HUBBLE SPACE TELESCOPE - Continuing to Collect World Class Science

 

DAILY REPORT       #4957

 

PERIOD COVERED: 5am October 22 - 5am October 23, 2009 (DOY295/09:00z-296/09:00z)

 

OBSERVATIONS SCHEDULED

 

FGS 11788

 

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.

 

NIC 11416

 

NICMOS Parallel Thermal Background

 

Characterize the stability of the HST+NCS+Instrument thermal emission as

seen by NICMOS on secular scales. The data will be obtained using NIC3

and the F222M filter and will run throughout the SMOV4 activities as a

pure parallel program.

 

NIC 11417

 

NICMOS Detector Read noise and Dark Current

 

The NICMOS detector characteristics will be monitored during the entire

extent of the SMOV4 through a set of dark exposures. This will also

allow a determination of the detector temperature from bias

measurements. The data should be obtained in SAA-free orbits,

approximately every 24 hours. In addition, the detector read noise and

the detector shading profiles will be measured once a week.

 

NIC1/NIC2/NIC3 11820

 

NICMOS Post-SAA Calibration - CR Persistence Part 7

 

Internals for CR persistence

 

 

STIS/CCD 11844

 

CCD Dark Monitor Part 1

 

The purpose of this proposal is to monitor the darks for the STIS CCD.

 

STIS/CCD 11846

 

CCD Bias Monitor-Part 1

 

The purpose of this proposal is to 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.

 

WFC/ACS 11888

 

ACS Internal Flat Fields

 

The stability of the CCD flat fields will be monitored using the

calibration lamps and a sub-sample of the filter set. High signal

observations will be used to assess the stability of the pixel-to-pixel

flat field structure and to monitor the position of the dust motes.

 

WFC3/ACS/UVIS 11360

 

Star Formation in Nearby Galaxies

 

Star formation is a fundamental astrophysical process; it controls

phenomena ranging from the evolution of galaxies and nucleosynthesis to

the origins of planetary systems and abodes for life. The WFC3,

optimized at both UV and IR wavelengths and equipped with an extensive

array of narrow-band filters, brings unique capabilities to this area of

study. The WFC3 Scientific Oversight Committee (SOC) proposes an

integrated program on star formation in the nearby universe which will

fully exploit these new abilities. Our targets range from the

well-resolved R136 in 30 Dor in the LMC (the nearest super star cluster)

and M82 (the nearest starbursting galaxy) to about half a dozen other

nearby galaxies that sample a wide range of star-formation rates and

environments. Our program consists of broad band multiwavelength imaging

over the entire range from the UV to the near-IR, aimed at studying the

ages and metallicities of stellar populations, revealing young stars

that are still hidden by dust at optical wavelengths, and showing the

integrated properties of star clusters. Narrow-band imaging of the same

environments will allow us to measure star-formation rates, gas

pressure, chemical abundances, extinction, and shock morphologies. The

primary scientific issues to be addressed are: (1) What triggers star

formation? (2) How do the properties of star-forming regions vary among

different types of galaxies and environments of different gas densities

and compositions? (3) How do these different environments affect the

history of star formation? (4) Is the stellar initial mass function

universal or determined by local conditions?

 

WFC3/UV/ACS/WFC 11688

 

Exploring the Bottom End of the White Dwarf Cooling Sequence in the Open

Cluster NGC6819

 

The recent discovery by our group of an unexpectedly bright end of the

white-dwarf (WD) luminosity function (LF) of the metal-rich, old open

cluster NGC 6791 casts serious doubts on our understanding of the

physical process which rules the formation and the cooling of WDs. It is

clear at this point that the theory badly needs more observations. Here

we propose WFC3/UVIS and ACS/WFC HST observations reaching the bottom

end of the WD LF, for the first time in a solar-metallicity,

2.5-Gyr-old, populous open cluster: NGC 6819.

 

WFC3/UVIS 11630

 

Monitoring Active Atmospheres on Uranus and Neptune

 

We propose Snapshot observations of Uranus and Neptune to monitor

changes in their atmospheres on time scales of weeks and months, as we

have been doing for the past seven years. Previous Hubble Space

Telescope observations (including previous Snapshot programs 8634,

10170, 10534, and 11156), together with near-IR images obtained using

adaptive optics on the Keck Telescope, reveal both planets to be dynamic

worlds which change on time scales ranging from hours to (terrestrial)

years. Uranus equinox occurred in December 2007, and the northern

hemisphere is becoming fully visible for the first time since the early

1960s. HST observations during the past several years (Hammel et al.

2005, Icarus 175, 284 and references therein) have revealed strongly

wavelength-dependent latitudinal structure, the presence of numerous

visible-wavelength cloud features in the northern hemisphere, at least

one very long- lived discrete cloud in the southern hemisphere, and in

2006 the first clearly defined dark spot seen on Uranus. Long term

ground-based observations (Lockwood and Jerzekiewicz, 2006, Icarus 180,

442; Hammel and Lockwood 2007, Icarus 186, 291) reveal seasonal

brightness changes that seem to demand the appearance of a bright

northern polar cap within the next few years. Recent HST and Keck

observations of Neptune (Sromovsky et al. 2003, Icarus 163, 256 and

references therein) show a general increase in activity at south

temperate latitudes until 2004, when Neptune returned to a rather

Voyager-like appearance with discrete bright spots rather than active

latitude bands. Further Snapshot observations of these two dynamic

planets will elucidate the nature of long-term changes in their zonal

atmospheric bands and clarify the processes of formation, evolution, and

dissipation of discrete albedo features.

