HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

DAILY REPORT    # 4607

PERIOD COVERED: 5am May 08 - 5am May 09, 2008 (DOY 129/0900z - 130/0900z)

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.

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 i

mages. Each observation will need its own CRMAP, as different SAA

passages leave different imprints on the NICMOS detectors.

NIC2/WFPC2 11142

Revealing the Physical Nature of Infrared Luminous Galaxies at 0.3<z<2.7

Using HST and Spitzer

We aim to determine physical properties of IR luminous galaxies at

0.3<z<2.7 by requesting coordinated HST/NIC2 and MIPS 70um observations

of a unique, 24um flux-limited sample with complete Spitzer mid-IR

spectroscopy. The 150 sources investigated in this program have S{24um}

> 0.8mJy and their mid-IR spectra have already provided the majority

targets with spectroscopic redshifts {0.3<z<2.7}. The proposed

150~orbits of NIC2 and 66~hours of MIPS 70um will provide the physical

measurements of the light distribution at the rest-frame ~8000A and

better estimates of the bolometric luminosity. Combining these

parameters together with the rich suite of spectral diagnostics from the

mid-IR spectra, we will {1} measure how common mergers are among LIRGs

and ULIRGs at 0.3<z<2.7, and establish if major mergers are the drivers

of z>1 ULIRGs, as in the local Universe. {2} study the co-evolution of

star formation and blackhole accretion by investigating the relations

between the fraction of starburst/AGN measured from mid-IR spectra vs.

HST morphologies, L{bol} and z. {3} obtain the current best estimates of

the far-IR emission, thus L{bol} for this sample, and establish if the

relative contribution of mid-to-far IR dust emission is correlated with

morphology {resolved vs. unresolved}.

S/C 11163

Accreting Pulsating White Dwarfs in Cataclysmic Variables

Recent ground-based observations have increased the number of known

pulsating white dwarfs in close binaries with active mass transfer

{cataclysmic variables} from 5 to 11 systems. Our past Cycles 8 and 11

STIS observations of the first 2 known, followed by our Cycle 13 SBC

observations of the next 3 discovered, revealed the clear presence of

the white dwarf and increased amplitude of the pulsations in the UV

compared to the optical. The temperatures derived from the UV spectra

show 4 systems are much hotter than non-interacting pulsating white

dwarfs. A larger sample is needed to sort out the nature of the

instability strip in accreting pulsators i.e. whether effects of

composition and rotation due to accretion result in a well- defined

instability strip as a function of Teff.

WFPC2 11216

HST / Chandra Monitoring of a Dramatic Flare in the M87 Jet

As the nearest galaxy with an optical jet, M87 affords an unparalleled

opportunity to study extragalactic jet phenomena at the highest

resolution. During 2002, HST and Chandra monitoring of the M87 jet

detected a dramatic flare in knot HST-1 located ~1" from the nucleus.

Its optical brightness eventually increased seventy-fold and peaked in

2005; the X-rays show a similarly dramatic outburst. In both bands HST-1

is still extremely bright and greatly outshines the galaxy nucleus. To

our knowledge this is the first incidence of an optical or X-ray

outburst from a jet region which is spatially distinct from the core

source -- this presents an unprecedented opportunity to study the

processes responsible for non-thermal variability and the X-ray

emission. We propose five epochs of HST/WFPC2 flux monitoring during

Cycle 16, as well as seven epochs of Chandra/ACIS observation {5ksec

each, six Chandra epochs contemporary with HST}. At two of the HST/WFPC2

epochs we also gather spectral information, and at one epoch we will map

the magnetic field structure. The results of this investigation are of

key importance not only for understanding the nature of the X-ray

emission of the M87 jet, but also for understanding flares in blazar

jets, which are highly variable, but where we have never before been

able to resolve the flaring region in the optical or X-rays. These new

observations will allow us to track the decay phase of the giant flare,

and study smaller secondary flares such as seen late in 2006. Ultimately

we will test synchrotron emission models for the X-ray outburst,

constrain particle acceleration and loss timescales, and study the jet

dynamics associated with this flaring component.

WFPC2 11551

When degenerate stars collide: Understanding A New Explosion Phenomena

Explosive events seen at extragalactic distances mark the end-state of

violent and catastrophic physical processes. Most supernovae and

gamma-ray bursts (GRBs), in particular, are thought to herald the death

of massive stars and the birth of solar-mass black holes. A minority

fraction of GRBs, however, have been circumstantially associated with

the merger of degenerate systems (such as black holes and neutron

stars). These short-duration bursts are rare and difficult to localize,

with only about 2 dozen studied to any degree of detail to date. We

believe that we have finally discovered, in the last few days, one of

the tell-tale signatures of degenerate merger products --- a

"mini-supernova" from the non-relativistic ejecta left over after

merger. If true, this long-theorized phenomenon would be an entirely new

sort of explosion in the universe. In several rapidly executed visits,

HST, coupled with a recently approved Chandra DD proposal to search for

underlying afterglow, could make a substantial contribution to our

understanding of this phenomena by honing the physical parameters of the

event and helping to rule out alternatives. If we are correct in our

hypothesis, we have found the first clear cut observational signature in

the electromagnetic spectrum of what are expected to the be the dominant

sources of gravitational waves for advanced LIGO.

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                05                  05                  

FGS REacq                08                  08                  

OBAD with Maneuver  26                  26                  

SIGNIFICANT EVENTS: (None)