January 7, 2013 |
NASA's NuSTAR X-ray telescope is providing fresh views of oddly bright black holes and breathtaking supernovae, scientists said Monday at the American Astronomical Society meeting in Long Beach. NuSTAR mission scientists released high-energy X-ray images of two strangely bright black holes in the arms of spiral galaxy IC 342 about 7 million light years away and of Cassiopeia A, the shell of an exploded star, known as a supernova, just 11,000 light years away. Since its launch last summer , the Nuclear Spectroscopic Telescope Array has been snapping shots at energies up to 79 kiloelectron volts - far beyond the roughly 10 KeV limit of other X-ray telescopes such as the Chandra X-Ray Observatory.
November 2, 2012 |
Australian astronomers using a Hawaiian telescope have observed two so-called super-luminous supernovae, only the second and third such objects ever discovered. The new supernovae, 10 to 100 times brighter than conventional supernovas, are from the earliest stages of the universe and are thought to occur by a different mechanism, the researchers reported online Friday in the journal Nature. Conventional supernovae shine extremely brightly for several weeks or months, putting out more light than the entire galaxies they reside in. They typically have two causes: either the re-ignition of nuclear fusion in a degenerate star or the collapse of the core of a massive aging star.
August 24, 2012 |
Astronomers have for the first time observed a nova-producing system turn into a supernova, a finding that indicates the universe has more than one way to create a nova. A normal Type Ia supernova is a rare event, occurring perhaps once or twice every century. The type of supernova observed by a team of astronomers led by astronomer Ben Dilday of UC Santa Barbara is estimated to occur about one time in every 1,000 supernovae. The findings are important because supernovae are generally all considered to have the same intrinsic brightness, making them what astronomers call "standard candles" used for estimating distances across the cosmos.
January 14, 2012 |
Type 1a supernovae, exploding stars that can outshine entire galaxies, were instrumental to the Nobel Prize-winning discovery that a mysterious "dark energy" is fueling the expansion of the universe. But astronomers haven't been able to pin down what causes these massive stellar explosions. Now, after studying a Type 1a supernova in a nearby galaxy, two researchers say that they must be the result of a collision between two white dwarf stars. They made their case this week in the journal Nature.
October 11, 2011
Neutrinos: An Oct. 4 Op-Ed about controversial neutrino research findings described an earlier experiment in which neutrinos and light from a supernova traveled at the same speed. The Op-Ed said that if the controversial findings were correct, the neutrinos in the earlier experiment would have been detected four years after the visual signal from the supernova. It should have said the neutrinos would have been detected four years before the visual signal. Patt Asks : In Patt Morrison's Oct. 8 interview, Carl Djerassi's late wife was misidentified as Diane Middleton.
June 8, 2011 |
A team led by Caltech astronomers has discovered a new type of supernova that may burn 100 times brighter than typical exploding stars — and they're trying to figure out exactly how this new type works. The study, which identified four newly discovered supernovae as part of this unknown class, also solves the mystery behind two previously unexplained events — one that had been thought to be an extremely luminous Type II supernova, and another whose nature had scientists completely baffled.