HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science



DAILY REPORT #4905



PERIOD COVERED: 5am August 7 - 5am August 9, 2009 (DOY 219/09:00z-221/09:00z)



OBSERVATIONS SCHEDULED



WFC3/UVI 12003



The Impact Event on Jupiter in 2009



An image of Jupiter taken on 19 July 2009 at 15 UT showed an anomalous

feature in the southern hemisphere. The world-wide community responded

with observations, and the subsequent data strongly suggest that an

impact occurred during the 8 hours preceding that discovery image. The

Hubble Space Telescope is the only facility that can provide

high-spatial- resolution visible images of the impact site, and the only

facility that can provide UV images that show the impactor's effect on

the Jovian stratosphere. We request 7 orbits of HST time to characterize

this rare event. We hope that two orbits can be as soon as is feasible

(Wednesday or Thursday, 22 or 23 July). We would like a second pair

several days later, perhaps Saturday. We request another 2 orbits the

following week. The last, seventh, orbit can be several weeks or a month

later.



STIS/CCD 11889



Photometric Cross-Calibration using Stellar Flux Standards



A) Verify the ACS HRC and WFC photometric calibrations with a repeat

visit to one of the three primary WDs. B) Measure the change in

sensitivity with time for bright stars (which would include any small

CTE contributions). C) Continue to investigate the ~2% discrepancy

between ACS flux calibration and that of STIS (ACS ISR 2007-06). The

goal is to measure any filter bandpass shifts in ACS or rule out the

possibility of shifts as the primary contributors to the ACS/STIS

discrepancy for cool stars.



STIS/CCD 11846



CCD Bias Monitor-Part 1



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.



STIS/CCD 11844



CCD Dark Monitor Part 1



Monitor the darks for the STIS CCD.



WFC3/UVI/IR 11832



The Structure and Physics of the Youngest Radio Galaxies



We propose to obtain X-ray images and spectra of two of the nearest and

X-ray brightest compact symmetric objects. These objects are radio

sources which have begun ejecting radio plasma within the last nsim

10000 years. The purpose of these observations is to discover their

X-ray structure, measure their X-ray spectra and test the Wilson-Colbert

hypothesis regarding the formation of radio-loud AGN. CSOs are ideal

targets for this test because they are very small and very young. By

targeting the very nearest objects we assure ourselves of the highest

possible physical resolution. We are particularly looking for binary

black holes (possibly found for one of our objects already) and/or

nascent NLRs.



WFC3 11808



WFC3 UVIS Bowtie Monitor



The UVIS detector was observed during ground testing to occasionally

exhibit flat field and dark variations with a bowtie pattern. These

variations are most significant as ~1% flat field (gain) variations

across the field of view. It is believed that this represents a state or

condition into which the detector can transition for reasons and under

circumstances which are not currently understood. It is also very

unlikely that most science observations will determine the state (bowtie

or no-bowtie) of the detector. Ground test data indicates that this

state is long lived (many hours to ~one day). Hysteresis or memory of

past light exposure is also associated with this state.



Recent evidence suggests that exposing the detector to ~200k to 500k

electrons may quench this state. This proposal obtains an internal flat

field sequence of three exposures: one at 10x full well with two at 0.5x

full well immediately before and after. Each exposure is 3x3 binned to

reduce the data volume required.



These visits should be scheduled 2x per day until further direction is

provided.



ACS/WFC3 11734



The Hosts of High Redshift Gamma-Ray Bursts



Gamma-ray bursts are the most luminous explosive events known, acting as

beacons to the high redshift universe. Long duration GRBs have their

origin in the collapse of massive stars and thus select star forming

galaxies across a wide range of redshift. Due to their bright afterglows

we can study the details of GRB host galaxies via absorption

spectroscopy, providing redshifts, column densities and metallicities

for galaxies far too faint to be accessible directly with current

technology. We have already obtained deep ground based observations for

many hosts and here propose ACS/WFC3 and WFC3 observations of the fields

of bursts at z>3 which are undetected in deep ground based images. These

observations will study the hosts in emission, providing luminosities

and morphologies and will enable the construction of a sample of high-z

galaxies with more detailed physical properties than has ever been

possible before.



