HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

 

DAILY REPORT       #4667

 

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 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}.

 

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)