"An extraordinary outburst produced by a black hole in a nearby galaxy has provided direct evidence for a population of old, volatile stellar black holes. The discovery, made by astronomers using data from NASA's Chandra X-ray Observatory, provides new insight into the nature of a mysterious class of black holes that can produce as much energy in X-rays as a million suns radiate at all wavelengths.
Researchers used Chandra to discover a new ultraluminous X-ray source, or ULX. These objects give off more X-rays than most binary systems, in which a companion star orbits the remains of a collapsed star. These collapsed stars form either a dense core called a neutron star or a black hole. The extra X-ray emission suggests ULXs contain black holes that might be much more massive than the ones found elsewhere in our galaxy.
A paper describing these results will appear in the May 10, 2012, issue of The Astrophysical Journal."Source: NASA
The Caribbean islands are more than a tourist hot spot; they are also breeding grounds for some of the most diverse species of lizards, many of which are also on the verge of extinction, scientists say.
Twenty-four species of lizards, known as skinks and never before identified, slithered into the scientific textbooks this week.
“For all these years working in the Caribbean, I just assumed that these skinks had not evolved very much in this specific region. It’s a real surprise to find this diverse fauna of lizards,” said Blair Hedges, a Penn State University evolutionary biologist and lead author of the study identifying these previously unknown species of skinks.
Skinks have snakelike bodies with small, smooth and round scales, but they are different than most other reptiles because they have a lengthy gestational period like humans.
“There are other lizards that give live birth, but only skinks make a placenta and carry their offspring for up to one year,” Hedges said.