HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

 

DAILY REPORT      # 4303

 

PERIOD COVERED: UT February 20, 2007 (DOY 051)

 

OBSERVATIONS SCHEDULED

 

ACS/SBC 10862

 

Comprehensive Auroral Imaging of Jupiter and Saturn during the

International Heliophysical Year

 

A comprehensive set of observations of the auroral emissions from

Jupiter and Saturn is proposed for the International Heliophysical Year

in 2007, a unique period of especially concentrated measurements of

space physics phenomena throughout the solar system. We propose to

determine the physical relationship of the various auroral processes at

Jupiter and Saturn with conditions in the solar wind at each planet.

This can be accomplished with campaigns of observations, with a sampling

interval not to exceed one day, covering at least one solar rotation.

The solar wind plasma density approaching Jupiter will be measured by

the New Horizons spacecraft, and a separate campaign near opposition in

May 2007 will determine the effect of large-scale variations in the

interplanetary magnetic field {IMF} on the Jovian aurora by

extrapolation from near-Earth solar wind measurements. A similar Saturn

campaign near opposition in Jan. 2007 will combine extrapolated solar

wind data with measurements from a wide range of locations within the

Saturn magnetosphere by Cassini. In the course of making these

observations, it will be possible to fully map the auroral footprints of

Io and the other satellites to determine both the local magnetic field

geometry and the controlling factors in the electromagnetic interaction

of each satellite with the corotating magnetic field and plasma density.

Also in the course of making these observations, the auroral emission

properties will be compared with the properties of the near-IR

ionospheric emissions {from ground-based observations} and non thermal

radio emissions, from ground-based observations for Jupiter?s decametric

radiation and Cassini plasma wave measurements of the Saturn Kilometric

Radiation {SKR}.

 

ACS/SBC 11048

 

SBC MAMA Recovery

 

Procedure to be used when ACS MAMA anomalously shuts down. Recovery

procedure is designed to carefully bring the MAMA back to operating

condition while watching for possible problems. The final step is to do

a fold analysis which gives detailed information about how well the

instrument is performing. Only the first four visits are to be executed.

Visits 5 to 7 whih are a repaeat of 1 to 4 are to be kept on hold.

 

NIC1 10879

 

A search for planetary-mass companions to the nearest L dwarfs -

completing the survey

 

We propose to extend the most sensitive survey yet undertaken for very

low-mass companions to ultracool dwarfs. We will use NICMOS to complete

imaging of an all-sky sample of 87 L dwarfs in 80 systems within 20

parsecs of the Sun. The combination of infrared imaging and proximity

allows us to search for companions with mass ratios q>0.25 at

separations exceeding ~3 AU, while probing companions with q>0.5 at ~1.5

AU separation. This resolution is crucial, since no ultracool binaries

are known in the field with separations exceeding 15 AU. Fifty L dwarfs

from the 20-parsec sample have high- resolution imaging, primarily

through our Cycle 13 HST proposal which identified six new binaries,

including an L/T system. Here, we propose to target the remaining 30

dwarfs

 

NIC1/NIC2/NIC3 11060

 

NICMOS Photometric Stability Monitoring

 

This NICMOS calibration proposal carries out photometric monitoring

observations during Cycle 15. The format is the same as the Cycle 14

version of the program {10725}, but a few modifications were made with

respect to the Cycle 12 program 9995 and Cycle 13 program 10381.

Provisions had to be made to adopt to 2-gyro mode {G191B2B was added as

extra target to provide target visibility through most of the year}.

Where before 4 or 7 dithers were made in a filter before we moved to the

next filter, now we observe all filters at one position before moving to

the next dither position. While the previous method was chosen to

minimize the effect of persistence, we now realize that persistence may

be connected to charge trapping and by moving through the filter such

that the count rate increases, we reach equilibrium more quickly between

charge being trapped and released. We have also increased exposure times

where possible to reduce the charge trapping non- linearity effects.

 

NIC1/NIC2/NIC3 8794

 

NICMOS Post-SAA calibration - CR Persistence Part 5

 

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, ACS/WFC 10802

 

SHOES-Supernovae, HO, for the Equation of State of Dark energy

 

The present uncertainty in the value of the Hubble constant {resulting

in an uncertainty in Omega_M} and the paucity of Type Ia supernovae at

redshifts exceeding 1 are now the leading obstacles to determining the

nature of dark energy. We propose a single, integrated set of

observations for Cycle 15 that will provide a 40% improvement in

constraints on dark energy. This program will observe known Cepheids in

six reliable hosts of Type Ia supernovae with NICMOS, reducing the

uncertainty in H_0 by a factor of two because of the smaller dispersion

along the instability strip, the diminished extinction, and the weaker

metallicity dependence in the infrared. In parallel with ACS, at the

same time the NICMOS observations are underway, we will discover and

follow a sample of Type Ia supernovae at z > 1. Together, these

measurements, along with prior constraints from WMAP, will provide a

great improvement in HST's ability to distinguish between a static,

cosmological constant and dynamical dark energy. The Hubble Space

Telescope is the only instrument in the world that can make these IR

measurements of Cepheids beyond the Local Group, and it is the only

telescope in the world that can be used to find and follow supernovae at

z > 1. Our program exploits both of these unique capabilities of HST to

learn more about one of the greatest mysteries in science.

