The super-massive black hole at the center of the Milky Way Galaxy has a healthy appetite, frequently snacking on asteroids and comets. Now, a cloud of gas and dust called G2 is on a dangerous course to become its next meal.
Even though Sagittarius A* (pronounced “Sagittarius A-star”) hasn’t been easy to see through the cosmic dust, sitting 25,000 light years away at galaxy central, scientists know it is a black hole — and a hungry one at that. Its weight has been estimated to be more than that of 4 million suns. (more…)
Discovery crucial to revealing fabric of space and time around black hole
UCLA astronomers report the discovery of a remarkable star that orbits the enormous black hole at the center of our Milky Way galaxy in a blistering 11-and-a-half years — the shortest known orbit of any star near this black hole.(more…)
Astronomers have witnessed for the first time a spiral galaxy in the early universe, billions of years before many other spiral galaxies formed. In findings reported July 19 in the journal Nature, the astronomers said they discovered it while using the Hubble Space Telescope to take pictures of about 300 very distant galaxies in the early universe and to study their properties. This distant spiral galaxy is being observed as it existed roughly three billion years after the Big Bang, and light from this part of the universe has been traveling to Earth for about 10.7 billion years.
“As you go back in time to the early universe, galaxies look really strange, clumpy and irregular, not symmetric,” said Alice Shapley, a UCLA associate professor of physics and astronomy, and co-author of the study. “The vast majority of old galaxies look like train wrecks. Our first thought was, why is this one so different, and so beautiful?” (more…)
PASADENA, Calif. – Astronomers using data from NASA’s Kepler mission have discovered the three smallest planets yet detected orbiting a star beyond our sun. The planets orbit a single star, called KOI-961, and are 0.78, 0.73 and 0.57 times the radius of Earth. The smallest is about the size of Mars.
All three planets are thought to be rocky like Earth but orbit close to their star, making them too hot to be in the habitable zone, which is the region where liquid water could exist. Of the more than 700 planets confirmed to orbit other stars, called exoplanets, only a handful are known to be rocky. (more…)
An international team of astronomers has identified for the first time a thick stellar disc in the Andromeda galaxy, the nearest large spiral galaxy to our own Milky Way.
The discovery of the thick disc, a major result from a five-year investigation, will help astronomers better understand the processes involved in the formation and evolution of large spiral galaxies like ours, according to the team, which includes UCLA research astronomer Michael Rich and colleagues from Europe and Australia.(more…)
Astronomers detected the faint signature of small, dim red dwarf stars in nearby galaxies (right), and found they are much more numerous than in our own Milky Way (left). Image credit: Patrick Lynch/Yale University
Astronomers have discovered that small, dim stars known as red dwarfs are much more prolific than previously thought — so much so that the total number of stars in the universe is likely three times bigger than previously believed.
Because red dwarfs are relatively small and dim compared to stars like our Sun, astronomers hadn’t been able to detect them in galaxies other than our own Milky Way and its nearest neighbors before now. Therefore, they did not know how much of the total stellar population of the universe is made up of red dwarfs.
Now astronomers have used powerful instruments on the Keck Observatory in Hawaii to detect the faint signature of red dwarfs in eight massive, relatively nearby galaxies called elliptical galaxies, which are located between about 50 million and 300 million light years away. They discovered that the red dwarfs, which are only between 10% and 20% as massive as the Sun, were much more bountiful than expected. (more…)
