August 6, 2008

Dutch Teacher Discovers New Astronomy Object

Even though it was discovered by a Dutch primary school teacher it's not a fairytale, in fact, it's a "cosmic ghost" that could possibly represent a new class of astronomical objects.

While volunteering with the Galaxy Zoo project - which enlists the public to help classify galaxies online - the 25 year old teacher Hanny van Arkel, discovered the strange, gaseous object with a hole in the middle.

"At first, we had no idea what it was. It could have been in our solar system, or at the edge of the universe," Yale University astrophysicist Kevin Schawinski, a member and co-founder of the Galaxy Zoo team, said in a statement.

The discovery was nicknamed "Hanny's Voorwerp", which is Dutch for object. 

Soon after, astronomers confirmed that the object was one-of-a-kind. Details of the discovery appear in the journal Monthly Notices of the Royal Astronomical Society.

"What we saw was really a mystery," Schawinski said. "The Voorwerp didn't contain any stars."

It appeared the green object was made entirely of hot gas, and seems to be illuminated by remnant light from the nearby galaxy IC 2497.

"We think that in the recent past the galaxy IC 2497 hosted an enormously bright quasar," Schawinski said.

He said light from the past still illuminates the ghostly object, even though the quasar-a powerful radiation source powered by a supermassive black hole- shut down some 100,000 years ago.

 "It's this light echo that has been frozen in time for us to observe," said Chris Lintott, a co-organizer of Galaxy Zoo at Oxford University in the United Kingdom, said in a statement.

Researchers will get a closer look, when they use the Hubble Space Telescope.

"It's amazing to think that this object has been sitting in the archives for decades and that amateur volunteers can help by spotting things like this online," Van Arkel said in a statement.

Smaller light echoes have been noted around exploding stars, or supernovas, but never on this scale.

Dr. Lintott said the object was the only one of its type known to astronomers, though other Voorwerpen could still be awaiting identification. He said Mrs. Van Arkel brought the object to the attention of Galaxy Zoo members; she has no background in astronomy.

After failing to match the object to any galaxy types described in the Galaxy Zoo classification tutorial, she emailed the site's webmaster. This alerted team members who studied the images themselves.

Van Arkel is one of more than 150,000 amateur astronomers who have helped classify more than 1 million galaxies over the past year as part of the Galaxy Zoo project. During the next stage, the project will ask volunteers to search for more unusual astronomical objects.

Image Courtesy Dan Smith, Peter Herbert, Matt Jarvis & the ING


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