Researchers publish enormous catalog of more than 300,000 nearby galaxies

More than 83,000 volunteer citizen scientists participated in the crowdsourcing project

This galaxy, NGC 4565

This galaxy, NGC 4565, is a disk galaxy viewed at nearly an edge-on angle. Galaxies like these are of particular interest for their links to star formation and the speeds at which galaxies rotate.


MINNEAPOLIS / ST. PAUL (09/23/2013) — More than 83,000 volunteer  citizen scientists. Over 16 million galaxy classifications. Information  on more than 300,000 galaxies. This is what you get when you ask the  public for help in learning more about our universe.

The project, named Galaxy Zoo 2, is the second phase of a  crowdsourcing effort to categorize galaxies in our universe. Researchers say computers are good at automatically measuring properties such as  size and color of galaxies, but more challenging characteristics, such  as shape and structure, can currently only be determined by the human  eye.

An international group of researchers, led by the  University of Minnesota, has just produced a catalog of this new galaxy  data. This catalog is 10 times larger than any previous catalog of its  kind. It is available online at data.galaxyzoo.org, and a paper describing the project and data was published today in the Monthly Notices of the Royal Astronomical Society.

View examples of images categorized by citizen scientists at http://media.cse.umn.edu/index.php/player/view/oRpOBZuwfK.

"This catalog is the first time we’ve been able to gather  this much information about a population of galaxies," said Kyle  Willett, a physics and astronomy postdoctoral researcher in the  University of Minnesota’s College of Science and Engineering and the  paper’s lead author. "People all over the world are beginning to examine the data to gain a more detailed understanding of galaxy types."

Between Feb. 2009 and April 2010, more than 83,000 Galaxy  Zoo 2 volunteers from around the world looked at images online gathered  from the Sloan Digital Sky Survey. They answered questions about the  galaxy, including whether it had spirals, the number of spiral arms  present, or if it had galactic bars, which are long extended features  that represent a concentration of stars. Each image was classified an  average of 40-45 times to ensure accuracy.  More than 16 million  classifications of more than 300,000 galaxies were gathered representing about 57 million computer clicks.

When volunteers were asked why they got involved in the  project, the most common answer was because they enjoyed contributing to science. Researchers estimate that the effort of the volunteers on this project represents about 30 years of full-time work by one researcher.

"With today’s high-powered telescopes, we are gathering so  many new images that astronomers just can’t keep up with detailed  classifications," said Lucy Fortson, a professor of physics and  astronomy in the University of Minnesota’s College of Science and  Engineering and one of the co-authors of the research paper. "We could  never have produced a data catalog like this without crowdsourcing help  from the public."

Fortson said Galaxy Zoo 2 is similar to a census of the  galaxies. With this new catalog, researchers now have a snapshot of the  different types of galaxies as they are today. The next catalog will  tell us about galaxies in the distant past. The catalogs together will  let us understand how our universe is changing.

To help create the next catalog, volunteer citizen scientists continue to be needed for the project. To participate, visit www.galaxyzoo.org. No special skills are needed, and volunteers can start classifying  galaxies and helping the scientists within minutes of going to the  website.

In addition to Fortson and Willett, other authors of the  research paper include Chris Lintott, Oxford Astrophysics and Adler  Planetarium; Steven Bamford, University of Nottingham; Karen Masters,  Robert Nichol and Daniel Thomas, University of Portsmouth and South East Physics Network; Brooke Simmons and Robert Simpson, Oxford  Astrophysics; Kevin Casteels, University of Barcelona; Edward Edmondson  and Thomas Melvin, University of Portsmouth; Sugata Kaviraj, Oxford  Astrophysics and University of Hertfordshire; William Keel, University  of Alabama; M. Jordan Raddick, Johns Hopkins University; Kevin  Schawinski, ETH Zurich; Ramin Skibba, University of California, San  Diego; and Arfon Smith, Adler Planetarium.

The research was funded primarily by the National Science  Foundation and the Leverhulme Trust. Galaxy Zoo is one of the many  online citizen science projects made available by the Zooniverse.org  team.

To read the full research paper entitled "Galaxy Zoo 2:  detailed morphological classifications for 304,122 galaxies from the  Sloan Digital Sky Survey," visit the Monthly Notices of the Royal Astronomical Society website.

Related Links
Galaxy Zoo: http://www.galaxyzoo.org/

College of Science and Engineering: http://cse.umn.edu/index.php