News:
The Nobel Prize in Physics 2011 was divided, one half awarded to Saul Perlmutter, the other half jointly to Brian P. Schmidt and Adam G. Riess "for the discovery of the accelerating expansion of the Universe through observations of distant supernovae".
On Sunday May 10th,
I received a telephone call from Herb Knapp our club's observatory director.
Herb was very excited to report that a new supernova in M96 was discovered
by Mirko Villi. This prompted me to look at several images I had taken of
M96 on May 2, 1998.
Brian Skiff at the Lowell Observatory confirmed that my pre-discovery images did in fact capture the SN, and he offered to submit the details to the appropriate agencies and the IAU. Brian's estimates that the SN was at mag 16.5 +/- 0.3 on May 3.14 UT. Hopefully, the data from my image can help with the analysis and classification of SN1998bu.
The following is excerpt from Science Magazine's July 2, 1999 edition:
A team of astronomers says it has found slight, previously unnoticed variations among the exploding stars called type Ia supernovae. These explosions, thought to flare up to roughly the same brightness each time, have served the crucial role of cosmic "standard candles" whose apparent brightness, as seen from Earth, can serve as a measure of their distance. Unexplained variations in the explosions could, in theory, call into question the cosmic measurements based on them--among them the dramatic finding that the expansion rate of the universe is speeding up over time (see Science, 18 December 1998, p. 2156).
The discrepancies emerged when Adam Riess,
Alexei Filippenko, and Weidong Li of the University of California, Berkeley,
and Brian Schmidt of Mount Stromlo and Siding Spring Observatory in Australia
looked closely at the early phase of 10 nearby type Ia explosions. The
team found that the time it took the explosions to reach their peak brightness
was more than 2 days longer than the average for supernovae billions of
light-years away as measured by a second group. "They're pretty strongly
discrepant with one another," says Riess of the two data sets. "If it's
true, it's extremely interesting," says Eddie Baron, an astrophysicist
at the University of Oklahoma, Norman, who saw Riess's presentation at
a workshop in Aspen,
Colorado, on 17 June.
Type Ia supernovae are prized as distance indicators not only because they seem to explode in nearly the same way each time, but also because astronomers can account for leftover brightness differences. Studies of supernovae at the same distance have shown that the rise and fall of brightness, which unfolds over several months, takes longer for slightly brighter explosions. But because the explosions are generally not spotted until they are well under way, astronomers had never examined in detail the interval between a supernova's appearance and its peak.
Now, Riess and his colleagues have filled
that gap by drawing on a robotic telescope that Filippenko and others operate,
as well as on observations by a team of supernova watchers at the Beijing
Astronomical Observatory and by
amateurs. Indeed, Riess says that Chuck
Faranda, an amateur astronomer from Florida, spotted the freshest explosion
using an electronic camera hooked to a small telescope in his back yard.
The Supernova Cosmology Project, whose analysis was led by Berkeley's Gerson
Goldhaber, relied on surveys of many galaxies to spot large numbers of
distant supernovae, catching some of them early in their history (James
Glanz).
Click this link to see
Update: July 2007, see Astronomy's September 2007 (pg 34-39) for the latest info and details of Riess' research in to dark matter. Read the papers here and here
Update: February 2010, see Astronomy Magazine February 2010
pg.30
for additional references to expansion and dark matter/energy related to
SN1998bu