View Full Version : Signs of young planets
2004-Aug-13, 04:26 PM
Sharpest Image Ever Obtained of a Circumstellar Disk Reveals Signs of Young Planets (http://www.spaceref.com/news/viewpr.html?pid=14812)
The sharpest image ever taken of a dust disk around another star has revealed structures in the disk which are signs of unseen planets.
Dr. Michael Liu, an astronomer at the University of Hawaii's Institute for Astronomy, has acquired high resolution images of the nearby star AU Microscopii (AU Mic) using the Keck II Telescope, the world's largest infrared telescope. At a distance of only 33 light years, AU Mic is the nearest star possessing a visible disk of dust. Such disks are believed to be the birthplaces of planets.
"We cannot yet directly image young planets around AU Mic, but they cannot completely hide from us either. They reveal themselves through their gravitational influence, forming patterns in the sea of dust grains orbiting the star," said Dr. Liu.
2004-Aug-13, 04:53 PM
I'll see what Steve has to say in a couple of months when AstroSoc starts up again. He's a postgrad working on exoplanet detection.
2004-Aug-13, 08:07 PM
The resulting infrared images are the sharpest ever obtained of a circumstellar disk, with an angular resolution of 1/25 of an arcsecond...
Is this for real? If so, I think it beats Hubble's and even with disadvantage of much greater wavelength to boot.
2007-Jan-08, 12:11 AM
New observations from NASA's Hubble Space Telescope have begun to fill gaps in the early stages of planet birth.
Hubble observed a "blizzard" of particles in a disk around a young star revealing the process by which planets grow from tiny dust grains. The particles are as fluffy as snowflakes and are roughly ten times larger than typical interstellar dust grains. They were detected in a disk encircling the 12-million-year-old star AU Microscopii. The star is 32 light-years away in the southern constellation of Microscopium, the Microscope.
The particles' fluffiness suggests that they were shed by much larger, but unseen snowball-sized objects that had gently collided with each other. These unseen objects are believed to reside in a region dubbed the "birth ring," first hypothesized in 2005 by Berkeley astronomers Linda Strubbe and Eugene Chiang. The ring is between 3.7 billion and 4.6 billion miles from the star. As the larger objects bump into each other, they release fluffy particles that are propelled outward by the intense pressure from starlight.
Read more (http://hubblesite.org/newscenter/archive/releases/2007/02/full/)
2007-Jan-09, 04:04 AM
A flurry of lint-like particles discovered swirling around a small, distant star could help explain how miniscule interstellar dust grains clump together to form planets, astronomers say.
"We have seen many seeds of planets and we have seen many planets, but how they go from one to the other is a mystery. These observations help us to fill in that gap" said study team member James Graham of the University of California, Berkeley.
The newfound fluffy particles are about ten times larger than interstellar dust grains and about as porous as newly fallen snow, which is composed of about 97% air and only 3% ice.
Read more (http://www.usatoday.com/tech/science/space/2007-01-08-space-lint_x.htm)
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