On Wed, 22 Oct 2008 21:42:28 +0000 (UTC),
(Steve Willner) wrote:

In article ,
"WG" writes:
Is there an online catalogue for supernovas which lists data?

See http://supernova.lbl.gov/Union/

If I have this right, the distance determined by light curves
[supernova as standard candles], differs from distance determined
by redshift [hubbles law] by a significant amount. This difference
I believe was the reason why dark energy was postulated and
currently accepted.

That's a bit confusing, but I think you are on the right track. The
two distances differ _if you don't include dark energy_ in Hubble's
Law. If you do include dark energy, the redshift distance and the
standard candle distance agree just fine, and the amount of dark
energy is consistent with other data (such as microwave background
fluctuations). You might want to take a look at
http://www.astro.ucla.edu/~wright/sne_cosmology.html

Maybe you can clarify the logic. The y-axis is cz which boldly goes to
900000km/s. At z = 1 recession velocity is c. The light would be
invisible. Isn't it a fact that v = cz is limited to very small values
of z?
If I have z =1 then WL is lengthened by 1+z, the frequency by 1/1+z or
f' = f/1+z = f/2.
I fail to see how they continue the abcissa to 900,000 km/s for I
suppose z = 3, and then plot the ordinate as 12 Gpsc.
I would appreciate clarification.
John Polasek