Friday, October 21, 2011

Birth of Youngest Planet Ever Seen Is Witnessed With Telescopic Trick

Protoplanetary Disk The image at left shows a 
transitional disk around the star LkCa 15. All of the
light at this wavelength is emitted by cold dust in the 
disk. The hole in the center indicates an inner gap 
with radius of about 55 times the distance from the 
Earth to the Sun. The image at right shows a 
expanded view of the cleared region, seen in two 
wavelengths. The star shape marks the location of 
LkCa 15, which has been blotted out so the disk 
can be seen. Kraus & Ireland/via Keck Observatory

Astronomers have captured the first direct image of a newly forming planet orbiting around its star, using mirrors to blot out the star’s blinding light. The LkCa 15 system contains a hot, coalescing world sitting in a gap between the star and an outer disk of dust, exactly in accord with most theories of how planets are born.

The discovery is a triumph for exoplanet hunters and for unique telescope techniques, as researchers combined adaptive optics with a light-masking method to block starlight. Previously, planetary formation has been impossible to see directly, because it happens very close to the star and the disk is washed out.

Adam Kraus of the University of Hawaii and Michael Ireland from Macquarie University and the Australian Astronomical Observatory worked with the twin 10-meter Keck telescopes on Mauna Kea in Hawaii, scanning 150 stars containing protoplanetary disks. LkCa 15 was only their second target, but they knew pretty quickly it was a good one, according to a news release from the W.M. Keck Observatory.                   More