HUBBLE SPACE TELESCOPE - Continuing to Collect World Class Science



DAILY REPORT #4932



PERIOD COVERED: 5am September 16 - 5am September 17, 2009 (DOY 259/09:00z-260/09:00z)



OBSERVATIONS SCHEDULED



ACS/WFC3 11879



CCD Daily Monitor (Part 1)



This program comprises basic tests for measuring the read noise and dark

current of the ACS WFC and for tracking the growth of hot pixels. The

recorded frames are used to create bias and dark reference images for

science data reduction and calibration. This program will be executed

four days per week (Mon, Wed, Fri, Sun) for the duration of Cycle 17. To

facilitate scheduling, this program is split into three proposals. This

proposal covers 352 orbits (22 weeks) from 31 August 2009 to 31 January

2010.



COS/FUV 11997



FUV Internal/External Wavelength Scale Monitor



This program monitors the offsets between the wavelength scale set by

the internal wavecal versus that defined by absorption lines in external

targets. This is accomplished by observing two external targets in the

SMC: SK191 with G130M and G160M and Cl* NGC 330 ROB B37 with G140L

(SK191 is too bright to be observed with G140L). The cenwaves observed

in this program are a subset of the ones used during Cycle 17. Observing

all cenwaves would require a considerably larger number of orbits.

Constraints on scheduling of each target are placed so that each target

is observed once every ~2-3 months. Observing the two targets every

month would also require a considerably larger number of orbits.



COS/NUV 11896



NUV Spectroscopic Sensitivity Monitoring



The purpose of this proposal is to monitor sensitivity of each NUV

grating mode to detect any changes due to contamination or other causes.



COS/NUV/FUV 11673



Dynamics in the Atmosphere of the Evaporating Planet HD189733b



With HST/STIS, we detected and characterized the upper atmosphere of the

extrasolar planet HD209458b, showing that the planet must be evaporating

at a rate of ~10^10 g/s in a "blow-off" mechanism.



More recently, using ACS we concluded that HD189733b is also

evaporating. However, because of the low resolution of the ACS prism

spectroscopy, the escape rate and mechanism are still to be determined.

This is one of the prime objectives of the present proposal.



COS observations of the absorption line profile with 15 km/s resolution

will allow us to probe the dynamics of the escaping gas, and therefore

to determine the escape rate. Simultaneous observations of the transit

depth and spectral shape in several important lines (not only HI, but

also OI, CII and possibly NI) will constrain the escape mechanism and

allow us to distinguish between several scenarios. The results will

enlighten the physical phenomenons at work in the exosphere of these

extrasolar planets, and provide new constraints for the modeling of the

evaporation of hot-Jupiters.



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 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.



WFC3/ACS/IR 11600



Star Formation, Extinction, and Metallicity at 0.7<z<1.5: H-Alpha Fluxes

and Sizes from a Grism Survey of GOODS-N



The global star formation rate (SFR) is ~10x higher at z=1 than today.

This could be due to drastically elevated SFR in some fraction of

galaxies, such as mergers with central bursts, or a higher SFR across

the board. Either means that the conditions in z=1 star forming galaxies

could be quite different from local objects. The next step beyond

measuring the global SFR is to determine the dependence of SFR,

obscuration, metallicity, and size of the star-forming region on galaxy

mass and redshift. However, SFR indicators at z=1 typically apply local

calibrations for UV, [O II] and far-IR, and do not agree with each other

on a galaxy-by-galaxy basis. Extinction, metallicity, and dust

properties cause uncontrolled offsets in SFR calibrations. The great

missing link is Balmer H-alpha, the most sensitive probe of SFR. We

propose a slitless WFC3/G141 IR grism survey of GOODS-N, at 2

orbits/pointing. It will detect Ha+[N II] emission from 0.7<z<1.5, to

L(Ha) = 1.7 x 10^41 erg/sec at z=1, measuring H-alpha fluxes and sizes

for > 600 galaxies, and a small number of higher-redshift emitters. This

will produce: an emission-line redshift survey unbiased by magnitude and

color selection; star formation rates as a function of galaxy

properties, e.g. stellar mass and morphology/mergers measured by ACS;

comparisons of SFRs from H-alpha to UV and far-IR indicators;

calibrations of line ratios of H-alpha to important nebular lines such

as [O II] and H-beta, measuring variations in metallicity and extinction

and their effect on SFR estimates; and the first measurement of scale

lengths of the H-alpha emitting, star-forming region in a large sample

of z~1 sources.



WFC3/UVIS 11650



Mutual Orbits, Colors, Masses, and Bulk Densities of 3 Cold Classical

Trans-Neptunian Binaries



Many Trans-Neptunian Objects (TNOs) have been found to be binary or

multiple systems. As in other astrophysical settings, Trans-Neptunian

Binaries (TNBs) offer uniquely valuable information. Their mutual orbits

allow the direct determination of their system masses, perhaps the most

fundamental physical quantity of any astronomical object. Their

frequency of occurrence and dynamical characteristics provide clues to

formation conditions and evolution scenarios affecting both the binaries

and their single neighbors. Combining masses with sizes, bulk densities

can be measured. Densities constrain bulk composition and internal

structure, key clues to TNO origins and evolution over time. Several TNB

bulk densities have been determined, hinting at interesting trends. But

none of them belongs to the Cold Classical sub- population, the one

group of TNOs with demonstrably distinct physical characteristics. Two

top-priority Spitzer programs will soon observe and measure the sizes of

3 Cold Classical TNBs. This proposal seeks to determine the mutual

orbits and thus masses of these systems, enabling computation of their

densities.



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 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: (None)



COMPLETED OPS REQUEST: (None)



COMPLETED OPS NOTES: (None)



SCHEDULED SUCCESSFUL

FGS GSAcq 9 9

FGS REAcq 8 8

OBAD with Maneuver 8 8



SIGNIFICANT EVENTS: (None)


David Cottle

UBB Owner & Administrator