Another interesting story from this interview:
We all know "telescope time" is the single most precious item for professional astronomers. When you applied for a time slot in any of the large telescopes, you need to write a very good proposal, outlining the purposes of your observation, its goals, etc, etc. This proposal will then be "refereed" by your peers. Even if you finally get the time slot, it may be several months. Moreover, you seldom have control on "when" you can have the telescope time.
Another well know fact: The discovery of a supernova is deemed purely accidental. No one can predict if he can find a Sn, not to say "when"!
Both Perlmutter and Reiss came up with a novel idea to get telescope time slots. In their proposals, they would put down, for the purposes, " ...to observe in details the spectra of about 10-15 SN's TO BE DISCOVERED NEXT WEEK...."
No observatory director would reject such request, if and only if you can "guarantee" such discovery.
How they did this? The answer is not that complicated: On average, a SN will appear in a galaxy about every ~300 years (or 100,000 days). If we can take the image of 100,000 galaxies a night, we would discover at least one SN. Thus, the 2 teams make use of the few nights before and after new moon to take VERY DEEP field images, in the areas far away from interstellar dust. As a result, they routinely found 10-15 SN a month to fullfil their promise in the proposals. Perlmutter started such work in 1988 and, after 10 years of hard work, accomplished enough data to find the inflation of the universe. Reiss started similar work in 1994 and came to same result in 1998.
pts |
發表於 2011-10-4 23:08:17
發表於 2011-10-5 00:47:20
發表於 2011-10-8 00:43:50