Wolf-Rayet stars, more than 20 times as massive as the Sun and at least five times as hot, are relatively rare and often obscured. Scientists don’t know much about how they form, live and die.
The Baryon Oscillation Spectroscopic Survey (BOSS) pioneered the use of quasars to chart the universe’s expansion and investigate the properties of dark energy through studies of large-scale structure. New techniques of analysis led by Berkeley Lab scientists, combined with other new BOSS quasar measures of the young universe’s structure, have produced the most precise measurement of expansion since galaxies formed.
Until recently, scientists thought they knew why Type Ia supernovae – the best cosmological “standard candles” – are all so much alike. But their favorite scenario was wrong. White dwarfs don’t all reach the Chandrasekhar limit, 1.4 times the mass of our sun, before they detonate in a massive thermonuclear explosion. Most Type Ia progenitors are less massive, and a few are even more massive. New work by the Berkeley Lab-based Nearby Supernova Factory can identify which theories of the strange circumstances that lead to a Type Ia explosion actually work and which don’t.
The Baryon Oscillation Spectroscopic Survey (BOSS), the largest component of the third Sloan Digital Sky Survey, has measured the clustering of nearly 1.3 million galaxies spectroscopically to determine the “standard ruler” of the universe’s large-scale structure to within one percent, the most precise such measurement ever made.
The Baryon Oscillation Spectroscopic Survey (BOSS), the largest component of the third Sloan Digital Sky Survey, has measured the clustering of nearly 1.3 million galaxies spectroscopically to determine the “standard ruler” of the universe’s large-scale structure to within one percent. This is the most precise such measurement ever made and is likely to establish the standard for years to come.
New results from IceCube, the neutrino observatory buried at the South Pole, may show the way to locating and identifying cosmic accelerators in our galaxy that are 40 million times more powerful than the Large Hadron Collider at CERN.
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.
At a March 21 NASA telephone news conference, scientists from the U.S. team participating in the European Space Agency’s Planck mission to map the cosmic microwave background (CMB) discussed Planck’s first cosmological results, including some surprising news. For one thing, the universe is 13.82 billion years old, a hundred million years older than previously thought,
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