FGS 11704



The Ages of Globular Clusters and the Population II Distance Scale



Globular clusters are the oldest objects in the universe whose age can

be accurately determined. The dominant error in globular cluster age

determinations is the uncertain Population II distance scale. We propose

to use FGS 1r to obtain parallaxes with an accuracy of 0.2

milliarcsecond for 9 main sequence stars with [Fe/H] < -1.5. This will

determine the absolute magnitude of these stars with accuracies of 0.04

to 0.06mag. This data will be used to determine the distance to 24

metal-poor globular clusters using main sequence fitting. These

distances (with errors of 0.05 mag) will be used to determine the ages

of globular clusters using the luminosity of the subgiant branch as an

age indicator. This will yield absolute ages with an accuracy 5%, about

a factor of two improvement over current estimates. Coupled with

existing parallaxes for more metal-rich stars, we will be able to

accurately determine the age for globular clusters over a wide range of

metallicities in order to study the early formation history of the Milky

Way and provide an independent estimate of the age of the universe.



The Hipparcos database contains only 1 star with [Fe/H] < -1.4 and an

absolute magnitude error less than 0.18 mag which is suitable for use in

main sequence fitting. Previous attempts at main sequence fitting to

metal-poor globular clusters have had to rely on theoretical

calibrations of the color of the main sequence. Our HST parallax program

will remove this source of possible systematic error and yield distances

to metal-poor globular clusters which are significantly more accurate

than possible with the current parallax data. The HST parallax data will

have errors which are 10 times smaller than the current parallax data.

Using the HST parallaxes, we will obtain main sequence fitting distances

to 11 globular clusters which contain over 500 RR Lyrae stars. This will

allow us to calibrate the absolute magnitude of RR Lyrae stars, a

commonly used Population II distance indicator.



ACS/WFC3 11695



Searching for the Bottom of the Initial Mass Function



The measurement of the minimum mass of the IMF would provide a

fundamental test of theories of star and planet formation. In a Cycle 13

program, we used ACS and ground-based near-IR imaging and spectroscopy

to measure the IMF down to a completeness limit of 10 M_Jup (i~24) in a

800"x1000" area in the southern subcluster of the Chamaeleon I

star-forming region (2 Myr, 160 pc). There is no sign of a low-mass

cutoff in this IMF measurement. To provide a better constraint on the

minimum mass of the IMF, we propose to obtain ACS images of this field

again and use the two ACS epochs to identify substellar cluster members

down to the detection limit of the data (i~27) via their proper motions.

In this way, we will improve the completeness limit of our IMF

measurement to 3 M_Jup. In addition, to improve the number statistics of

our measurement of the substellar IMF in Chamaeleon I, we propose to

double the number of objects in the IMF sample by performing ACS imaging

of a second field toward the northern subcluster.



WFC3/UVI/IR 11685



Supermassive Neutron Stars or Odd Binaries: Searching for Companions to

Pulsars NGC 6440B and Terzan 5J



Recent sensitive pulsar searches of globular clusters uncovered four

pulsars with very high inferred masses, between 1.7 and 2.7 solar

masses. These strongly constrain the behaviour of matter in the

ultra-dense interiors of neutron stars, since for most models such

massive neutron stars could not exist. All four masses are inferred from

the measured advance of periastron with time, under the assumption that

it is due to General Relativity only. Here, we propose to test whether

part of the observed periastron advance could be induced by the

quadrupole moment of a suitably large, rotationally distorted companion.

We infer the radii such companions need to have and show that they would

be relatively bright, easily detectable with HST. For one pulsar, M 5B,

we find a plausible candidate counterpart in archival data. We propose

to use 2 orbits with WFC3 to search for suitably large counterparts to

two of the other systems, including the one with the highest inferred

mass.



WFC3/UVI 11680



The Main Sequence Luminosity Function of Low-Mass Globular Clusters



Theoretical work indicates that the dynamical evolution of globular

clusters of low mass and low central concentration is strongly

determined by mass-loss processes, such as stellar evaporation and tidal

stripping, that can eventually lead to cluster dissolution. In fact,

mass loss and cluster disruption is now considered to be a viable

explanation for the form of the faint end of the Milky Way globular

cluster luminosity function. A clear observational demonstration of the

prevalence of cluster mass-loss would have ramifications not only for

the dynamical evolution of individual globular clusters and their

internal stellar mass distributions, but also for the relationships

between halo field and cluster stars and the properties of globular

cluster systems in galaxies. Our previous WFPC2 imaging of the low-mass

diffuse halo cluster Palomar 5 revealed a main sequence deficient in

stars compared to other low-concentration globular clusters of much

higher mass, consistent with there having been a considerable loss of

stars from this system. But is Pal 5 typical of low-mass,

low-concentration halo clusters? We propose to place the mass-loss

scenario on a firm observational footing (or otherwise) by using WFC3

imaging to measure the main-sequence stellar mass functions of two of

the lowest-mass lowest-concentration globular clusters in the Milky Way,

AM-4 and Palomar 13, in order to search for analogous evidence of

stellar depletion.



