Featured Research

from universities, journals, and other organizations

Universe's most massive stars can form in near isolation, new study finds

Date:
December 22, 2010
Source:
University of Michigan
Summary:
New observations by astronomers add weight to the theory that the most massive stars in the universe could form essentially anywhere, including in near isolation; they don't need a large stellar cluster nursery.

Left: Star 302, as viewed from the ground. Right: Star 302 as viewed through the Hubble Space Telescope, which can zoom in roughly 40 times closer. From the ground, everything within the circle appears to be one star.
Credit: Courtesy of Joel Lamb

New observations by University of Michigan astronomers add weight to the theory that the most massive stars in the universe could form essentially anywhere, including in near isolation; they don't need a large stellar cluster nursery.

This is the most detailed observational study to date of massive stars that appear (from the ground) to be alone. The scientists used the Hubble Space Telescope to zoom in on eight of these giants, which range from 20 to 150 times as massive as the Sun. The stars they looked at are in the Small Magellanic Cloud, a dwarf galaxy that's one of the Milky Way's nearest neighbors.

Their results, published in the Dec. 20 edition of The Astrophysical Journal, show that five of the stars had no neighbors large enough for Hubble to discern. The remaining three appeared to be in tiny clusters of ten or fewer stars.

Doctoral student Joel Lamb and associate professor Sally Oey, both in the Department of Astronomy, explained the significance of their findings.

"My dad used to fish in a tiny pond on his grandma's farm," Lamb said. "One day he pulled out a giant largemouth bass. This was the biggest fish he's caught, and he's fished in a lot of big lakes. What we're looking at is analogous to this. We're asking: 'Can a small pond produce a giant fish? Does the size of the lake determine how big the fish is?' The lake in this case would be the cluster of stars.

"Our results show that you can, in fact, form big stars in small ponds."

The most massive stars direct the evolution of their galaxies. Their winds and radiation shape interstellar gas and promote the birth of new stars. Their violent supernovae explosions create all the heavy elements that are essential for life and the Earth. That's why astronomers want to understand how and where these giant stars form. There is currently a big debate about their origins, Oey said.

One theory is that the mass of a star depends on the size of the cluster in which it is born, and only a large star cluster could provide a dense enough source of gas and dust to bring about one of these massive stars. The opposing theory, and the one that this research supports, is that these monstrous stars can and do form more randomly across the universe -- including in isolation and in very small clusters.

"Our findings don't support the scenario that the maximum mass of a star in a cluster has to correlate with the size of the cluster," Oey said.

The researchers acknowledge the possibility that all of the stars they studied might not still be located in the neighborhood they were born in. Two of the stars they examined are known to be runaways that have been kicked out of their birth clusters. But in several cases, the astronomers found wisps of leftover gas nearby, strengthening the possibility that the stars are still in the isolated places where they formed.

The research is funded by NASA and the National Science Foundation.


Story Source:

The above story is based on materials provided by University of Michigan. Note: Materials may be edited for content and length.


Journal Reference:

  1. J. B. Lamb, M. S. Oey, J. K. Werk, L. D. Ingleby. The Sparsest Clusters With O Stars. The Astrophysical Journal, 2010; 725 (2): 1886 DOI: 10.1088/0004-637X/725/2/1886

Cite This Page:

University of Michigan. "Universe's most massive stars can form in near isolation, new study finds." ScienceDaily. ScienceDaily, 22 December 2010. <www.sciencedaily.com/releases/2010/12/101221131550.htm>.
University of Michigan. (2010, December 22). Universe's most massive stars can form in near isolation, new study finds. ScienceDaily. Retrieved September 30, 2014 from www.sciencedaily.com/releases/2010/12/101221131550.htm
University of Michigan. "Universe's most massive stars can form in near isolation, new study finds." ScienceDaily. www.sciencedaily.com/releases/2010/12/101221131550.htm (accessed September 30, 2014).

Share This



More Space & Time News

Tuesday, September 30, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

The Water You Drink Might Be Older Than The Sun

The Water You Drink Might Be Older Than The Sun

Newsy (Sep. 27, 2014) Researchers at the University of Michigan simulated the birth of planets and our sun to determine whether water in the solar system predates the sun. Video provided by Newsy
Powered by NewsLook.com
First Woman Cosmonaut in 17 Years Blasts Off for ISS

First Woman Cosmonaut in 17 Years Blasts Off for ISS

AFP (Sep. 26, 2014) A Russian Soyuz spacecraft carrying an American astronaut and two Russian cosmonauts, including the first woman cosmonaut in 17 years, blasted off on schedule Friday. Duration: 00:35 Video provided by AFP
Powered by NewsLook.com
Water Discovery On Small Planet Could Be Key To Earth 2.0

Water Discovery On Small Planet Could Be Key To Earth 2.0

Newsy (Sep. 25, 2014) Scientists have discovered traces of water in the atmosphere of a distant, Neptune-sized planet. Video provided by Newsy
Powered by NewsLook.com
Raw: US-Russian Crew Lifts Off for Space Station

Raw: US-Russian Crew Lifts Off for Space Station

AP (Sep. 25, 2014) A U.S.-Russian space crew has blasted off successfully for the International Space Station. The Russian Soyuz-TMA14M spacecraft lifted off from the Russian-leased Baikonur launch facility in Kazakhstan. (Sept. 25) Video provided by AP
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