Daily Report #4621

HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

DAILY REPORT***** # 4621

PERIOD COVERED: 5am May 29 - 5am May 30, 2008 (DOY
150/0900z-151/0900z)

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 11212

Filling the Period Gap for Massive Binaries

The current census of binaries among the massive O-type stars is
seriously incomplete for systems in the period range from years to
millennia because the radial velocity variations are too small and the
angular separations too close for easy detection. Here we propose to
discover binaries in this observational gap through a Faint Guidance
Sensor SNAP survey of relatively bright targets listed in the Galactic
O Star Catalog. Our primary goal is to determine the binary frequency
among those in the cluster/association, field, and runaway groups. The
results will help us assess the role of binaries in massive star
formation and in the processes that lead to the ejection of massive
stars from their natal clusters. The program will also lead to the
identification of new, close binaries that will be targets of long
term spectroscopic and high angular resolution observations to
determine their masses and distances. The results will also be
important for the interpretation of the spectra of suspected and newly
identified binary and multiple systems.

NIC1/NIC2/NIC3 8795

NICMOS Post-SAA calibration - CR Persistence Part 6

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.

NIC3 11120

A Paschen-Alpha Study of Massive Stars and the ISM in the Galactic
Center

The Galactic center (GC) is a unique site for a detailed study of a
multitude of complex astrophysical phenomena, which may be common to
nuclear regions of many galaxies. Observable at resolutions
unapproachable in other galaxies, the GC provides an unparalleled
opportunity to improve our understanding of the interrelationships of
massive stars, young stellar clusters, warm and hot ionized gases,
molecular clouds, large scale magnetic fields, and black holes. We
propose the first large-scale hydrogen Paschen alpha line survey of
the GC using NICMOS on the Hubble Space Telescope. This survey will
lead to a high resolution and high sensitivity map of the Paschen
alpha line emission in addition to a map of foreground extinction,
made by comparing Paschen alpha to radio emission. This survey of the
inner 75 pc of the Galaxy will provide an unprecedented and complete
search for sites of massive star formation. In particular, we will be
able to (1) uncover the distribution of young massive stars in this
region, (2) locate the surfaces of adjacent molecular clouds, (3)
determine important physical parameters of the ionized gas, (4)
identify compact and ultra-compact HII regions throughout the GC. When
combined with existing Chandra and Spitzer surveys as well as a wealth
of other multi-wavelength observations, the results will allow us to
address such questions as where and how massive stars form, how
stellar clusters are disrupted, how massive stars shape and heat the
surrounding medium, and how various phases of this medium are
interspersed.

NIC3 11333

NICMOS non-linearity tests

This program incorporates a number of tests to analyze the count rate
dependent non-linearity seen in NICMOS spectro-photometric observations.

We will observe a field with stars of a range in luminosity in NGC3603
with NICMOS in NIC1: F090M, F110W, F140W, F160W NIC2: F110W, F160W,
F187W, F205W, and F222M NIC3: F110W, F150W, F160W, F175W, and F222M.
We will repeat the observations with flatfield lamp on, creating
artificially high count-rates, allowing tests of NICMOS linearity as
function of count rate. We first take exposures with the lamp off,
then exposures with the lamp on, and repeat at the end with lamp off.
Finally, we continue with taking darks during occultation.

We will furthermore observe spectro-photometric standard P041C using
the G096, G141, and G206 grisms in NIC3, and repeat the lamp
off/on/off test to artificially create a high background.

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.

WFPC2 11227

The orbital period for an ultraluminous X-ray source in NGC1313

The ultraluminous X-ray sources {ULXs} are extragalactic point sources
with luminosities that exceed the Eddington luminosity for
conventional stellar-mass black holes by factors of 10 - 100. It has
been hotly debated whether the ULXs are just common stellar-mass black
hole sources with beamed emission or whether they are sub-Eddington
sources that are powered by the long-sought intermediate mass black
holes {IMBH}. To firmly decide this question, one must obtain
dynamical mass measurements through photometric and spectroscopic
monitoring of the secondaries of these system. The crucial first step
is to establish the orbital period of a ULX, and arguably the best way
to achieve this goal is by monitoring its ellipsoidal light curve. The
extreme ULX NGC1313 X-2 provides an outstanding target for an orbital
period determination because its relatively bright optical counterpart
{V = 23.5} showed a 15% variation between two HST observations
separated by three months. This level of variability is consistent
with that expected for a tidally distorted secondary star. Here we
propose a set of 20 imaging observations with HST/WFPC2 to define the
orbital period. This would be the first photometric measurement of the
orbital period of a ULX binary. Subsequently, we will propose to
obtain spectroscopic observations to obtain its radial velocity
amplitude and thereby a dynamical estimate of its mass.

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:

18236-1 - Place +BB SPA Trim Relay back On-Line @ 150/18:26z

COMPLETED OPS NOTES: (None)

*********************** SCHEDULED***** SUCCESSFUL

FGS GSacq************** 08**************** 08
FGS REacq************** 04**************** 04
OBAD with Maneuver **** 24**************** 24

SIGNIFICANT EVENTS:

On DOY 2008/150 at approximately 18:26 GMT, Ops Request 18236 (Place
+BB SPA Trim Relay back On-Line) was successfully executed to place
the +BB SPA trim relay back on-line in FSW. Nominal system performance
was observed the following orbit and the +BB SPA was re-connected via
HMAC09 in orbit night. Battery temperatures have converged and
returned to an acceptable operating range of 0 to -3 degrees C. EPS
SEs will continue to closely monitor system and provide additional
updates as more data becomes available.