Berkeley researchers provide “roadmap” and tools for finding and studying Type Ia supernovae in their natural habitat
Type Ia supernovae are indispensable milestones for measuring the expansion of the universe. With definitive measures of Supernova 2011fe, the same “Backyard Supernova” that thrilled amateur and professional astronomers alike in the summer of 2011, the Nearby Supernova Factory led by Lawrence Berkeley National Laboratory demonstrates that this unusually close-by Type Ia is such a perfect example of its kind that future Type Ia’s – and models meant to explain their physics – must be measured against it.
The Palomar Transient Factory (PTF) brings together universities, observatories, and one national laboratory to hunt for supernovae and other astronomical objects. At the National Energy Research Scientific Computing Center (NERSC) Berkeley Lab processes and stores the data from PTF’s surveys, which use the Oschin Telescope at Caltech’s Palomar Observatory. On August 25, 2010, PTF’s “autonomous
In 2004 the Supernova Cosmology Project used the Hubble Space Telescope to find a tantalizing supernova that appeared to be almost 10 billion light-years distant. But Berkeley Lab scientists had to wait until a new camera was installed on the Hubble years later before they could confirm the candidate’s identity and redshift as a Type Ia “standard candle.” The spectrum and light curve of supernova SCP-0401 are now known with clarity; it is the supernova furthest back in time that can be used for precise measurements of the expansion history of the universe.
The multi-institutional Palomar Transient Factory (PTF) team presents the first-ever direct observations of a Type 1a supernova progenitor system. Astronomers have collected evidence indicating that the progenitor system of a Type 1a supernova, called PTF 11kx, contains a red giant star. They also show that the system previously underwent at least one much smaller nova eruption before it ended its life in a destructive supernova.
Even as the “supernova of a generation” came into view in backyards across the northern hemisphere last August, physicists and astronomers who had caught its earliest moments were developing a surprising and much clearer picture of what happens during a titanic Type Ia explosion. Now they have announced the closest, most detailed look ever at one of the universe’s brightest “standard candles,” the celestial mileposts that led to the discovery of dark energy.
Saul Perlmutter of Lawrence Berkeley National Laboratory’s Physics Division and the University of California at Berkeley has won the 2011 Nobel Prize in Physics for the discovery of the accelerating expansion of the universe through observations of distant supernovae. Perlmutter, a founder of the Supernova Cosmology Project at Berkeley Lab, shares the prize with Brian Schmidt and Adam Riess, members of the High-z Supernova Search Team who made the same discovery.
The Supernova Cosmology Project’s Union2 compilation and reanalysis of decades of the world’s best supernova surveys, with the addition of six high-redshift supernovae, puts new bounds on possible values for the nature of dark energy. Einstein’s cosmological constant comfortably fits the data, but there’s still plenty of room at the top for dynamical theories.
Members of the Nearby Supernova Factory based at Berkeley Lab discovered and analyzed a rare Type Ia supernova whose progenitor star had a mass some two and a half times that of our sun – much more mass than a Type Ia progenitor should be able to accumulate before it explodes. The data they gathered is the most complete ever for such an unusual beast; only one model really fits, the merger of two white dwarf stars.