Cosmic Matters Blog » Science News
Dec 22, 2010
Humans are not alone in their struggle against an increasing waistline. Astronomers believe that galaxies too put on weight throughout their lives, growing not only by consuming hydrogen gas—which is then converted to stars—but also by cannibalizing other galaxies. It’s a galaxy-eat-galaxy cosmos, but the big surprise is that many galaxies seem to be growing to even larger sizes than their eating habits would suggest.
The gluttonous galaxies in question are known, perhaps not surprisingly, as “ellipticals.” Their three-dimensional form distinguishes them from disk-like galaxies, including slim and beautiful spirals like M51 and our own Milky Way. Ellipticals have long been known to be, well, fat.
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Jul 15, 2010
Astronomers using Keck Observatory have identified the first known quasar acting as a gravitational lens that magnifies an even more distant galaxy. The discovery may provide astronomers with a new technique to study quasars.
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Jun 15, 2010
Astronomers using both 10-meter Keck telescopes together have peered deep into swirling clouds of gas and dust that will eventually become planetary systems like the Solar system. The team studied 15 young Milky Way stars and observed proto-planetary disk material within 0.1 astronomical units, or nine million miles, of the target star.
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May 26, 2010
Astrophysicists using the Keck Observatory have identified two white dwarf stars in an eclipsing binary system, allowing for the first direct radius measurement of a rare white dwarf composed of pure helium.
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May 19, 2010
New data from several telescopes, including the W. M. Keck Observatory, suggest astronomers may have identified a new type of supernovae. The stellar death is thought to have originated in a star that was a low-mass white dwarf accumulating helium from a companion star. When the white dwarf exploded, about half of the mass ejected from the supernova was in the form of calcium.
The finding suggests that a couple of supernovae like this exploding every 100 years would produce the high abundance of calcium observed in galaxies like the Milky Way, and the calcium present in life on Earth.
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Apr 5, 2010
On a clear, crisp evening, Geoff Marcy will walk outside and gaze up at the San Francisco night sky where he lives. He looks at the stars, but his mind is on the millions or even billions of planets that may orbit them. The distant worlds are so far away that they cannot be seen with the naked eye, but Marcy knows they exist. He can imagine them circling their stars.
Like most people, he wonders whether any of those distant worlds are like Earth. Yet, unlike most people, he has access to the world’s best telescopes, including Keck Observatory, to help answer this question. Marcy has led the way in discovering planets of all types beyond our Solar System, including super-hot orbs larger than Jupiter and icy balls similar in size to Neptune. With Keck, he and his fellow astronomers recently found distant worlds not much larger than Earth orbiting stars similar to our Sun. Such a discovery leads Marcy to believe that within the next few years, they will find the “holy grail” of planet hunting—another Earth.
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