Daily Report #4402

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 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.

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 Mission.

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 Millky Way. If the apparent presence of very young
globular clusters 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 Monte Carlo technique to 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)