Featured Research

from universities, journals, and other organizations

Even In Heaven, Stars Can Only Get So Big

Date:
February 10, 2005
Source:
University Of Michigan
Summary:
New research from the University of Michigan shows that there may be an upper limit to the mass of a star, somewhere around 120 to 200 times bigger than our sun. The sun is the closest star to Earth and therefore looks very big to us, but compared to other stars in the Milky Way, it’s considered a low-mass star.

N81 in the Small Magellanic Cloud A NASA Hubble Space Telescope "family portrait" of young, ultra-bright stars nested in their embryonic cloud of glowing gases. (NASA)

ANN ARBOR, Mich. -- New research from the University of Michigan shows that there may be an upper limit to the mass of a star, somewhere around 120 to 200 times bigger than our sun.

The sun is the closest star to Earth and therefore looks very big to us, but compared to other stars in the Milky Way, it’s considered a low-mass star. Knowing that there may be a limit to a star’s mass answers a fundamental question, but raises a raft of other issues about what limits their mass, said Sally Oey, assistant professor of astronomy.

The study is the first to determine the stellar upper mass limit by examining a wide range of star clusters, said Oey (rhymes with chewy). In the paper, “Statistical Confirmation of a Stellar Upper Mass Limit,” Oey and colleague C.J. Clarke, from the Institute of Astronomy at Cambridge, England, compared historical data on 12 OB associations, large aggregates of hundreds to several thousands of young stars.

The paper will appear in the Feb. 10 edition of the Astrophysical Journal Letters.

Other studies have suggested an upper mass limit of about the same size, but had looked at only one cluster. “Ours has more statistical significance because we were able to use many clusters,” Oey said.

Oey and Clarke looked at star clusters in the Milky Way, our galaxy, and in the Magellanic Clouds, the brightest satellite galaxies, because they are close enough to enable seeing individual stars and making measurements, Oey said.

“If you looked at any of the clusters, you’ll see roughly the same ratio of big to little stars,” Oey said. Based on the size and number of stars, the probability of finding stars above a certain mass dropped significantly at 120-200 solar masses, Oey said.

The question of mass is an important one because it relates to basic star formation, Oey said. “My African violets won’t grow any bigger now because their roots are totally taking up the maximum room in the pot,” she said. “If I repotted them they would grow larger. Are the stars maxed out because the parent clouds are limiting them, or because, like a whale in the sea, there’s something else physical about stars themselves that limits the size?

“The question about why stars have the masses that they do is fundamental, and our lack of understanding shows that we really don’t know some basics of how stars form.”

The biggest stars put out huge amounts of energy by exploding when they die or by releasing ultraviolet radiation during the star’s normal life. That puts tremendous energy into the interstellar medium, which in turn leads to evolutionary activity like renewed star formation and the conversion of gas into stars.

“If you have more stars and energy in the interstellar medium it means more evolutionary activity,” Oey said. “It stirs things up.”

Links

For information on Oey: http://www.astro.lsa.umich.edu/~msoey/publications/

View the paper on-line:

http://www.journals.uchicago.edu/ApJ/journal/issues/ApJL/v620n1/18905/18905.html


Story Source:

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


Cite This Page:

University Of Michigan. "Even In Heaven, Stars Can Only Get So Big." ScienceDaily. ScienceDaily, 10 February 2005. <www.sciencedaily.com/releases/2005/02/050205103758.htm>.
University Of Michigan. (2005, February 10). Even In Heaven, Stars Can Only Get So Big. ScienceDaily. Retrieved September 17, 2014 from www.sciencedaily.com/releases/2005/02/050205103758.htm
University Of Michigan. "Even In Heaven, Stars Can Only Get So Big." ScienceDaily. www.sciencedaily.com/releases/2005/02/050205103758.htm (accessed September 17, 2014).

Share This



More Space & Time News

Wednesday, September 17, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

East Coast Treated To Rare Meteor Sighting

East Coast Treated To Rare Meteor Sighting

Newsy (Sep. 16, 2014) Numerous residents along the East Coast reported seeing a bright meteor flash through the sky Sunday night. Video provided by Newsy
Powered by NewsLook.com
Space Race Pits Bezos Vs Musk

Space Race Pits Bezos Vs Musk

Reuters - Business Video Online (Sep. 16, 2014) Amazon CEO Jeff Bezos' startup will team up with Boeing and Lockheed to develop rocket engines as Elon Musk races to have his rockets certified. Fred Katayama reports. Video provided by Reuters
Powered by NewsLook.com
NASA’s Curiosity Rover Finally Reaches Long-Term Goal

NASA’s Curiosity Rover Finally Reaches Long-Term Goal

Newsy (Sep. 15, 2014) After more than two years, NASA’s Mars Curiosity Rover reached Mount Sharp, its long-term destination. Video provided by Newsy
Powered by NewsLook.com
SpaceX's Elon Musk Really Wants To Colonize Mars

SpaceX's Elon Musk Really Wants To Colonize Mars

Newsy (Sep. 14, 2014) Elon Musk has been talking about his goal of colonizing Mars for years now, but how much of it does he actually have figured out, and is it possible? 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:
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