Quote:
|
Originally Posted by IMO
Quote:
|
Originally Posted by George
Quote:
|
Originally Posted by Minbari
Lawrence Berkeley National Lab's Saul Perlmutter
And
Brian Schmidt of Australia's Mount Stromlo and Siding Spring Observatories
|
No. The first announcement of acceleration was by another team. |
I though Perlmutter's Supernova Cosmology Project was first, follwed shortly by Schmidt's High-Z SN Search group. |
It was February 26th, 1998 (or the 27th). Alex Filippenko (CfA High Z team) spoke at the UCLA Dark Matter meeting. "Alex said clearly that our supernovae provided evidence that cosmic expansion
had sped up during the last 5 billion years" said Robert Kirshner in his marvelous book -
the Extravagant Universe.
This was before Saul Perlmutter's team news, though they had 40 supernova to CfA's 27 (14 of CfA plus 13 from Calan/Tololo).
The difference that gave the CfA team the edge, assuming I understand it, was their implentation of MLCS (
multicolor light-curve shape). Using mulitiple color filters helped them deal with issues such as dust. Hence the reason I asked the colorful question in the first place. Sort of a pattern I seemed stuck on lately :-? .
This greatly reduced their scatter from 40% to 15% which is a great advantage in improving the Gaussian sigma value. As I understand, it improves it as a squared value (about 9 in this case).
Of course, they did many other things to help their program including swimming in the shallow end of the pool (using Kirshner's analogy for nearby supernova) instead of the deep end. Learning to pull out Type 1b SN, knowing the brighter Type Ia dim slower than the weaker Type Ia, etc. were certainly major factors, too. However, these did not involve color so I consider them secondary. :wink:
[I feel obliged to enhance everyones appreciation for color in order to awakedn your interest in - The
Quest for the Color of the Sun!
] [Not really, but I have enjoyed the mild frolic
]
CfA ~ Center for Astronomics at Harvard, IIRC.