HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

DAILY REPORT      #4824

PERIOD COVERED: 5am April 1 - 5am April 2, 2009 (DOY

                           091/0900z-092/0900z)

OBSERVATIONS SCHEDULED

WFPC2 11794

Cycle 16 Visible Earth Flats

This proposal monitors flatfield stability. This proposal obtains

sequences of Earth streak flats to construct high quality flat fields

for the WFPC2 filter set. These flat fields will allow mapping of the

OTA illumination pattern and will be used in conjunction with previous

internal and external flats to generate new pipeline superflats. These

Earth flats will complement the Earth flat data obtained during cycles

4-15.

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.

WFPC2 11944

Binaries at the Extremes of the H-R Diagram

We propose to use HST/Fine Guidance Sensor 1r to survey for binaries

among some of the most massive, least massive, and oldest stars in our

part of the Galaxy. FGS allows us to spatially resolve binary systems

that are too faint to observe using ground-based, speckle or optical

long baseline interferometry, and too close to resolve with AO. We

propose a SNAP-style program of single orbit FGS TRANS mode observations

of very massive stars in the cluster NGC 3603, luminous blue variables,

nearby low mass main sequence stars, cool subdwarf stars, and white

dwarfs. These observations will help us to (1) identify systems suitable

for follow up studies for mass determination, (2) study the role of

binaries in stellar birth and in advanced evolutionary states, (3)

explore the fundamental properties of stars near the main sequence-brown

dwarf boundary, (4) understand the role of binaries for X-ray bright

systems, (5) find binaries among ancient and nearby subdwarf stars, and

(6) help calibrate the white dwarf mass - radius relation.

WFPC2 11974

High-resolution Imaging for 9 Very Bright, Spectroscopically Confirmed,

Group-scale Lenses

There are large samples of strong lenses that probe small (galaxy) scale

masses (e.g., SLACS, SQLS, COSMOS). There are also large samples of

strong lenses that probe large (rich cluster) scale masses (e.g.,

various rich Abell clusters, the Hennawi et al. 2008 SDSS sample). The

sample of strong lenses that probe intermediate (group/cluster-core)

scale masses, however, is sparse, and so any significant additions to

this sample are important. Here we present a sample of strong lenses

that not only probe these intermediate scales but are also quite bright,

since the sample is based almost entirely upon data from the SDSS, a

relatively shallow and poor-resolution survey, at least in comparison to

most other strong lens hunting grounds, such as COSMOS and CFHTLS. What

we lack are the high-resolution imaging data needed to construct

detailed lensing models, to probe the mass and light profiles of the

lensing galaxies and their environments, and to characterize the

morphologies of the lensed (source) galaxies. Only HST can provide these

data, and so we are proposing here for 81 orbits of deep WFPC2 F450W,

F606W and F814W imaging, for 9 of our best and brightest

intermediate-scale lensing systems with known spectroscopic redshifts

and with Einstein radii between 4 and 8 arcsec.

WFPC2 11994

HST Participation in the IYA 100 Hours of Astronomy

As a leader in astronomical imaging and delivering Hubble science to the

world, the Office of Public Outreach at Space Telescope Science

Institute wishes to organize a Hubble Space Telescope participation in

the 2009 International Year of Astronomy (IYA) event entitled "100 Hours

of Astronomy." This cornerstone project, which will be held April 2 - 5,

2009, will bring together observers from all over the world to use and

look through telescopes to admire the heavens. We will have a public

voting session that will highlight six astronomical objects that have

never been viewed with Hubble. Objects have been preselected to fit in

the field of view of the WFPC2 camera, and that are observable during

the April viewing window. The voting session will close on March 1st,

2009, and the most popular candidate will be observed and released

during the "100 Hours of Astronomy" event. Observations will be made

with four filters for a composite press release image. We ask for eight

orbits of Hubble time from the Director's Discretionary pool of orbits.

This will allow a modest amount of S/N for the candidate that will be

selected. The archive science data products will become public at the

time of release.

FLIGHT OPERATIONS SUMMARY:

Significant Spacecraft Anomalies: (The following are preliminary reports

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

HSTARS:

11756 - GSAcq (2,1,2) @092/04:03:55z and REAcq @092/05:37:06z failed to RGA Hold.

           Observations affected: WFPC 99-102, Proposal ID# 11974

11757 - GSAcq (2,1,2) scheduled from 092/07:15:54 - 07:23:37 failed to RGA Hold due to

           QF2STOPF flag on FGS-2.

           Observations affected: WFPC 103-105, Proposal ID# 11974.

11758 - REAcq (2,1,2) scheduled from 092/08:49:01 - 08:56:44. resulted in

           Fine Lock Back-up (2,0,2).

           Observations possibly affected: WFPC 106-107, Proposal ID# 11974.

COMPLETED OPS REQUEST: (None)

COMPLETED OPS NOTES: (None)

                       SCHEDULED      SUCCESSFUL 

FGS GSAcq               04                  02    

FGS REAcq               10                  09 

OBAD with Maneuver 28                  28              

SIGNIFICANT EVENTS: (None)