'North Star closer to Earth than thought'

The famed North Star navigation beacon in the night sky throughout history - is actually much closer to our solar system than previously thought, scientists say.

Researchers 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.

Researchers said the new distance measurement may help astronomers in the pursuit of several cosmic mysteries, such as the hunt for elusive dark energy, 'Live Science' reported.

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.

The European Space Agency's star-mapping Hipparcos satellite determined the 434 light-year distance to Polaris in the 1990s, while other studies suggested the star could be closer to the Sun.

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," said study leader David Turner of Canada's Saint Mary's University.

"Our high-resolution spectroscopic observations of Polaris may signal the beginning of a new era in understanding the star," said Turner.

Polaris gained its reputation as the North Star due to its location in the night sky, which is aligned with the direction of Earth's axis.

Polaris remains in a fixed position in the northern sky, unlike other stars, which appear to rise and set over the course of a night as the Earth rotates, making it a valuable navigation beacon.

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