ACS/WFC3 11669



The Origins of Short Gamma-Ray Bursts



During the past decade extraordinary progress has been made in

determining the origin of long- duration gamma-ray bursts. It has been

conclusively shown that these objects derive from the deaths of massive

stars. Nonetheless, the origin of their observational cousins,

short-duration gamma-ray bursts (SGRBs) remains a mystery. While SGRBs

are widely thought to result from the inspiral of compact binaries, this

is a conjecture. SGRBs have been found in elliptical galaxies, Abell

Clusters, star-forming dwarfs and even an edge-on spiral. Whether they

primarily result from an old population, a young population, or rapid

evolution of binaries in globular clusters remains open.



Here we propose to employ two related sets of observations which may

dramatically advance our understanding of short bursts. The first is a

variant of a technique that we pioneered and used to great effect in

elucidating the origins of long-duration bursts. We will examine a

statistical sample of hosts and measure the degree to which SGRB

locations trace the red or blue light of their hosts, and thus old or

young stellar populations. This will allow us to study the demographics

of the SGRB population in a manner largely free of the distance

dependent selection effects which have so far bedeviled this field. In

the second line of attack we will use two targets of opportunity to

obtain extremely precise positions of up to two nearby bursts -- one on

a star-forming galaxy and the other on a elliptical. Observation of the

star-formation galaxy could link at least some bursts directly to a

young population; however, a discovery in later images of a globular

cluster at the site of the explosion in an elliptical would provide

revolutionary evidence that SGRBs are formed from compact binaries.



WFC3/UVI 11657



The Population of Compact Planetary Nebulae in the Galactic Disk



We propose to secure narrow- and broad-band images of compact planetary

nebulae (PNe) in the Galactic Disk to study the missing link of the

early phases of post-AGB evolution. Ejected AGB envelopes become PNe

when the gas is ionized. PNe expand, and, when large enough, can be

studied in detail from the ground. In the interim, only the HST

capabilities can resolve their size, morphology, and central stars. Our

proposed observations will be the basis for a systematic study of the

onset of morphology. Dust properties of the proposed targets will be

available through approved Spitzer/IRS spectra, and so will the

abundances of the alpha- elements. We will be able thus to explore the

interconnection of morphology, dust grains, stellar evolution, and

populations. The target selection is suitable to explore the nebular and

stellar properties across the Galactic Disk, and to set constraints on

the galactic evolutionary models through the analysis of metallicity and

population gradients.



WFC3/UVI 11628



Globular Cluster Candidates for Hosting a Central Black Hole



We are continuing our study of the dynamical properties of globular

clusters and we propose to obtain surface brightness profiles for high

concentration clusters. Our results to date show that the distribution

of central surface brightness slopes do not conform to standard models.

This has important implications for how they form and evolve, and

suggest the possible presence of central intermediate-mass black holes.

From our previous archival proposals (AR-9542 and AR- 10315), we find

that many high concentration globular clusters do not have flat cores or

steep central cusps, instead they show weak cusps. Numerical simulations

suggest that clusters with weak cusps may harbor intermediate-mass black

holes and we have one confirmation of this connection with omega

Centauri. This cluster shows a shallow cusp in its surface brightness

profile, while kinematical measurements suggest the presence of a black

hole in its center. Our goal is to extend these studies to a sample

containing 85% of the Galactic globular clusters with concentrations

higher than 1.7 and look for objects departing from isothermal behavior.

The ACS globular cluster survey (GO-10775) provides enough objects to

have an excellent coverage of a wide range of galactic clusters, but it

contains only a couple of the ones with high concentration. The proposed

sample consists of clusters whose light profile can only be adequately

measured from space-based imaging. This would take us close to

completeness for the high concentration cases and therefore provide a

more complete list of candidates for containing a central black hole.

