Researchers Discover New Star Clusters in Milky Way

Dec 12, 2005
Researchers Discover New Star Clusters in Milky Way

Boston University researchers led a team of astronomers who recently discovered nearly 100 new star clusters in the Milky Way, each containing tens to hundreds of never before seen stars. Astronomy Professor Dan Clemens and Emily Mercer, a BU doctoral student, are members of the multi-institutional Galactic Legacy Infrared Mid-Plane Survey Extraordinaire (GLIMPSE) team.

Image: Stars Play Hide and Seek in the Milky Way

Using the dust-piercing infrared eyes of NASA’s Spitzer Space Telescope, Mercer, the discovery’s lead investigator, developed a computer method which used an algorithm to automatically sift through GLIMPSE data and identify high star density areas to look for clusters. She believes the new clusters will tell astronomers a great deal about the structure of the Milky Way and star formation within the galaxy.

“These little guys were quite hard to find,” said Mercer. “The discovery required sophisticated computer sifting of GLIMPSE data and careful inspection of the Spitzer images.”

Because the Sun and its solar system sit inside the Milky Way’s flat disk, from Earth, most of the galaxy is seen to be concentrated in a blurry band of light that stretches across the sky, known to astronomers as the galactic plane. Many of the stars in the plane cannot be seen with visible-light or ultraviolet telescopes because the clouds of dust and gas that fill the galactic spiral arms block their starlight from view.

“Emily has done a great job,” said Clemens, her BU advisor. “Her computer method for finding clusters has proved to be the most successful automated effort to date. The infrared light we’ve used is able to see through the dust better than optical light. It’s the difference between trying to see through fog and looking out on a clear day. But Emily’s computer program improved on that by telling us where in this huge data base to look for new clusters.”

By turning Spitzer’s heat-seeking infrared eyes on the Milky Way’s plane, the cold clouds of galactic gas and dust became transparent, revealing almost 100 new star clusters. Two-thirds of the new clusters were discovered through the computer method Mercer developed and the rest were found using the traditional method of visually scrutinizing GLIMPSE images for star clusters.

In addition to uncovering hundreds of hidden stars, Mercer also found that there are nearly twice as many star clusters in the portion of the galactic plane only visible from Earth's southern hemisphere, than in the northern galactic plane. She suspects that this observation may reveal to astronomers the location and nature of the Milky Way's spiral arms, the long, bright lanes of hot, massive stars seen in other galaxies, but hidden by the dust in our own.

The multi-institutional GLIMPSE team is led by Professor Edward Churchwell of the University of Wisconsin-Madison, and includes Clemens, Mercer, and other researchers in the Boston University Institute for Astrophysical Research as well as researchers at other institutions. The group was approved to survey the galactic plane with Spitzer’s Infrared Array Camera (IRAC) in November 2000, as part of Spitzer’s Legacy program. Thus far, more than 30 million stars in the inner Milky Way have been catalogued by GLIMPSE, and the team expects to identify more than 50 million stars by the end of the project.

“By making the galactic plane transparent, Spitzer opens a new door for astronomers to study the Milky Way,” said Churchwell. “Some of the most interesting science likely to come out of this project will be serendipitous discoveries, which opens up entirely new avenues of inquiry.”

Mercer’s findings are published in the December 10 issue of The Astrophysical Journal.

The Jet Propulsion Laboratory (JPL) manages the Spitzer Space Telescope mission for NASA’s Science Mission Directorate, Washington. Science operations are conducted at the Spitzer Science Center at the California Institute of Technology in Pasadena, California. JPL is a division of Caltech.

Boston University, with nearly 30,000 students enrolled in its 17 schools and colleges, is the fourth-largest independent university in the United States.

Source: Boston Univetsity

Explore further: Student science projects explode with rocket

add to favorites email to friend print save as pdf

Related Stories

Astronomy & Astrophysics: Planck 2013 results

19 hours ago

Astronomy & Astrophysics is publishing a special feature of 31 articles describing the data gathered by Planck over 15 months of observations and released by ESA and the Planck Collaboration in March 2013. ...

This star cluster is not what it seems

Sep 10, 2014

This new image from the VLT Survey Telescope in northern Chile shows a vast collection of stars, the globular cluster Messier 54. This cluster looks similar to many others but it has a secret. Messier 54 ...

Best view yet of merging galaxies in distant universe

Aug 26, 2014

Using the Atacama Large Millimeter/submillimeter Array, and other telescopes, an international team of astronomers has obtained the best view yet of a collision that took place between two galaxies when the ...

A possible signal from dark matter?

Aug 12, 2014

(Phys.org) —Galaxies are often found in groups or clusters, the largest known aggregations of matter and dark matter. The Milky Way, for example, is a member of the "Local Group" of about three dozen galaxies, ...

Recommended for you

Hubble sees 'ghost light' from dead galaxies

9 hours ago

(Phys.org) —NASA's Hubble Space Telescope has picked up the faint, ghostly glow of stars ejected from ancient galaxies that were gravitationally ripped apart several billion years ago. The mayhem happened ...

Cassini sees sunny seas on Titan

10 hours ago

(Phys.org) —As it soared past Saturn's large moon Titan recently, NASA's Cassini spacecraft caught a glimpse of bright sunlight reflecting off hydrocarbon seas.

Is space tourism safe or do civilians risk health effects?

13 hours ago

Several companies are developing spacecraft designed to take ordinary citizens, not astronauts, on short trips into space. "Space tourism" and short periods of weightlessness appear to be safe for most individuals ...

An unmanned rocket exploded. So what?

16 hours ago

Sputnik was launched more than 50 years ago. Since then we have seen missions launched to Mercury, Mars and to all the planets within the solar system. We have sent a dozen men to the moon and many more to ...

When did galaxies settle down?

16 hours ago

Astronomers have long sought to understand exactly how the universe evolved from its earliest history to the cosmos we see around us in the present day. In particular, the way that galaxies form and develop ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.