was getting groggy. It was 2 a.m. in the control room on top of
Hawaiis dormant volcano Mauna Kea, where he and a team of astronomers
were operating a special infrared camera with one of the worlds
largest telescopes, the Keck II. The late hour and oxygen-thin airat
14,000 feet above sea levelwere making him tired, so the scientist
had settled back to rest while a colleague from NASAs Jet Propulsion
Laboratory began searching for the next star on their list, unimaginatively
named HR 4796.
the 10-million-year-old object seemed to have disappeared when viewed
at mid-infrared wavelengths. With his colleague growing exasperated,
Koerner perked up and wondered if the object were more elongated
than they thought; he made a few adjustments to the instrument.
Suddenly, from 220 light years away, in the constellation Centaurus,
an unexpected image appeared on the computer screen.
been staring at it the whole time, says Koerner, now an assistant
professor of physics and astronomy at Penn. We thought we couldnt
even see the star. Next thing, we found a star with a disk around
it. We went ballistic.
ran into the kitchen to rouse the others from their break. Almost
immediately, they noticed that the dust- and gas-filled disk was
brighter on the ends than in the center. That seemed strange. We
were saying, Wow, does that thing have a big hole in it? It did,
in factan empty region 100 astronomical units (A.U.) in diameter,
just larger than our own solar system. (One A.U. equals the distance
from the Earth to the Sun.) What they were looking at was likely
a hole that had been cleared out by planets forming.
went out and walked around the mountain to try to slow the adrenaline,
recalls Koerner. And I remember thinking, Oh no, this is going
to be a real stressful ride.
Illustration by Anastasia Vasilakis