The dataset will also be combined with our existing kinematic

measurements and enhanced with future kinematic studies to perform

detailed dynamical modeling.



WFC3/UVI 11615



Hunting for Optical Companions to Binary MSPs in Globular Clusters



Here we present a proposal which exploits the re-newed potential of HST

after the Service Mission 4 for probing the population of binary

Millisecond Pulsars (MSPs) in Globular Clusters. In particular we intend

to: (1) extend the search for optical counterparts in Terzan 5, by

pushing the performance of the WFC3 IR channel to sample the entire MS

extension down to M=0.1 Mo; (2) perform a deep multi-band search of MSP

companions with the WFC3, in 3 clusters (namely NGC6440, M28 and M5),

where recent radio observations have found particularly interesting

objects; (3) derive an accurate radial velocity (with STIS) of the

puzzling optical companion COM6266B recently discovered by our group, to

firmly assess its cluster membership. This program is the result of a

large collaboration among the three major groups (lead by Freire, Ransom

and Possenti) which are performing extensive MSP search in GCs in the

radio bands, and our group which has a large experience in performing

accurate stellar photometry in crowded environments. This collaboration

has produced a number of outstanding discoveries. In fact, three of the

6 optical counterparts to binary MSP companions known to date in GCs

have been discovered by our group. The observations here proposed would

easily double/triple the existing sample of known MSP companions,

allowing the first meaningful approach to the study of the formation,

evolution and recycling process of pulsar in GCs. Moreover, since most

of binary MSPs in GCs are thought to form via stellar interactions in

the high density core regions, the determination of the nature of the

companion and the incidence of this collisionally-induced population has

a significant impact on our knowledge of the cluster dynamics. Even more

interesting, the study of the optical companions to NSs in GCs allows

one to derive tighter constraints (than those obtainable for NS binaries

in the Galactic field) on the system properties. This has, in turn, an

intrisic importance for fundamental physics, since it offers the

opportunity of measuring the mass of the NS and hence constraining the

equation of state of matter at the nuclear equilibrium density.



ACS/WFC3 11599



Distances of Planetary Nebulae from SNAPshots of Resolved Companions



Reliable distances to individual planetary nebulae (PNe) in the Milky

Way are needed to advance our understanding of their spatial

distribution, birthrates, influence on galactic chemistry, and the

luminosities and evolutionary states of their central stars (CSPN). Few

PNe have good distances, however. One of the best ways to remedy this

problem is to find resolved physical companions to the CSPN and measure

their distances by photometric main-sequence fitting. We have previously

used HST to identify and measure probable companions to 10 CSPN, based

on angular separations and statistical arguments only. We now propose to

use HST to re-observe 48 PNe from that program for which additional

companions are possibly present. We then can use the added criterion of

common proper motion to confirm our original candidate companions and

identify new ones in cases that could not confidently be studied before.

We will image the region around each CSPN in the V and I bands, and in

some cases in the B band. Field stars that appear close to the CSPN by

chance will be revealed by their relative proper motion during the 13+

years since our original survey, leaving only genuine physical

companions in our improved and enlarged sample. This study will increase

the number of Galactic PNe with reliable distances by 50 percent and

improve the distances to PNe with previously known companions.



WFC3/UVI 11580



Watching Young Planetary Nebulae Grow: The Movie



The development of magneto-hydro gas dynamical models is the key to the

understanding of both the physics (processes) and astronomy (initial

conditions) of astrophysical nebulae of all sorts. The models are

reaching their highest degree of accuracy when applied to and compared

against pre Planetary Nebulae (pPNe) thanks to the simplicity, relative

lack of extinction, and the detail of the imaging and kinematic data

that have bcome available for these objects. The primary barrier to

progress is inadequate kinematic data of pPNe against which the

predictions models can be tested. Unlike PNe, pPNe do not emit emission

lines for detailed Doppler measurements. Therefore it is essential to

find another way to monitor the morphological evolution.



Only HST can uncover the dynamics of the growth patterns by subtracting

multi-epoch images spanning a decade or more. We have selected four pPNe

with highly collimated outflows in different evolutionary stages for

which high-quality first epoch images were obtained from 1996 to 2002.

