North Star 'Polaris' closer to Earth than thought
Washington: The famed North Star, which has been a beacon in the night sky throughout human history, is actually closer to our solar system than previously thought, a new study has claimed.
Scientists studying the North Star Polaris found that it is about 323 light-years from the sun and Earth, substantially closer than a previous estimate of 434 light-years by a European satellite in the late 1990s.
According to the researchers, the new distance measurement may help astronomers in the pursuit of several cosmic mysteries like the hunt for elusive dark energy.
Polaris is what astronomers call a Cepheid variable star, a pulsating star used by scientists to measure distances in space. Astronomers can measure the distance to a Cepheid variable by studying how it changes in brightness over time.
Since Polaris is the nearest Cepheid variable star to our solar system, an accurate distance to the star could serve as a benchmark for measurements of other Cepheids used to determine the scale of the universe.
In the 1990s, the European Space Agency’s star-mapping Hipparcos satellite determined the 434 light-year distance to Polaris, while other studies suggested the star could be closer to the sun. One light-year is the distance light travels in a single year, about 6 trillion miles.
The new study by astronomers in Canada, Ukraine and Belgium confirmed the closer distance using new high-resolution observations of the star''s light spectrum.
“Polaris presents certain anomalies that have so far defied a straightforward interpretation,” CBS News quoted study leader David Turner from Canada’s Saint Mary’s University in Halifax as saying in a statement.
“Our high-resolution spectroscopic observations of Polaris may signal the beginning of a new era in understanding the star,” he said.
The study has been published in the Astrophysical Journal Letters.