Four dead planetary systems, each lit by the burned-out core of a star that once resembled the sun, provide a harrowing forecast for Earth’s eventual demise.
Astronomers used the space-based Hubble telescope to probe the chemical signatures of dusty disks encircling the four star systems. In each they found a surprising abundance of elements that make up about 93 percent of Earth’s mass.
“What we are seeing today in these white dwarfs several hundred light years away could well be a snapshot of the very distant future of the Earth,” said Boris Gänsicke, an astrophysicist at the University of Warwick, in a press release.
Images: Three panels illustrate the death sequence of a planetary system. Four terrestrial planets orbit a sun-like star (top); the host star turns into a red giant and mixes up planetary orbits, causing them to collide (middle); dusty debris and asteroid-like objects are all that remains around the star, now a white dwarf (bottom). (Copyright of Mark A. Garlick/University of Warwick) [high resolution]
Great Venus Setting
Bright Venus setting between Taurus and Auriga. A star filter was used in the camera lens to create the spikes, no special post-processing.
Photographed by Luis Argerich
Black holes get fat on tasty, tasty stars
We already know that black holes swallow stars — and entire solar systems — but what effect does a stellar diet have on black holes? A new study suggests that eating stars is what turns baby black holes into supermassive black holes.
These awesome photos of the night sky were all captured by Ben Canales.
Subaru’s eye improvesThe instrument atop Mauna Kea, Hawaii, improves its optics by a factor of 10.(November 21, 2006)
An image of the trapezium region in the Orion Nebula with and without adaptive optics. The image on the right has a resolution of 0.6 arcseconds and was obtained with Subaru’s CISCO camera in 1999 without the use of adaptive optics. The image on the left has a resolution of 0.06 arcseconds and was obtained in October 2006 using Subaru’s IRCS camera and the new adaptive optics system.
Star ends infancy abruptlyAstronomers using the Subaru Telescope have observed a young star maturing.(October 2006)Zooming in on a nearby young star called HD 141569A, astronomers from the National Astronomical Observatory of Japan and the Max Planck Institute for Astronomy used the Subaru telescope on Mauna Kea, Hawaii, to discover a hole in a disk of gas and dust encircling the star. The existence of this large gap, which is about the size of the orbit of Saturn, supports the theory that this young star ended its infancy abruptly, by ionizing and pushing away the gas in the disk from which it was born.Emission from carbon monoxide (CO) in the disk surrounding HD 141569A, which lies some 320 light-years away from Earth, extends out to a distance fifty times the size of the orbit of Earth. (The distance between Earth and the Sun is called an astronomical unit. In our solar system, the orbital radius of Neptune is about 30 AU). It gradually becomes stronger toward the inner part closest to the star. The emission peaks at around 15 AU, then diminishes to the central star. “We now know that little gas remains in the inner 11 AU of the disk,” said Usuda. “In other words, HD 141569A has fully developed a hole at the center of its molecular gas disk bigger than the size of the orbit of Saturn.” (continue reading)