All of them display regularly shaped thin rims, sharp edges, and

symmetric pairs of knots or bowshocks that are ideal for our purposes.

We will closely mimic many of the earlier exposures using ACS and to

monitor changes in structures. The morphology and its evolution will be

compared to 3-D MHD models with adaptive grids in order to build a far

clearer picture of the nuclear geometry which shaped the outflows and

constrained their propagation to the present. We shall also obtain R, J,

and H images for use with a 3-D dust radiative transfer code LELUYA to

model the dust distribution deep into the nuclear zones.



WFC3/UVI/IR 11570



Narrowing in on the Hubble Constant and Dark Energy



A measurement of the Hubble constant to a precision of a few percent

would be a powerful aid to the investigation of the nature of dark

energy and a potent "end-to-end" test of the present cosmological model.

In Cycle 15 we constructed a new, streamlined distance ladder utilizing

high-quality type Ia supernova data and observations of Cepheids with

HST in the near-IR to minimize the dominant sources of systematic

uncertainty in past measurements of the Hubble constant and reduce its

total uncertainty to a little under 5%. Here we propose to exploit this

new route to reduce the remaining uncertainty by more than 30%,

translating into an equal reduction in the uncertainty of the equation

of state of dark energy. We propose three sets of observations to reach

this goal: a mosaic of NGC 4258 with WFC3 in F160W to triple its sample

of long period Cepheids, WFC3/F160W observations of the 6 ideal SN Ia

hosts to triple their samples of Cepheids, and observations of NGC 5584

the host of a new SN Ia, SN 2007af, to discover and measure its Cepheids

and begin expanding the small set of SN Ia luminosity calibrations.

These observations would provide the bulk of a coordinated program aimed

at making the measurement of the Hubble constant one of the leading

constraints on dark energy.



WFC3/UVI 11565



A Search for Astrometric Companions to Very Low-Mass, Population II

Stars



We propose to carry out a SNAPshot search for astrometric companions in

a subsample of very low-mass, halo subdwarfs identified within 120

parsecs of the Sun. These ultra-cool M subdwarfs are local

representatives of the lowest-mass H-burning objects from the Galactic

Population II. The expected 3-4 astrometric doubles that will be

discovered will be invaluable in that they will be the first systems

from which gravitational masses of metal-poor stars at the bottom of the

main sequence can be directly measured.



ACS/WFC3 11564



Optical and Ultraviolet Photometry of Isolated Neutron Stars



We propose ultraviolet and B-band observations of 5 nearby, thermally

emitting neutron stars. These data will measure the Rayleigh-Jeans tails

of their spectra, providing a vital complement to X-ray spectroscopy and

helping to constrain atmospheric models, working toward the ultimate

goal of unraveling the physics of neutron stars. With these data we will

have good-quality optical and UV data for the full sample of these

objects, allowing detailed comparisons between them. Finally, the data

should allow us to measure proper motions for one or two objects, and

will serve as the reference data for the remaining objects; such proper

motions allow ages to be determined for these objects by tracing them

back to likely birth locations.



WFC3/UVI/IR 11557



The Nature of Low-Ionization BAL QSOs



The rare subclass of optically-selected QSOs known as low-ionization

broad absorption line (LoBAL) QSOs show signs of high-velocity gas

outflows and reddened continua indicative of dust obscuration. Recent

studies show that galaxies hosting LoBAL QSOs tend to be ultraluminous

infrared systems that are undergoing mergers, and that have dominant

young (< 100 Myr) stellar populations. Such studies support the idea

that LoBAL QSOs represent a short- lived phase early in the life of

QSOs, when powerful AGN-driven winds are blowing away the dust and gas

surrounding the QSO. If so, understanding LoBALs would be critical in

the study of phenomena regulating black hole and galaxy evolution, such

as AGN feedback and the early stages of nuclear accretion. These

results, however, come from very small samples that may have serious

selection biases. We are therefore taking a more aggressive approach by

conducting a systematic multiwavelength study of a volume limited sample

of LoBAL QSOs at 0.5 < z < 0.6 drawn from SDSS. We propose to image

their host galaxies in two bands using WFC3/UVIS and WFC3/IR to study

the morphologies for signs of recent tidal interactions and to map their

interaction and star forming histories. We will thus determine whether

LoBAL QSOs are truly exclusively found in young merging systems that are

likely to be in the early stages of nuclear accretion.



