"I saw a star move that wasn't supposed to," says Paul Green, talking about
one of his most important discoveries.
"It doesn't sound like much to you, I suppose," he says excitedly. "Let
me explain."
Green was looking at carbon giants. These are very bright stars that are
so far away from Earth that they seem faint.
"These stars are really, really far away," says Green. "A hundred thousand
light-years away."
Like most other days, Green wasn't at the telescope for this discovery.
He took a picture of the star and compared its position with a photo taken
of the same star 40 years earlier. "It had changed position," says Green.
"That was the big surprise."
Green was surprised because the further away an object is, the faster and
further it has to travel in order to appear to be moving. A plane doesn't
appear to be moving as fast as a car that zips past you on the street. In
fact the plane is moving 10 to 15 times faster than the car. Because the plane
is further away from you, it appears to be moving more slowly.
That's why Green couldn't believe what he saw. It was impossible for any
object to move so quickly.
"The star had to be nearby in order to see it move," says Green. But if
a carbon giant star were nearby, it would be much brighter.
"That meant I wasn't looking at a carbon giant at all," he says.
Green had discovered a whole new class of stars: stars that are nearby
but are faint. He called them carbon dwarfs.
"After that, I found a whole bunch more," he says. Now many other astronomers
are researching this type of star.
"A lot of other people jumped on the bandwagon," says Green.
Green continues to study carbon stars. "There are 100 or 1,000 things that
interest me in astronomy," he says. "This just happens to be a field that
has problems I can solve using the current technology."
Matthew Ashby, an astronomer in Massachusetts, has been interested in astronomy
since he was three years old.
His dad bought him his first telescope when he was in high
school. "I was looking for Halley's comet and I happened to see the moons
of Jupiter," he says. "It was the first time that I discovered something alone
and it was a wonderful experience."
Ashby began his college career studying English, but couldn't resist his
love of the stars and switched to the sciences. He studied black holes during
graduate school.
But the job isn't always enjoyable. Astronomy has plenty of difficult moments
-- and many tedious ones.
"I spend two weeks at the telescope and the rest of the year at my computer,"
says Green.
The most difficult part of Ashby's job was finding it. "The job situation
is fairly difficult right now," he says. "I feel very lucky to be doing the
work I am. It's rewarding to think about the big questions in life."
For astronomy professor Anne Cowley, the problem is paperwork and bureaucracy
that can get in the way of her research.
"The endless unimportant paperwork within a university is totally frustrating,"
she says. "You have to fill out a form for everything."
Yet the job is so exciting that the positives far outweigh the negatives.
Cowley says finding the answers to the great questions is a thrill. "It is
great fun finding answers to problems people haven't understood previously,"
she says.
The huge size of the universe is one of the questions that fascinates Green.
"There's just nothing bigger than outer space," he says. "I've always been
fascinated with that."
Astronomy helps us put our lives in perspective, he adds. "Each day we
rediscover that we're just one very small part of the cosmos."