Featured Research

from universities, journals, and other organizations

Astronomers find 'lost' supernova

Date:
March 7, 2013
Source:
Harvard-Smithsonian Center for Astrophysics
Summary:
Supernova explosions of massive stars are common in spiral galaxies like the Milky Way, where new stars are forming all the time. They are almost never seen in elliptical galaxies where star formation has nearly ceased. As a result, astronomers were surprised to find a young-looking supernova in an old galaxy.

PS1-12sk PS1-12sk, the yellow dot at image center (circled), is classified as a very rare Type Ibn supernova - only the sixth such example found out of thousands of supernovae. It was discovered on the outskirts of a bright elliptical galaxy (the yellow blob to the upper left of the supernova) located about 780 million light-years from Earth. A Type Ibn supernova is thought to come from the explosion of a young, massive star. However, the site of the explosion shows no signs of recent star formation, and a supernova from a massive star has never before been seen in a galaxy of this type.
Credit: CfA / PS1 Science Consortium

The star Eta Carinae is ready to blow. 170 years ago, this 100-solar-mass object belched out several suns' worth of gas in an eruption that made it the second-brightest star after Sirius. That was just a precursor to the main event, since it will eventually go supernova.

Supernova explosions of massive stars are common in spiral galaxies like the Milky Way, where new stars are forming all the time. They are almost never seen in elliptical galaxies where star formation has nearly ceased. As a result, astronomers were surprised to find a young-looking supernova in an old galaxy. Supernova PS1-12sk, discovered with the Pan-STARRS telescope on Haleakala, is rare in more ways than one.

"This supernova is one-of-a-kind," said Nathan Sanders of the Harvard-Smithsonian Center for Astrophysics (CfA), lead author of the discovery paper. "And it's definitely in the wrong neighborhood."

Based on the presence of helium and other features, PS1-12sk is classified as a very rare Type Ibn supernova -- only the sixth such example found out of thousands of supernovae. Although the origin of this supernova type is unclear, the most likely cause seems to be the explosion of a massive star that previously ejected massive amounts of helium gas, much like Eta Carinae's Homunculus Nebula.

That origin was supported by the fact that the five previous Type Ibn supernovae were all found in galaxies like the Milky Way that are actively forming stars. (Since massive stars don't live long, they don't stray far from where they are born before exploding.)

PS1-12sk is different. It was found on the outskirts of a bright elliptical galaxy located about 780 million light-years from Earth. The site of the explosion shows no signs of recent star formation, and a supernova from a massive star has never before been seen in a galaxy of this type.

"It could be that we simply got very lucky with this discovery. But luck favors the prepared," said second author Alicia Soderberg of the CfA.

The finding suggests that the host galaxy might be hiding a star factory, allowing it to form massive stars where none were expected. Alternatively, PS1-12sk might have an entirely different origin such as a collision of two white dwarfs, one of which was helium-rich.

"Is this a runaway star from another star formation site? Is it a very local bit of star formation? Is it a different way for such a supernova to occur? None of these seems very likely so we have a real puzzle," said co-author John Tonry (University of Hawaii Institute for Astronomy).

The research has been submitted for publication in The Astrophysical Journal.


Story Source:

The above story is based on materials provided by Harvard-Smithsonian Center for Astrophysics. Note: Materials may be edited for content and length.


Cite This Page:

Harvard-Smithsonian Center for Astrophysics. "Astronomers find 'lost' supernova." ScienceDaily. ScienceDaily, 7 March 2013. <www.sciencedaily.com/releases/2013/03/130307161634.htm>.
Harvard-Smithsonian Center for Astrophysics. (2013, March 7). Astronomers find 'lost' supernova. ScienceDaily. Retrieved April 23, 2014 from www.sciencedaily.com/releases/2013/03/130307161634.htm
Harvard-Smithsonian Center for Astrophysics. "Astronomers find 'lost' supernova." ScienceDaily. www.sciencedaily.com/releases/2013/03/130307161634.htm (accessed April 23, 2014).

Share This



More Space & Time News

Wednesday, April 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Nuclear-Level Asteroids Might Be More Common Than We Realize

Nuclear-Level Asteroids Might Be More Common Than We Realize

Newsy (Apr. 23, 2014) The B612 Foundation says asteroids strike Earth much more often than previously thought, and are hoping to build an early warning system. Video provided by Newsy
Powered by NewsLook.com
NASA Chief Outlines Plan for Human Mission to Mars

NASA Chief Outlines Plan for Human Mission to Mars

AFP (Apr. 22, 2014) NASA administrator Charles Bolden, speaking at the 'Human to Mars Summit' in Washington, says that learning more about the Red Planet can help answer the 'fundamental question' of 'life beyond Earth'. Duration: 00:48 Video provided by AFP
Powered by NewsLook.com
Nasa Gives You An Excuse to Post a Selfie on Earth Day

Nasa Gives You An Excuse to Post a Selfie on Earth Day

TheStreet (Apr. 22, 2014) NASA is inviting all social media users to take a selfie of themselves alongside nature and to post it to Twitter, Facebook, Flickr, Instagram, or Google Plus with the hashtag #globalselfie. NASA's goal is to crowd-source a collection of snapshots of the earth, ground-up, that will be used to create one "unique mosaic of the Blue Marble." This image will be available to all in May. Since this is probably one of the few times posting a selfie to Twitter won't be embarrassing, we suggest you give it a go for a good cause. Video provided by TheStreet
Powered by NewsLook.com
SpaceX's Dragon Spacecraft Captured by International Space Station

SpaceX's Dragon Spacecraft Captured by International Space Station

Reuters - US Online Video (Apr. 20, 2014) SpaceX's unmanned Dragon spacecraft makes a scheduled Easter Sunday rendezvous with the International Space Station. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins