Planet-forming dust disc surrounding distant star disappears
July 5, 2012 - Los Angeles Times
A disc of planet-forming dust around a distant star has disappeared
unexpectedly, leaving astronomers scratching their heads and questioning
current theories of how planets are formed. "It's like the classic
magician's trick: Now you see it, now you don't," said astronomer Carl
Melis of UC San Diego, who led the team that discovered the phenomenon.
"Only in this case, we're talking about enough dust to fill an inner
solar system and it is really gone." The team has proposed several
possible explanations for the disappearance, but "none are really
compelling," Melis said.
...
The team reported Thursday in
the journal Nature that they reexamined the star in 2008 using the
Gemini South Observatory in Chile and found the same infrared signature
observed in 1983. But when they looked at it again in 2009 with NASA's
orbiting Wide-field Infrared Survey Explorer, about two-thirds of the
dust had disappeared....