On November 7, 2008, 14-year-old Caroline Moore of Warwick, New York, discovered a supernova in the galaxy UGC 12682, making her the youngest person ever to find an exploding star. She made the discovery in an image taken by a 16-inch Meade LX200 telescope in Arizona that is part of the Puckett Observatory World Supernova Search, led by amateur astronomer Tim Puckett.

The supernova remnant of Cassiopeia A, as seen through the Spitzer Space Telescope.

Intern B (Valerie Daum)

The peculiar object, designated Supernova 2008ha, has turned out to be the weakest supernova on record. It was about a thousand times more powerful than a nova (a nuclear explosion on the surface of an old, compact star called a white dwarf), but a thousand times weaker than a typical supernova (the cataclysmic explosion of an entire star).

"Supernova 2008ha was a really wimpy explosion," says Alex Filippenko (University of California, Berkeley), a leading expert on exploding stars.

The supernova appeared relatively faint for the host galaxy's 70-million-light-year distance, leading astronomers to initially think that it was either a supernova dimmed by a lot of interstellar dust or a “supernova impostor,” an eruption on the surface of a massive star that appears similar to a supernova.

On November 18th, Ryan Foley (Harvard-Smithsonian Center for Astrophysics) and his team obtained the first spectrum of SN 2008ha. It was odd, and did not immediately yield a classification. Eventually, Foley found it was very similar to another peculiar supernova, SN 2002cx, but it had a much lower expansion velocity. SN 2002cx itself had a very lower expansion velocity, meaning that SN 2008ha ejected material with much less energy than most supernovae. It showed no significant dimming due to interstellar dust, leading Foley to conclude that it was an extremely weak supernova.

"You can imagine many ways for a star to explode that might resemble SN 2008ha," says Robert Kirshner (also at the Harvard-Smithsonian Center for Astrophysics). "It could have been a massive star suddenly collapsing to form a black hole, with very little energy leaking out. But it looks a lot like its brighter cousins [Type Ia supernovae], which we think are nuclear explosion of white dwarfs. Maybe this one was an explosion of that general type, just much, much weaker."

Foley finds the spectral analysis particularly interesting. In most supernovae, the high velocity of the ejecta smears out many spectral features into one big feature, making it difficult to determine chemical composition. "With SN 2008ha, the velocity was low enough that individual features could be separated, showing us exactly what the supernova was made of,” says Foley.

Explosions of this kind may not have been seen before because of their inherent dimness. A new generation of telescopes and instruments is beginning to search greater distances than ever before, effectively monitoring millions of galaxies. But as Moore’s discovery shows, an attentive human eye is far from obsolete.

Valerie Daum is an intern at Sky and Telescope

Comments


Image of Brian Breshears

Brian Breshears

June 12, 2009 at 9:56 am

It would be nice to know a bit more about Miss Moore, the astronomer that found the supernova. Not a simple task by a long shot! What kind of telescope, camera, how long has she been doing astronomy, how long has she been involved in the supernova search? Great information on the supernova but the headline makes me want to know more about a young lady astronomer and how she managed to find a supernova when many of us are struggling to even get clear images of Jupiter! Outstanding accomplishment!

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Alexandru Burda

June 12, 2009 at 11:41 am

I must agree with Brian. It would have been very interesting to know a little more about the young discoverer, Miss Moore. As I understand from the article, she was not just lucky. She did some valuable scientific work to find the supernova.

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Mario Quiroz Treguer

June 12, 2009 at 11:26 pm

A couple of months ago, I attended to a lecture about Supernovas, I found a very interesting subject, since then I´d been studying more about it. So it´s so great that a teen as Miss Moore could discover such wimpy supernova.
I´m curios too wanting to know what kind of telescope and camera she used to achieve such a remarkable fact. My congratulations Caroline.

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Pete from north central Mass

June 13, 2009 at 4:11 am

I have to agree with the comments above, and to add that Miss Moore shows a skill needed by all astronomers. If her observation abilities were measured (I scored 91st percentile in direct observation in a a comprehensive aptitude test I took once), I am sure she would score real high. I think we have a budding astronomer in the making here. You're young enough to steer toward a major, tuning up your math skills, heading toward physics. Good find.

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William

June 13, 2009 at 5:17 am

Why is this story just making news now, 7 months after the discovery? It would have been nice to read about it November or December. But June? Apart from the wimpiness, which needed additional study, it would have been nice to feature Miss Moore's discovery and a profile of her back then -- not wait until June.

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Len

June 13, 2009 at 9:23 am

I agree, here's a little more information on Miss Moore - http://www.recordonline.com/apps/pbcs.dll/article?AID=/20081123/NEWS/811230324/-1/NEWS

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Len

June 13, 2009 at 9:25 am

I agree, here's more information on Miss Moore - http://www.recordonline.com/apps/pbcs.dll/article?AID=/20081123/NEWS/811230324/-1/NEWS

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Jack Hettinger

June 14, 2009 at 8:48 am

I agree with all the comments that much more information about Caroline Moore should have been provided. Thanks to Len for sharing that site about her. Also the expression "wimpiest supernova" disappoints me: it sounds like a putdown when Moore did a terrific job in spotting the phenomenon that so many others missed. A small supernova but a huge achievement.

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Jack Hettinger

June 14, 2009 at 8:48 am

I agree with all the comments that much more information about Caroline Moore should have been provided. Thanks to Len for sharing that site about her. Also the expression "wimpiest supernova" disappoints me: it sounds like a putdown when Moore did a terrific job in spotting the phenomenon that so many others missed. A small supernova but a huge achievement.

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Mark Sabo

June 14, 2009 at 9:59 am

Quite a story, not timely on S&T's part though.
Plenty of info & pictures here:

http://deer-pond-observatorie.wetpaint.com/page/The+story+about+SN2008ha

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Nathaniel Sailor

June 22, 2009 at 7:54 pm

Lucky! She got a picture of a supernova. Well good for her that's great. But mom and dad haves a lot of money so she could get that stuff. Plus the skies I have to work with sucks. It's light polluted and I don't have filters. And I want to more about the object series UGC. E-mail. [email protected]

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