This Echo is READ ONLY !   NO Un-Authorized Messages Please!
 ~~~~~~~~~~~~~~~~~~~~~~~~   ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

31 Mar 2003
HUBBLE SPACE TELESCOPE
DAILY REPORT # 3330
PERIOD COVERED: DOYs 87-89

Part 2 of 4

ACS 9420

Intensive Coverage of the Eta Carinae Event in 2003

For a variety of reasons, HST can provide a very special and unique
data set when Eta Car experiences its next spectroscopic event in
mid-2003. Explaining the phenomenon is only part of the motivation.
This star and its ejecta have unique characteristics that make them
important for several branches of astrophysics; and when a
spectroscopic event occurs, it's like varying the parameters in an
experiment {or rather, set of experiments}. The 2003 event will be
the last chance in the forseeable future to obtain such a data set.
Eta Carinae has extreme parameters; it is mysterious in surprisingly
basic ways; and HST/STIS can gather useful data on it at a terrific
rate. As we explain below, the proposed data set will be valuable in
several independent ways: It will help solve a specific set of
current problems, it will constitute a large and unique archival data
base for both stellar and nebular astrophysics, and it will be
well-suited for educational uses.

ACS 9352

The Deceleration Test from Treasury Type Ia Supernovae at Redshifts
1.2 to 1.6

Type Ia supernovae {SNe Ia} provide the only direct evidence for an 
accelerating universe, an extraordinary result that needs a rigorous
test. The case for cosmic acceleration rests on the observation that
SNe Ia at z ~ 0.5 are ~ 0.25 mag fainter than they would be in a
universe without acceleration. A powerful and straightforward way to
assess the reliability of the SN Ia measurement and the conceptual
framework of its interpretation is to look for cosmic deceleration at
z >= 1. This would be a clear signature of a mixed dark-matter and
dark-energy universe. Systematic errors in the SN Ia result
attributed to grey dust or cosmic evolution of the SN Ia peak
luminosity would not show this change of sign. We have demonstrated
proof of this concept with a single SN Ia, SN 1997ff at z = 1.7,
found and followed by HST. The results suggest an early epoch of
deceleration, but this is too important a conclusion to rest on just
one object. Here we propose to use HST for observations of six SNe Ia
in the range 1.2 <= z <= 1.6, that will be discovered as a byproduct
from proposed Treasury programs for high-latitude ACS surveys. Six
objects will provide a much firmer foundation for a conclusion that
touches on important questions of fundamental physics.

ACS/WFC/HRC 9445

Gravitational Microlensing in the NGC 3314A-B Galaxy Pair.

The Advanced Camera for Surveys (WFC and HRC) was used to determine
the composition of the dark matter that dominates the masses of
galaxies which is an important unsolved problem.

ACS/WFPC2 9481

Pure Parallel Near-UV Observations with WFPC2 within High-Latitude
ACS Survey Fields

In anticipation of the allocation of ACS high-latitude imaging
survey{s}, we request a modification of the default pure parallel
program for those WFPC2 parallels that fall within the ACS survey
field. Rather than duplicate the red bands which will be done much
better with ACS, we propose to observe in the near-ultraviolet F300W
filter. These data will enable study of the rest-frame ultraviolet
morphology of galaxies at 0 * Origin: SpaceBase(tm) Pt 1 -14.4- Van BC Canada 604-473-9358 (1:153/719.1)

SEEN-BY: 633/267 270

@PATH: 153/719 715 7715 140/1 106/2000 633/267