Perhaps some sense of proportion is needed here. The latest
ain't necessarily the greatest in any of man's endeavors, folks,
and one must always remember that in cosmology there's one more
fact to keep in mind at all times: almost all cosmological
publications are wrong in some important way (in the sense that
they do not stand the test of time).
I haven't seen the article either, but in October this preprint*
appeared at xxx.lanl.gov. Schmidt is one of the authors, and the
subject is right on, so this is likely an earlier report on the
same work:
astro- ph/ 9710123 13 Oct 1997
"Constraints on Cosmological Models from Hubble Space Telescope
Observations of High-z Supernovae" by Peter M. Garnavich,
Robert P. Kirshner, Peter Challis, John Tonry, Ron L. Gilliland,
R. Chris Smith, Alejandro Clocchiatti, Alan Diercks,
Alexei V. Filippenko, Mario Hamuy, Craig J. Hogan, B. Leibundgut,
M.M. Phillips, David Reiss, Adam G. Riess, Brian P. Schmidt,
J. Spyromilio, Christopher Stubbs, Nicholas B. Suntzeff, and
Lisa Wells
I don't know how the order of authors was determined, but there
are some heavy hitters in that list. They would have to be to
get target of opportunity Hubble time, of course, which is what
they have done here. The SNe are discovered on ground-based
equipment and Hubble then does precision photometry on them. The
trick is to get on them as soon as possible after discovery, The
shape of the light curve being a very important identifier of
what kind of a SN has been discovered.
This paper argues marginally for a cosmological constant based
upon Hubble observations of three very distant supernovae, only
two of which can be identified as of Type Ia and therefore can
be considered to be "typical" and relied upon as "standard
candles" for measuring distance by means of the inverse square
law. The Science paper likely pertains to the same data, perhaps
expanded by additional Hubble SNe.
If I had to guess about whether these guys got their sign wrong
*or* the universe is decelerating under gravity, I might get
romantic and get excited, too. If I had to bet more than two
bits on it, however, I'd go the other way. More data are needed
before the conventional picture, an expanding decelerating
universe, is abandoned. Determining the deceleration parameter
was a principle mission for Hubble; there will be more data in
a relatively short time.