COS 11515



Post-SM4 Cross-Instrument Light Leak Test



This proposal is based on SMOV Activity COS-37 (SMOV4 Light Leak Test).



This activity consists of a set of external exposures designed to

determine whether a particular science instrument (SI) is susceptible to

light leaks resulting from photons escaping from the calibration system

of another SI. For the identified combination of SIs (see list below),

the SI assumed to be the light source will carry out a calibration

activity while, in parallel, the other SI will perform an external

exposure. The test is designed to detect gross light leaks that may

affect science data during typical calibration lamp exposure sequences.

The test will provide an initial estimate of the amount of contamination

present. Follow-up observations for cases where light is detected may be

warranted. The most likely cases for light leaking out of an instrument

will be configurations with COS as prime when it is in TAGFLASH mode,

with another SI exposing on the sky in parallel. In TAGFLASH mode, the

COS external shutter is open and a PtNe wavelength calibration lamp is

flashed periodically for short intervals (5-30 seconds) during the

science exposure.



We use CVZ targeting of regions of sky near the orbit north pole

position in order to minimize the number of orbits required and the

impact to the existing SMOV4 timeline. All COS external exposures will

be centered with the COS primary science aperture on a blank region of

sky. However, bright object checks will need to be performed by the COS

team after selection of the final target positions, which depend upon

time of execution.



This test is based on the following guidelines:



1) Check new instruments as source and sink (WFC3 & COS). Check both

WFC3/UVIS and WFC3/IR. Check COS/FUV only if a problem is seen for

COS/NUV imaging mode. COS FUV is not currently part of this proposal.



2) Check known issues (e.g., WFPC2->ACS/WFC and NICMOS->WFPC2, with the

obvious substitution of WFC3 for WFPC2).



3) STIS and ACS/SBC will not be used in parallel with COS externals, and

therefore will not require testing as light sinks. They will not be

checked as sources either in this proposal.



4) STIS and ACS/SBC are not likely to be used often with COS internals

and therefore are not tested in this proposal.



5) Check ACS/SBC later only if a problem is seen for ACS/HRC (no problem

seen previously for WFPC2 -> ACS/HRC).



6) NICMOS is not likely to be used often with COS externals or COS

internals, and therefore requires testing only with WFC3. However, the

experimental design allows NICMOS to be tested as a source with COS as

sink.



7) There are no known problems for axial bay to axial bay cross

contamination (ACS <-> STIS or ACS <-> NICMOS or STIS <-> NICMOS), so no

problems are expected for NICMOS <-> COS. The specific combinations of

SIs to be tested for light leakage and unwanted light detection are as

follows: 1. With the COS External (PtNe TAGFLASH) and Internal (PtNe)

calibration lamp as the potential source, check for potential detections

by: ACS/WFC, ACS/HRC, WFC3/UVIS, and WFC3/IR 2. With the WFC3 Internal

(Tungsten) calibration lamp as a potential source, check for potential

detections by: ACS/WFC, ACS/HRC, and COS/NUV 3. With the ACS Internal

(Tungsten) calibration lamp as a potential source, check for potential

detections by: WFC3/UVIS, WFC3/IR, and COS/NUV 4. With the NICMOS

(Quartz Halogen) calibration lamp as the potential source, check for

potential detections by: WFC3/UVIS, WFC3/IR, and COS/NUV



Pre-requisite proposals that must be executed prior to this proposal

include: COS-06 NUV Detector Functional ACS-20 UV Sensitivity, Geometric

Distortion & Flat-field Uniformity ACS-11 HRC Sensitivity, Geometric

Distortion & Flat-field Stability NIC-04 NICMOS Filter Wheel Test

WFC3-33 UVIS Dark, Read Noise, and Background WFC3-34 IR Dark, Read

Noise, and Background



COS 11488



Internal FUV Wavelength Verification



This program will be executed after the uplink of the OSM1 position

updates derived from the determination of the wavelength-scale zero

points and desired spectral ranges for each grating in activity COS29

(program 11487 - COS FUV Internal/External Wavelength Scales). This

program will verify that the operational spectral ranges for each

grating, central wavelength, and FP-POS are those desired. Subsequent to

a successful verification, COS FUV ERO observations that require

accurate wavelength scales (if any) and FUV science can be enabled. An

internal wavelength calibration spectrum using the default PtNe lamp

(lamp 1) with each FUV grating at each central wavelength setting and

each FP-POS position will be obtained for the verification. Additional

exposures and waits between certain exposures will be required to avoid

- and to evaluate - mechanism drifts.



