Featured Research

from universities, journals, and other organizations

Southern Star Pulsates Like The Sun, Say Astronomers; Australian Telescope Measures Beta Hydri's Solar-Like Oscillations

Date:
February 12, 2001
Source:
National Science Foundation
Summary:
An international team of astronomers has precisely measured the oscillations of a sun-like star. The measurements provide clues to the star's internal structure that will help scientists test models and theories of stellar evolution.

An international team of astronomers has precisely measured the oscillations of a sun-like star. The measurements provide clues to the star's internal structure that will help scientists test models and theories of stellar evolution.

Beta Hydri is a nearby star in the constellation Hydrus, or Southern Water Snake. It is similar to the sun in mass and temperature, but is estimated to be about seven billion years old, compared to about 4.5 billion years for the sun.

"Beta Hydri gives us a good idea of what the sun will look like in a few billion years," said researcher Tim Bedding of the University of Sydney. Bedding, Paul Butler of the Carnegie Institution of Washington and colleagues from the United States, Australia, Denmark and Switzerland studied the star with the 3.9 meter Anglo-Australian Telescope at Siding Spring, Australia. The research is supported by the National Science Foundation.

By learning about the structure of such stars, scientists can test theories about the creation, structure and eventual demise of stars like our sun. These theories are tested by comparing actual data with predictions generated by computer models. Today's computers can simulate billions of years of aging of a star in minutes.

Bedding's and Butler's team precisely measured tiny, periodic variations, or oscillations, in the velocity of material moving on or near the surface of the star. Twelve hundred measurements were taken over five nights in June 2000. The results will be published in an upcoming issue of the Astrophysical Journal Letters.

Ever since the discovery in 1979 of tiny oscillations -with periods of as little as five minutes -- on the surface of the sun, scientists have looked for the same minute motions in stars similar to the sun. Since Beta Hydri is older than the sun, the oscillation periods were expected to be longer, on the order of 15 to 20 minutes. The astronomers found, indeed, that the star's oscillation period was 17 minutes.

Just as seismologists use sound waves to probe the interior of the earth, astronomers use similar techniques to probe the interior of a star and determine details such as temperature, rotation and composition. Because oscillation periods increase as stars get older, these techniques also allow scientists to estimate the ages of stars.

"Detecting these seismic waves on Beta Hydri is like feeling the pulse of the star," said Butler. "Just as a person's pulse reveals information about the heart, these oscillations allow us to peer deep into the center of the star to tell us about conditions there."

The team used a spectroscopic technique developed by Butler and Geoff Marcy, of the University of California at Berkeley, to detect tiny velocity variations in astronomical objects. Butler, Marcy and other colleagues have used the technique to find new planets, including three recently detected with the Anglo Australian telescope.

Studies of another star, Procyon, have also revealed evidence of oscillations similar to those of the sun. However, Bedding's and Butler's team believes the measurements of Beta Hydri provide the clearest evidence to date.

For illustrations see:http://www.physics.usyd.edu.au/~bedding/mons/visual.html andhttp://www.aao.gov.au/images.html/captions/aat001.html


Story Source:

The above story is based on materials provided by National Science Foundation. Note: Materials may be edited for content and length.


Cite This Page:

National Science Foundation. "Southern Star Pulsates Like The Sun, Say Astronomers; Australian Telescope Measures Beta Hydri's Solar-Like Oscillations." ScienceDaily. ScienceDaily, 12 February 2001. <www.sciencedaily.com/releases/2001/01/010131074905.htm>.
National Science Foundation. (2001, February 12). Southern Star Pulsates Like The Sun, Say Astronomers; Australian Telescope Measures Beta Hydri's Solar-Like Oscillations. ScienceDaily. Retrieved September 3, 2014 from www.sciencedaily.com/releases/2001/01/010131074905.htm
National Science Foundation. "Southern Star Pulsates Like The Sun, Say Astronomers; Australian Telescope Measures Beta Hydri's Solar-Like Oscillations." ScienceDaily. www.sciencedaily.com/releases/2001/01/010131074905.htm (accessed September 3, 2014).

Share This



More Space & Time News

Wednesday, September 3, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: NASA Captures Solar Flare

Raw: NASA Captures Solar Flare

AP (Sep. 1, 2014) NASA reported the sun emitted a mid-level solar flare, on August 24th. NASA's Solar Dynamics Observatory captured the images of the flare, which erupted on the left side of the sun. (Sept. 1) Video provided by AP
Powered by NewsLook.com
Space Shuttle Discovery's Legacy, 30 Years Later

Space Shuttle Discovery's Legacy, 30 Years Later

Newsy (Aug. 30, 2014) The space shuttle Discovery launched for the very first time 30 years ago. Here's a look back at its legacy. Video provided by Newsy
Powered by NewsLook.com
Experiment Tests Whether Universe Is Actually A Hologram

Experiment Tests Whether Universe Is Actually A Hologram

Newsy (Aug. 27, 2014) Researchers at Fermilab are using a device called "The Holometer" to test whether our universe is actually a 2-D hologram that just seems 3-D. Video provided by Newsy
Powered by NewsLook.com
SpaceX’s Falcon 9 Rocket Explodes After Liftoff

SpaceX’s Falcon 9 Rocket Explodes After Liftoff

Newsy (Aug. 23, 2014) The private spaceflight company says it is preparing a thorough investigation into Friday's mishap. 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