North Star, Polaris, Alan Penny
John Elder/Creative Commons 2.5

North Star Makes a Comeback

July 25, 2008 04:54 PM
by findingDulcinea Staff
Despite fears that the star was fading away, astronomers now say it appears to have recovered and is increasing in brightness.

30-Second Summary

The North Star's vibrations had been lessening over the past 100 years to the extent that astronomers expected them to stop altogether.

"Now they have been stunned to discover the star seems to have come back to life again," writes The Scotsman, which reports that scientists do not yet have an explanation for the sudden change.

An international team of astronomers recently found that the star's vibrations have been increasing for the past 10 years, according to Glasgow newspaper The Herald.

The results were presented by Dr. Alan Penny of the School of Physics and Astronomy to delegates at the Cool Stars 15 conference, held at the University of St. Andrews in Scotland from July 21-24.

"One hundred years ago Polaris varied by 10%, but over the last century the variations became smaller and smaller until 10 years ago it only varied by 2%. It was thought the structure of the star was changing to switch off the vibration," Dr. Penny said. "Yet the team has found that about 10 years ago the vibrations started picking up and are now back up at the 4% level."

The North Star, also called the Northern Star or Polaris, is a pole star that lies closest in the sky to the north celestial pole. It is a Cepheid variable star, meaning that it changes in brightness about every four days.

Headline Links: North Star's brightness strengthening

Key Player: Dr. Alan Penny

Related Topics: 'Super-Earths' and other recent astronomical breakthroughs


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