compiled by Bryan Hubbard
NASA’S Chandra Finds Fastest Wind from Stellar-Mass Black Hole
Published: Tuesday, February 21, 2012 – 16:33 in Astronomy & Space
Astronomers using NASA’s Chandra X-ray Observatory have clocked the fastest wind yet discovered blowing off a disk around a stellar-mass black hole. This result has important implications for understanding how this type of black hole behaves. The record-breaking wind is moving about 20 million mph, or about 3 percent of the speed of light. This is nearly 10 times faster than had ever been seen from a stellar-mass black hole.
Stellar-mass black holes are born when extremely massive stars collapse. They typically weigh between five and 10 times the mass of the Sun. The stellar-mass black hole powering this super wind is known as IGR J17091-3624, or IGR J17091 for short.
For the full story go to – Fastest wind from stellar-mass black hole
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.
For the full story go to – Saturn-Like Ring System
Discovery of the Smallest Exoplanets: The Barnard’s Star Connection
Published: Wednesday, January 11, 2012 – 17:36 in Astronomy & Space
The discovery of the three smallest planets yet orbiting a distant star, which was announced January 11 at the annual meeting of the American Astronomical Society, has an unusual connection to Barnard’s star, one of the Sun’s nearest neighbors. The discovery was made by a scientific team led by astronomers at the California Institute of Technology (Caltech) that included three members from Vanderbilt. The team used data from NASA’s Kepler mission combined with additional observations of a single star, called KOI-961, to determine that it possesses three planets that range in size from 0.57 to 0.78 times the radius of Earth. This makes them the smallest of the more than 700 exoplanets confirmed to orbit other stars.
In their investigation of KOI-961, which is about 130 light years away in the Cygnus constellation, the astronomers found that it is nearly identical to Barnard’s star, which is only six light years away in the constellation Ophiuchus. This similarity allowed them to use information about Barnard’s star, which was discovered in 1916 by Vanderbilt astronomer E.E. Barnard, to determine the mass, size and luminosity of the distant star. These values, in turn, were used to determine the size of the three new exoplanets.
For the full story go to – The Barnard’s star connection
UCLA Astronomers Solve Mystery of Vanishing Electrons
Published: Sunday, January 29, 2012 – 17:31 in Astronomy & Space
UCLA researchers have explained the puzzling disappearing act of energetic electrons in Earth’s outer radiation belt, using data collected from a fleet of orbiting spacecraft. In a paper published Jan. 29 in the advance online edition of the journal Nature Physics, the team shows that the missing electrons are swept away from the planet by a tide of solar wind particles during periods of heightened solar activity.
“This is an important milestone in understanding Earth’s space environment,” said lead study author Drew Turner, an assistant researcher in the UCLA Department of Earth and Space Sciences and a member of UCLA’s Institute for Geophysics and Planetary Physics (IGPP). “We are one step closer towards understanding and predicting space weather phenomena.”
The complete article may be found at Vanishing Electrons