Featured Research

from universities, journals, and other organizations

Astronomer unveils the mysteries of 'Green Pea' galaxies

Date:
September 12, 2010
Source:
Europlanet Media Centre
Summary:
First discovered in 2007 by amateur stargazers, the strange so-called Green Pea galaxies have now been shown to be extraordinary and extremely compact star cities that have low amounts of complex elements after being diluted by streams of gas and strong supernova winds.

The work of citizen scientists was invaluable in documenting Green Pea galaxies. Amateurs worked alongside professional astronomers to gather and analyse data.
Credit: Sloan Digital Sky Survey and Richard Nowell

First discovered in 2007 by amateur stargazers, the strange so-called Green Pea galaxies have now been shown to be extraordinary and extremely compact star cities that have low amounts of complex elements after being diluted by streams of gas and strong supernova winds.

Related Articles


Presenting at the Joint European and National Astronomy Meeting (JENAM2010), lead scientist Ricardo Amorin said: "This Green Pea discovery is a fabulous example of how normal citizens, 'astronomy lovers', can help scientists with their collective efforts. They discuss the science with professional astronomers, and have written an excellent Wikipedia entry about Green Pea galaxies which presents a lot of information to people of the world."

Green Pea galaxies were first classified by hobby stargazers. The online project Galaxy Zoo and Galaxy Zoo 2 asked interested members of the public to help sort through a vast depository of night sky images produced by the Sloan Digital Sky Survey. Categorising galaxy types is both important to learn about the evolution of the Universe, and also difficult because of the ambiguous shape of many. Astronomers turned to the online community for help, and citizen scientists flocked to sift through the images and look for galaxy types. Within 24 hours of launch the site was receiving an astonishing 70,000 classifications an hour.

These citizen scientists discovered a strange type of galaxy that did not fit with previously known types. Small in size and green in colour, they were soon named "Green Pea" galaxies. They appear to be compact low-mass galaxies undergoing intense star formation, and being around 1.5 to 5 billion years distant indicates that this is a brief but extreme stage of their evolution.

Green Pea galaxies are now known to be "metal-poor"; metals in this astronomical sense meaning any element other than hydrogen and helium. The study presented today suggests that gas gravitationally attracted from the outskirts of the Green Pea galaxies or beyond, combined with shockwaves from supernova explosions, are likely causes. Amorin explains: "Discovering Green Pea galaxies has opened a new window to investigate galaxy evolution and star formation in the early Universe."

Green Pea galaxies aren't the only citizen science successes to come from Galaxy Zoo. In 2007, Dutch school teacher Hanny van Arkel was categorising galaxies for the project when she came across a very strange object. This was soon named Hanny's Voorwerp, from the Dutch for "Hanny's Object." This strange phenomona baffled scientists, and it was only in June 2010 that a possible explanation -- a supermassive blackhole in a nearby galaxy emitting radiation and making a cloud of gas glow -- was provided. The community of amateur astronomers have cooperated to make an educational webcomic about this adventure, called "Hanny and the Mystery of the Voorwerp."

Amorin concludes: "The Galaxy Zoo volunteers have put science very close to the citizens. This is an active and powerful way to spread science."

The latest incarnation of Galaxy Zoo uses data provided by the famous Hubble Space Telescope, to peer deeper into the Universe than before. Perhaps even more citizen science discoveries are just around the corner.


Story Source:

The above story is based on materials provided by Europlanet Media Centre. Note: Materials may be edited for content and length.


Cite This Page:

Europlanet Media Centre. "Astronomer unveils the mysteries of 'Green Pea' galaxies." ScienceDaily. ScienceDaily, 12 September 2010. <www.sciencedaily.com/releases/2010/09/100910083417.htm>.
Europlanet Media Centre. (2010, September 12). Astronomer unveils the mysteries of 'Green Pea' galaxies. ScienceDaily. Retrieved March 2, 2015 from www.sciencedaily.com/releases/2010/09/100910083417.htm
Europlanet Media Centre. "Astronomer unveils the mysteries of 'Green Pea' galaxies." ScienceDaily. www.sciencedaily.com/releases/2010/09/100910083417.htm (accessed March 2, 2015).

Share This


More From ScienceDaily



More Space & Time News

Monday, March 2, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Astronauts Leave Space Station for Third Spacewalk

Astronauts Leave Space Station for Third Spacewalk

Reuters - News Video Online (Mar. 1, 2015) NASA Commander Barry Wilmore and Flight Engineer Terry Virts perform their third spacewalk in eight days outside the International Space Station. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Spacesuit Water Leaks Not An Issue On Latest ISS Walk

Spacesuit Water Leaks Not An Issue On Latest ISS Walk

Newsy (Mar. 1, 2015) Astronauts are ahead of schedule with hardware upgrades to the International Space Station, despite last week&apos;s spacesuit water leak scare. Video provided by Newsy
Powered by NewsLook.com
Black Hole 12 Billion Times the Size of Sun Discovered at Dawn of Universe

Black Hole 12 Billion Times the Size of Sun Discovered at Dawn of Universe

Buzz60 (Feb. 26, 2015) Scientists are saying they&apos;ve spotted a black hole 12 billion time bigger than the sun. Patrick Jones (@Patrick_E_Jones) has the details. Video provided by Buzz60
Powered by NewsLook.com
NASA's Dawn Spacecraft Spots Two Bright Points On Ceres

NASA's Dawn Spacecraft Spots Two Bright Points On Ceres

Newsy (Feb. 26, 2015) NASA scientists still don&apos;t have a clear picture of the bright spots showing up on the surface of Ceres, a minor planet in the asteroid belt. Video provided by Newsy
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:

Strange & Offbeat Stories


Space & Time

Matter & Energy

Computers & Math

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