COS 11475



COS Internal NUV Wavelength Verification



This program will be executed after the uplink of the OSM2 position

updates derived from the determination of the wavelength-scale zero

points and desired spectral ranges for each grating in activity COS14

(program 11474 - COS NUV Internal/External Wavelength Scales). This

program will verify that the operational spectral ranges for each

grating, central wavelength, and FP-POS are those desired. Subsequent to

a successful verification, COS NUV ERO observations and NUV science can

be enabled. An internal wavelength calibration spectrum using the

default PtNe lamp (lamp 1) with each NUV grating at each central

wavelength setting and each FP-POS position will be obtained for the

verification. Additional exposures and waits between certain exposures

will be required to avoid - and to evaluate - mechanism drifts.



ACS 11465



ACS CCD Monitoring and Calibration for WFC3



This program is a smaller version of our routine CCD monitoring program,

designed to run throughout SMOV, after which our regular Cycle 17 CAL

proposal will begin. This program obtains the bias and dark frames

needed to generate reference files for calibrating science data, and

allows us to monitor detector noise and the growth of hot pixels.



WFC3 11446



WFC3 UVIS Dark Current, Readnoise, and CTE



This proposal obtains full-frame, four-amp readout bias and dark frames

at regularly-spaced intervals throughout SMOV in order to assess and

monitor dark current, bad (warm, hot, dead) pixels, and readnoise. In

addition, a set of internals using the WFC3 calsystem are taken to

provide a baseline CTE measurement. WFC3-33



STIS20 11402



STIS-20 NUV MAMA Dark Monitor



The STIS NUV-MAMA dark current is dominated by a phosphorescent glow

from the detector window. Meta-stable states in this window are

populated by cosmic ray impacts, which, days later, can be thermally

excited to an unstable state from which they decay, emitting a UV

photon. The equilibrium population of these meta-stable states is larger

at lower temperatures; so warming up the detector from its cold safing

will lead to a large, but temporary, increase in the dark current.



To monitor the decay of this glow, and to determine the equilibrium dark

current for Cycle 17, four 1380s NUV-MAMA ACCUM mode darks should be

taken each week during the SMOV period. Once the observed dark current

has reached an approximate equilibrium with the mean detector

temperature, the frequency of this monitor can be reduced to one pair of

darks per week.



STIS19 11390



STIS-19 FUV MAMA Dark Measure



The STIS MAMA HV power supplies are turned on only during each day's

block of SAA-free orbits. The FUV MAMA dark current glow has been

determined to increase with the length of time the FUV HV power supply

has been on. The rate of this daily increase has changed over the years

and also appears to be sensitive to temperature. To measure the rate at

which the dark current increases, as soon as possible after the

completion of STIS-17 (11350) completes a series of five 1380s FUV MAMA

dark exposures spread over 5 or more orbits of a single SAA period will

be taken. A second block of five exposures should be done near the end

of the SMOV period when the temperature of the aft shroud and STIS are

in the range expected for normal Cycle 17 operations.



FLIGHT OPERATIONS SUMMARY:



Significant Spacecraft Anomalies: (The following are preliminary reports

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



HSTARS:

11967 - GSAcq(1,2,1) at 219/18:09:02 resulted in Fine Lock Backup using FGS-1.



Observations possibly affected: ACS 88-91 Proposal ID# 11515,

COS 224-230 Proposal ID# 11515, STIS 87 Proposal ID# 11390,

WFC3 78-79 Proposal ID# 11515.



11970 - GSAcq(1,2,1) at 221/22:06:19 acquired in fine lock backup on FGS

1, scan step limit exceeded on FGS 1 @ 221/2206z.



Observations possibly affected: WFC3 124 - 127, Proposal ID# 11628.





COMPLETED OPS REQUEST:

18676-0 - Null genslew for proposal 11503 - slot 1 @ 219/1546z





COMPLETED OPS NOTES: (None)



SCHEDULED SUCCESSFUL

FGS GSAcq 26 26

FGS REAcq 19 19

OBAD with Maneuver 24 24



SIGNIFICANT EVENTS: (None)