 

NIC3 10899

 

Identifying z>7 galaxies from J-dropouts

 

NICMOS Parallel Imaging campaigns covered enough sky {250 pointings}

with enough sensitivity in the 110W and 160W filters to identify 6

extremely red resolved sources which are prime candidates for J-band

dropouts. Their complete absence of detectable J band flux can be caused

by an opaque Lyman cut-off at z=8-10. We propose to followup these

candidates with NICMOS imaging and jointly propose Spitzer IRAC

photometry. Deep F110W and Spitzer/IRAC 3.5/4.8 micron imaging will

confirm if any of these candidates are indeed Lyman Break galaxies

observed less than 500 Myrs after the Big Bang. Genuine LBGs will remain

undetected in F110W, while being detected with flat spectra in the IRAC

bands. The combined SED will provide information about the stellar mass

of these galaxies, and the possible presence of evolved stars or dust

reddening. The proposed observations will be sensitive enough to detect

the F110W flux from galaxies as red as {J- H}=2.8 {AB mags, 5 sigma}. If

any of the candidates are detected with bluer colors, they will most

likely be exceptional "Distant Red Galaxies" at z of 4 to 6. The

proposed data will constrain the stellar populations of these

extraordinarily red galaxies, which would be candidates for the

earliest, most massive galaxies which formed.

 

WFPC2 10871

 

Observations of the Galilean Satellites in Support of the New Horizons

Flyby

 

On February 28 2007 the New Horizons {NH} spacecraft will fly by Jupiter

on its way to Pluto, and will conduct an extensive series of

observations of the Jupiter system, including the Galilean satellites.

We propose HST observations to support and complement the New Horizons

observations in four ways: 1} Determine the distribution and variability

of Io's plumes in the two weeks before NH closest approach, to look for

correlations with Io- derived dust streams that may be detected by New

Horizons, to understand the origin of the dust streams; 2} Imaging of

SO2 and S2 gas absorption in Io's plumes in Jupiter transit, which

cannot be done by NH; 3} Color imaging of Io's surface to determine the

effects of the plumes and volcanos seen by New Horizons on the surface-

New Horizons cannot image the sunlit surface in color due to saturation;

4} Imaging of far-UV auroral emissions from the atmospheres of Io,

Europa, and Ganymede in Jupiter eclipse, near- simultaneously with

disk-integrated NH UV spectra, to locate the source of the UV emissions

seen by NH and use the response of the satellite atmospheres to the

eclipse to constrain production mechanisms.

 

WFPC2 11029

 

WFPC2 CYCLE 15 Intflat Linearity Check and Filter Rotation Anomaly

Monitor

 

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 xxxx 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.

 

WFPC2 11092

 

Hubble Heritage Observations of Arp 87

 

The Hubble Heritage team will use a single pointing of WFPC2 to obtain

F450W, F555W, F656N, and F814W images of Arp 87 as part of a public

release image.

 

FLIGHT OPERATIONS SUMMARY:

 

Significant Spacecraft Anomalies: (The following are preliminary reports

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

 

HSTARS:

10703 - GSAcq (1,2,2) failed due to Search Radius Limit Exceeded on FGS 2

   At 051/10:12:54 GSAcq (1,2,2) scheduled from 051/10:09:22-10:16:41

   failed due to search radius limit exceeded on FGS 2. Received one (1)

   486 ESB 1808 (TxG FHST Sanity Check Failed) and one (1) a05 (Exceeded

   SRL).

   OBAD #1 RSS: 1422.72 a-s

   OBAD #2 RSS: 7.12 a-s

   OBAD MAP RSS: 16.08 a-s

 

10704 - REAcqs(1,2,2) failed to RGA Hold (Gyro Control)

   Upon acquisition of signal, the REAcq(1,2,2) scheduled at 051/11:43:48

   had failed to RGA Hold due to search radius limit exceeded on FGS2.

   Pre-reacq OBADs (RSS) values not available due to LOS.

 

COMPLETED OPS REQUEST: (None)

 

COMPLETED OPS NOTES: (None)

 

                      SCHEDULED      SUCCESSFUL     

FGS GSacq               09                  08               

FGS REacq               05                  03              

OBAD with Maneuver 27                  27               

 

SIGNIFICANT EVENTS:

Flash Report: SBC - preliminary results

The first SBC images (science and calibration) were acquired today (Day

051). All the telemetry indicates normal conditions. The first internal

flats and dark frames are consistent with those pre-dating the ACS Side

2 failure. There may be a small degradation in sensitivity (on the order

of 1% or less at the shortest wavelengths). More sensitivity data will

be acquired in the coming week.