Closest Type Ia supernova in decades solves a cosmic mystery
Published: Wednesday, December 14, 2011 – 15:33 in Astronomy & Space
Type Ia supernovae (SN Ia’s) are the extraordinarily bright and remarkably similar “standard candles” astronomers use to measure cosmic growth, a technique that in 1998 led to the discovery of dark energy — and 13 years later to a Nobel Prize, “for the discovery of the accelerating expansion of the universe.” The light from thousands of SN Ia’s has been studied, but until now their physics — how they detonate and what the star systems that produce them actually look like before they explode — has been educated guesswork……On August 24 of last year, searching data as it poured into DOE’s National Energy Research Scientific Computing Center (NERSC) from an automated telescope on Palomar Mountain in California, Nugent spotted a remarkable object. It was shortly confirmed as a Type Ia supernova in the Pinwheel Galaxy, some 21 million light-years distant. That’s unusually close by cosmic standards, and the nearest SN Ia since 1986; it was subsequently given the official name SN 2011fe.
For the full story go to – Cosmic Mystery
Some nearby young stars may be much older than previously thought
Published: Wednesday, December 21, 2011 – 15:37 in Astronomy & Space
Low in the south in the summer sky shines the constellation Scorpius and the bright, red supergiant star Antares. Many of the brightest stars in Scorpius, and hundreds of its fainter stars, are among the youngest stars found near Earth, and a new analysis of them may result in a rethinking of both their ages and the ages of other groups of stars. New research by astrophysicists from the University of Rochester focused on stars in the north part of the constellation, known as Upper Scorpius, which is a part of the Scorpius-Centaurus OB association, one of our best studied groups of young stars and a benchmark sample for investigating the early lives of stars and the evolution of their planet-spawning disks. The Upper Scorpius stellar group lies roughly 470 light years from Earth.
While those stars have been thought to be just five million years old, the team concludes that those stars are actually more than twice as old, at 11 million years of age. The findings are surprising given Upper Scorpius’s status as one of the best-studied samples of young stars in the sky.
For the full story go to – Stars may be much older than previously thought
Scientists discover a Saturn-like ring system eclipsing a sun-like star
Published: Wednesday, January 11, 2012 – 14:35 in Astronomy & Space
A team of astrophysicists from the University of Rochester and Europe has discovered a ring system in the constellation Centaurus that invites comparisons to Saturn. The scientists, led by Assistant Professor of Physics and Astronomy Eric Mamajek of Rochester and the Cerro Tololo Inter-American Observatory, used data from the international SuperWASP (Wide Angle Search for Planets) and All Sky Automated Survey (ASAS) project to study the light curves of young Sun-like stars in the Scorpius-Centaurus association — the nearest region of recent massive star formation to the Sun.
The basic concept of the research is straightforward. Imagine yourself sitting in a park on a sunny afternoon and a softball passes between you and the sun. The intensity of light from the sun would appear to weaken for just a moment. Then a bird then flies by, causing the intensity of the sunlight to again weaken — more or less than it did for the baseball, depending on the size of the bird and how long it took to pass. That’s the principle that allowed the researchers to discover a cosmic ring system.
The complete article may be found at A saturn ring system eclipsing a sun star