NASA Hubble Space Telescope Daily Report #4667
HUBBLE SPACE TELESCOPE DAILY REPORT #4667
Continuing to collect World Class Science
PERIOD COVERED: 5am August 4 – 5am August 5, 2008 (DOY 217/0900z-218/0900z)
OBSERVATIONS SCHEDULED
WFPC2 10877
A Snapshot Survey of the Sites of Recent, Nearby Supernovae
During the past few years, robotic {or nearly robotic} searches for supernovae {SNe}, most notably our Lick Observatory Supernova Search {LOSS}, have found hundreds of SNe, many of them in quite nearby galaxies {cz < 4000 km/s}. Most of the objects were discovered before maximum brightness, and have follow-up photometry and spectroscopy; they include some of the best-studied SNe to date. We propose to conduct a snapshot imaging survey of the sites of some of these nearby objects, to obtain late-time photometry that {through the shape of the light and color curves} will help reveal the origin of their lingering energy. The images will also provide high-resolution information on the local environments of SNe that are far superior to what we can procure from the ground. For example, we will obtain color-color and color-magnitude diagrams of stars in these SN sites, to determine the SN progenitor masses and constraints on the reddening. Recovery of the SNe in the new HST images will also allow us to actually pinpoint their progenitor stars in cases where pre- explosion images exist in the HST archive. This proposal is an extension of our successful Cycle 13 snapshot survey with ACS. It is complementary to our Cycle 15 archival proposal, which is a continuation of our long-standing program to use existing HST images to glean information about SN environments.
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 11172
Defining Classes of Long Period Variable Stars in M31
We propose a thrifty but information-packed investigation {1440 exposures total} with NICMOS F205W, F160W and F110W providing crucial information about Long Period Variables in M31, at a level of detail that has recently allowed the discovery of new variable star classes in the Magellanic Clouds, a very different stellar population. These observations are buttressed by an extensive map of the same fields with ACS and WFPC2 exposures in F555W and F814W, and a massive ground-based imaging patrol producing well-sampled light curves for more than 400,000 variable stars. Our primary goal is to collect sufficient NIR data in order to analyze and classify the huge number of long-period variables in our catalog {see below} through Period-Luminosity {P/L} diagrams. We will produce accurate P/L diagrams for both the bulge and a progression of locations throughout the disk of M31. These diagrams will be similar in quality to those currently in the Magellanic Clouds, with their lower metallicity, radically different star formation history, and larger spread in distance to the variables. M31 offers an excellent chance to study more typical disk populations, in a manner which might be extended to more distant galaxies where such variables are still visible, probing a much more evenly spread progenitor age distribution than cepheids {and perhaps useful as a distance scale alternative or cross-check}. Our data will also provide a massive and unique color-magnitude dataset, and allow us to confirm the microlensing nature of a large sample of candidate lensed sources in M31. We expect that this study will produce several important results, among them a better understanding of P/L and P/L-color relations for pulsating variables which are essential to the extragalactic distance ladder, will view these variables at a common distance over a range of metallicities {eliminating the distance- error vs. metallicity ambiguity between the LMC and SMC}, allow further insight into possible faint-variable mass-loss for higher metallicities, and in general produce a sample more typical of giant disk galaxies predominant in many studies.
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.
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}.
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 11203
A Search for Circumstellar Disks and Planetary-Mass Companions around Brown Dwarfs in Taurus
During a 1-orbit program in Cycle 14, we used WFPC2 to obtain the first direct image of a circumstellar disk around a brown dwarf. These data have provided fundamental new constraints on the formation process of brown dwarfs and the properties of their disks. To search for additional direct detections of disks around brown dwarfs and to search for planetary-mass companions to these objects, we propose a WFPC2 survey of 32 brown dwarfs in the Taurus star-forming region.
WFPC2 11796
WFPC2 Cycle 16 Decontaminations and Associated Observations
This proposal is for the WFPC2 decons. Also included are instrument monitors tied to decons: photometric stability check, focus monitor, pre- and post-decon internals (bias, intflats, kspots, & darks), UV throughput check, VISFLAT sweep, and internal UV flat check.
WFPC2 11797
Supplemental WFPC2 CYCLE 16 Intflat Linearity Check and Filter Rotation Anomaly Monitor
Supplemental observations to 11029, to cover period from Aug 08 to SM4. 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 11022 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.
Note: These are supplemental observations to cover June to SM4 (oct 8 ’08) + 6 months.
FLIGHT OPERATIONS SUMMARY:
Significant Spacecraft Anomalies: (The following are preliminary reports of potential non-nominal performance that will be investigated.)
HSTARS:
11424 – REAcq (1,2,1) results in Fine Lock Backup (1,0,1)
At 217/19:34:46, REAcq (1,2,1) scheduled from 217/19:30:54 – 19:38:28 resulted in Fine Lock Back-up (1,0,1) using FGS-1. Received QF2STOPF and QSTOP stop flags. OBAD #1: V1 1204.78, V2 1769.92, V3 -785.27, RSS 2280.52 arc seconds. OBAD #2: V1 -2.69, V2 -1.74, V3 0.36, RSS 3.23 arc seconds. OBAD MAP was not scheduled.
Possible observations affected: WFPC Proposal 11178, Observation 77-80.
COMPLETED OPS REQUEST: (None)
COMPLETED OPS NOTES: (None)
SCHEDULED SUCCESSFUL FGS GSacq 11 11 FGS REacq 02 02 OBAD with Maneuver 28 28
SIGNIFICANT EVENTS: (None)