 

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).

 

WFC3/UVIS 11907

 

UVIS Cycle 17 Contamination Monitor

 

The UV throughput of WFC3 during Cycle 17 is monitored via weekly

standard star observations in a subset of key filters covering 200-600nm

and F606W, F814W as controls on the red end. The data will provide a

measure of throughput levels as a function of time and wavelength,

allowing for detection of the presence of possible contaminants.

 

WFC3/UVIS 11908

 

Cycle 17: UVIS Bowtie Monitor

 

Ground testing revealed an intermittent hysteresis type effect in the

UVIS detector (both CCDs) at the level of ~1%, lasting hours to days.

Initially found via an unexpected bowtie-shaped feature in flatfield

ratios, subsequent lab tests on similar e2v devices have since shown

that it is also present as simply an overall offset across the entire

CCD, i.e., a QE offset without any discernable pattern. These lab tests

have further revealed that overexposing the detector to count levels

several times full well fills the traps and effectively neutralizes the

bowtie. Each visit in this proposal acquires a set of three 3x3 binned

internal flatfields: the first unsaturated image will be used to detect

any bowtie, the second, highly exposed image will neutralize the bowtie

if it is present, and the final image will allow for verification that

the bowtie is gone.

 

WFC3/UVIS/IR 11644

 

A Dynamical-Compositional Survey of the Kuiper Belt: A New Window Into

the Formation of the Outer Solar System

 

The eight planets overwhelmingly dominate the solar system by mass, but

their small numbers, coupled with their stochastic pasts, make it

impossible to construct a unique formation history from the dynamical or

compositional characteristics of them alone. In contrast, the huge

numbers of small bodies scattered throughout and even beyond the

planets, while insignificant by mass, provide an almost unlimited number

of probes of the statistical conditions, history, and interactions in

the solar system. To date, attempts to understand the formation and

evolution of the Kuiper Belt have largely been dynamical simulations

where a hypothesized starting condition is evolved under the

gravitational influence of the early giant planets and an attempt is

made to reproduce the current observed populations. With little

compositional information known for the real Kuiper Belt, the test

particles in the simulation are free to have any formation location and

history as long as they end at the correct point. Allowing compositional

information to guide and constrain the formation, thermal, and

collisional histories of these objects would add an entire new dimension

to our understanding of the evolution of the outer solar system. While

ground based compositional studies have hit their flux limits already

with only a few objects sampled, we propose to exploit the new

capabilities of WFC3 to perform the first ever large-scale

dynamical-compositional study of Kuiper Belt Objects (KBOs) and their

progeny to study the chemical, dynamical, and collisional history of the

region of the giant planets. The sensitivity of the WFC3 observations

will allow us to go up to two magnitudes deeper than our ground based

studies, allowing us the capability of optimally selecting a target list

for a large survey rather than simply taking the few objects that can be

measured, as we have had to do to date. We have carefully constructed a

sample of 120 objects which provides both overall breadth, for a general

understanding of these objects, plus a large enough number of objects in

the individual dynamical subclass to allow detailed comparison between

and within these groups. These objects will likely define the core

Kuiper Belt compositional sample for years to come. While we have many

specific results anticipated to come from this survey, as with any

project where the field is rich, our current knowledge level is low, and

a new instrument suddenly appears which can exploit vastly larger

segments of the population, the potential for discovery -- both

anticipated and not -- is extraordinary.

 

FLIGHT OPERATIONS SUMMARY:

 

Significant Spacecraft Anomalies: (The following are preliminary reports

of potential non-nominal performance that will be investigated.)

 

HSTARS:

12051 - At 295/12:30:47 the SIC&DH safed. Telemetry indicated that the

           SIC&DH Pit toggle test failed.

 

 

COMPLETED OPS REQUEST:

18728-1 - Recycle SIC&DH after lock-up @ 295/1435z

18730-1 - Execute Safemode Recovery Macro @ 295/1755z

18729-2 - Recover NSSC1 back to Normal Mode 295/2001z

18731-1 - Re-enable ACR to Reset MEB of SIs @ 295/2005z

18732-0 - Re-enable NSSC-1 HV Protect Function @ 295/2115z

18733-0 - Recover the ESM, NCS CPL, and PCE @ 295/2141z

 

COMPLETED OPS NOTES: (None)

 

                       SCHEDULED      SUCCESSFUL 

FGS GSAcq               10                  09   

FGS REAcq               04                   03   

OBAD with Maneuver 08                   08              

 

 

SIGNIFICANT EVENTS:

 

Flash Report: SIC&DH lock-up

 

The PIT Toggle test failed at 295/12:30:47 The SIs were then transitioned to

their respective safe modes.

 

SIC&DH was recovered to NORMAL mode at 295/19:21z

 

Currently, the SIC&DH is in Fixed mode with all SIs in safe mode.

 

 

Flash Report: HV Protect Enable and ESM / NCS CPL / PCE Recovery

 

Ops Request 18732 to re-enable the NSSC-1 HV Protect sequence was

successfully completed at 295/21:14 UTC.

 

Ops Request 18733 followed and was successfully completed at 295/21:40

UTC, recovering the ESM up to its Operate mode, placing the NCS CPL in

its Standby state at a reservoir setpoint of -34 degC, and re-enabling

the PCE to restore visibility into various NCC telemetry.