NASA Hubble Space Telescope Daily Report #4957
HUBBLE SPACE TELESCOPE DAILY REPORT #4957
Continuing to Collect World Class Science
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 1×1, 1×2, 2×1, and 2×2 bin settings at gain=1, and 1×1 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 3×3 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.
