The North Star: Polaris and Surrounding Dust
Why is Polaris called the North Star? First, Polaris is the nearest bright star toward the north spin axis of the Earth. Therefore, as the Earth turns, stars appear to revolve around Polaris, but Polaris itself always stays in the same northerly direction— making it the North Star. Since no bright star is near the south spin axis of the Earth, there is currently no bright South Star. Thousands of years ago, Earth's spin axis pointed in a slightly different direction so that Vega was the North Star.
Although Polaris is not the brightest star in the sky, it is easily located because it is nearly aligned with two stars in the cup of the Big Dipper. Polaris is near the center of the five-degree wide featured image, a digital composite of hundreds of exposures that brings out faint gas and dust of the Integrated Flux Nebula (IFN) all over the frame. The IFN is an extremely faint glow caused by the combined light of the stars of the Milky Way reflected and re-emitted by interstellar gas and dust
Meanwhile, the surface of the cepheid variable star, Polaris, slowly pulsates, causing this famous stellar object to change its brightness by a few percent over the course of only a few days.
Distance: ~323-433 light years
Release Date: Jan. 14, 2025
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