Status Report

NASA Hubble Space Telescope Daily Report #4824

By SpaceRef Editor
April 2, 2009
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Continuing to collect World Class Science

PERIOD COVERED: 5am April 1 – 5am April 2, 2009 (DOY 091/0900z-092/0900z)


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.


Significant Spacecraft Anomalies: (The following are preliminary reports of potential non-nominal performance that will be investigated.)


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.



                        SCHEDULED      SUCCESSFUL

FGS GSAcq               04                  02
FGS REAcq               10                  09
OBAD with Maneuver      28                  28


SpaceRef staff editor.