HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science



DAILY REPORT #4913



PERIOD COVERED: 5am August 19 - 5am August 20, 2009 (DOY 231/09:00z-232/09:00z)



OBSERVATIONS SCHEDULED



ACS/WFC3 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.



FGS 11874



Monitoring FGS2R2 S-Curves after SMOV4



This proposal satisfies the near-term requirement associated with SMOV4

activity OTA/FGS-10, as well as the long term Cycle 17 requirement to

monitor the post-SM4 evolution of the FGS2R2 S-curves stability during

its first year on orbit. The S-curves will be obtained from Trans mode

observations of stars (point sources) at several locations in the FGS2R2

FOV in order to monitor both global and differential (i.e.,

field-dependent) changes. At each location, both F583W and PUPIL

S-curves will be obtained. Stars in the M35 cluster will be used for

this proposal since the field lies very near the ecliptic and can

therefore be observed by HST at two Orients from August to May.



STIS/CCD 11567



Boron Abundances in Rapidly Rotating Early-B Stars



Models of rotation in early-B stars predict that rotationally driven

mixing should deplete surface boron abundances during the main-sequence

lifetime of many stars. However, recent work has shown that many boron

depleted stars are intrinsically slow rotators for which models predict

no depletion should have occurred, while observations of nitrogen in

some more rapidly rotating stars show less mixing than the models

predict. Boron can provide unique information on the earliest stages of

mixing in B stars, but previous surveys have been biased towards

narrow-lined stars because of the difficulty in measuring boron

abundances in rapidly rotating stars. The two targets observed as part of

our Cycle 13 SNAP program 10175, just before STIS failed, demonstrate

that it is possible to make useful boron abundance measurements for

early-B stars with Vsin(i) above 100 km/s. We propose to extend that

survey to a large enough sample of stars to allow statistically

significant tests of models of rotational mixing in early-B stars.



STIS/CCD 11844



CCD Dark Monitor Part 1



Monitor the darks for the STIS CCD.



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 11852



STIS CCD Spectroscopic Flats C17



Obtain pixel-to-pixel lamp flat fields for the STIS CCD in spectroscopic

mode.



STIS/CCD/MA1/MA2 11690



EG And: Providing the Missing Link Required for Modelling Red Giant

Mass-Loss



For the majority of red giant stars the basic mass-loss processes at

work are unknown. Indeed, for stars of spectral types between K0 III and

M5-M6 III, much remains unknown about the regions above the visible

photosphere and the transportation of the processed material outwards to

the ISM. Eclipsing symbiotic binary systems, consisting of an evolved

giant in orbit with a white dwarf, provide an opportunity to take

advantage of the finite size of the hot component to probe different

levels of the chromosphere and wind acceleration region in absorption.

This provides spatially resolved thermal, ionisation and dynamic

information on the wind which can then be compared against predictions

of hydrodynamical stellar atmosphere codes. The symbiotic binary EG And

can be considered as a rosetta stone for understanding the winds of

these objects. The system is ideal on a number of counts for utilising

the ultraviolet eclipse of the white dwarf (WD) component to probe,

layer-by-layer, the thermal and dynamic conditions at the very base of

the wind and chromosphere of the RG. This information is vital for

constraining, testing and calibrating the new generation of cool giant

wind+chromosphere models and is not possible to obtain for isolated RGs.

This team has studied the UV eclipses of this system in depth and

detail, however in order to definitively constrain the wind acceleration

profile and identify the location of the temperature rise just above the

photosphere we require 4 STIS E140M observations of EG And at specific

orbital phases. We are also requesting a E230M observation of an

isolated spectral standard, corresponding to the RG in the binary, which

will help place the EG And results into the context of the general RG

population from analysis of the MgII wind diagnostic lines.



WFC3 11428



D2 Calibration Lamp Test



This proposal verifies the health and performance of the calsystem

deuterium lamp and assesses the status of the major UV filters by taking

a full set of internal flatfields. A total of three nominal and one

short exposure are obtained for each filter in order to establish an

initial baseline of flatfield data as well as to confirm lamp

repeatability and provide a contamination check. Additional iterations

of D2 internal flatfields will be taken as part of WFC-19, UVIS Internal

Flats (proposal 11432).



This proposal corresponds to SMOV ID WFC3-15. It should not be run until

after the successful completion of WFC-06, the UVIS detector functional

test (proposal 11419) and WFC-11, the initial UVIS alignment (proposal

11424).



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



WFC3/ACS/UVI 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/IR 11915



IR Internal Flat Fields



This program is the same as 11433 (SMOV) and depends on the completion

of the IR initial alignment (program 11425). This version contains three

instances of 37 internal orbits; to be scheduled early, middle, and near

the end of Cycle 17, in order to use the entire 110-orbit allocation.



In this test, we will study the stability and structure of the IR

channel flat field images through all filter elements in the WFC3-IR

channel. Flats will be monitored, i.e. to capture any temporal trends in

the flat fields, and delta flats produced. High signal observations will

provide a map of the pixel-to-pixel flat field structure, as well as

identify the positions of any dust particles.



WFC3/IR 11937



IR Grism Wavelength Calibration



This program will determine the wavelength calibration for the IR G102

and G141 grisms as a function of spatial position within the field of

view. The planetary nebula Vy2-2 will be observed in a 9-point pattern

in the IR field of view, which will provide FoV-dependent dispersion

maps for the G102 and G141 grisms.



WFC3/UVI 11656



A Comprehensive Survey of Neptune's Small Moons and Faint Rings



We will use a subarray of the WFC3/UVIS to study the inner rings, arcs

and moons of Neptune with a sensitivity that exceeds that achieved by

any previous observations, including Voyager 2 during its 1989 flyby.

Our study will reveal any inner moons down to V magnitude 25,

corresponding to a radius ~ 20 km (assuming 9% albedo), to address a

peculiar, apparent truncation in the size distribution of inner moons

and to look for the "shepherds" and source bodies for Neptune's dusty

rings. (For comparison, the radius of Neptune's smallest known regular

moon, Naiad, is ~ 33 km.) Monitoring of the arcs at fine resolution and

sensitivity will reveal their ongoing evolution more clearly and will

enable us to assess the role of Galatea, whose resonant perturbations

are widely believed to confine the arcs. Our study will also reveal any

broad, faint rings with optical depth ~ 10^-6, comparable to those now

known to encircle all of the other giant planets.



WFC3/UVI 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 (11909), will be

used to generate the necessary superbias and superdark reference files

for the calibration pipeline (CDBS).



WFC3/UVI 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.



FLIGHT OPERATIONS SUMMARY:



Significant Spacecraft Anomalies: (The following are preliminary reports

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



HSTARS:

11985 - GSAcq(1,2,1) scheduled at 231/08:19:50 - 08:27:01 had resulted

in fine lock backup (2,0,2) using FGS-2 due to (QF1STOPF) stop flag

indication on FGS-1.



Observations possibly affected, STIS 42 Proposal ID# 11567.



COMPLETED OPS REQUEST: (None)



COMPLETED OPS NOTES: (None)



SCHEDULED SUCCESSFUL

FGS GSAcq 7 7

FGS REAcq 8 8

OBAD with Maneuver 8 8



SIGNIFICANT EVENTS: (None)