally matches the typical size of the
star-forming
regions, and its spatial resolution allows us to measure
indvidual
stars, given the proximity of these galaxies. The
resulting H-R diagrams
will enable studies of star- formation properties in these
regions,
which cover largely differing metallicities {a factor of
17, compared to
the factor of 4 explored so far} and characteristics. The
results will
further our understanding of the star-formation process,
of the
interplay between massive stars and environment, the
properties of dust,
and will provide the key to interpret integrated
measurements of
star-formation indicators {UV, IR, Halpha} available for
several
hundreds more distant galaxies. Our recent deep surveys of
these
galaxies with GALEX {FUV, NUV} and ground-based imaging
{UBVRI, Halpha,
[OIII] and [SII]} provided the identification of the most
relevant SF
sites. In addition to our scientific analysis, we will
provide catalogs
of HST photometry in 6 bands, matched corollary
ground-based data, and
UV, Halpha and IR integrated measurements of the
associations, for
comparison of integrated star-formation indices to the
resolved
populations. We envisage an EPO component.
WFPC2 11175
UV Imaging to Determine the Location of Residual Star
Formation in
Galaxies Recently Arrived on the Red Sequence
We have indentified a sample of low-redshift {z = 0.04 -
0.10} galaxies
that are candidates for recent arrival on the red
sequence. They have
red optical colors indicative of old stellar populations,
but blue
UV-optical colors that could indicate the presence of a
small quantity
of continuing or very recent star formation. However,
their spectra lack
the emission lines that characterize star-forming
galaxies. We propose
to use ACS/SBC to obtain high-resolution imaging of the UV
flux in these
galaxies, in order to determine the spatial distribution
of the last
episode of star formation. WFPC2 imaging will provide B,
V, and I
photometry to measure the main stellar light distribution
of the galaxy
for comparison with the UV imaging, as well as to measure
color
gradients and the distribution of interstellar dust. This
detailed
morphological information will allow us to investigate the
hypothesis
that these galaxies have recently stopped forming stars
and to compare
the observed distribution of the last star formation with
predictions
for several different mechanisms that may quench star
formation in
galaxies.
WFPC2 11178
Probing Solar System History with Orbits, Masses, and
Colors of
Transneptunian Binaries
The recent discovery of numerous transneptunian binaries
{TNBs} opens a
window into dynamical conditions in the protoplanetary
disk where they
formed as well as the history of subsequent events which sculpted
the
outer Solar System and emplaced them onto their present
day heliocentric
orbits. To date, at least 47 TNBs have been discovered,
but only about a
dozen have had their mutual orbits and separate colors
determined,
frustrating their use to investigate numerous important
scientific
questions. The current shortage of data especially
cripples scientific
investigations requiring statistical comparisons among the
ensemble
characteristics. We propose to obtain sufficient
astrometry and
photometry of 23 TNBs to compute their mutual orbits and
system masses
and to determine separate primary and secondary colors,
roughly tripling
the sample for which this information is known, as well as
extending it
to include systems of two near-equal size bodies. To make
the most
efficient possible use of HST, we will use a
optimally schedule our observations.
FLIGHT OPERATIONS SUMMARY:
Significant Spacecraft Anomalies: (The following are
preliminary reports
of potential non-nominal performance that will be
investigated.)
HSTARS: #10888 GSAcq(2,0,2) failed to RGA Hold (Gyro
Control) Upon
acquisition of signal (AOS) at 192/11:43:01, the
GSAcq(2,0,2) scheduled
at 192/10:55:18 - 11:01:35 had failed to RGA Hold due to
(QF2STOPF) stop
flag indication on FGS-2. Scheduled Astrometry FGS1 did
not attempt.
Pre-acquisition OBADs attitude correction values not
available due to
LOS. Post-acq OBAD/MAP had (RSS) value of 15.71
arcseconds.
#10889 REAcq (1,2,1) failed due to Search Radius Limit Exceeded
on FGS 1
At 192/20:54:28 REAcq (1,2,1) scheduled from
20:49:36-20:57:04 had
failed due to search radius limit exceeded on FGS 1. At
20:48:31 F2SOB
(FHST2 Stuck on Bottom) showed OOL. Unable to execute Ops
Request
17597-9 due to forward not available. OBAD #1: V1 -29.22,
V2 2604.20, V3
0.32, RSS 2604.36 OBAD #2: V1 -3.09, V2 -14.18, V3 172.41,
RSS 173.02
OBAD MAP: V1 3.34, V2 4.95, V3 -151.58, RSS 151.70
#10890 GSAcq (1,2,1) failed due to Search Radius Limit
Exceeded on FGS 1
At AOS 192/22:47:30 observed that GSAcq (1,2,1)scheduled
from
22:30:10-22:37:22 had failed due to search radius limit
exceeded on FGS
1. OBAD data unavailable until next scheduled engineering
dump. OBAD
MAP: v1 -78.32, V2 26.00, V3 -145.71, RSS 167.46
At AOS 193/00:03:45 REAcq (1,2,1) scheduled from
00:03:46-00:10:58
failed due to search radius limit exceeded on FGS 1. OBAD
data
unavailable due to LOS. Awaiting next scheduled
engineering dump. OBAD
MAP RSS: V1 4.74, V2 -8.31, V3 -63.96, RSS 64.67
COMPLETED OPS REQUEST: (None)
SCHEDULED
SUCCESSFUL
FGS
GSacq
8
6
FGS
REacq
6
4
OBAD with Maneuver
28
28
COMPLETED OPS NOTES: (None)
SIGNIFICANT EVENTS: (None)