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Polaris

Polaris, also known as the North Star, is a multiple-star system located nearly at the North Celestial Pole in the constellation Ursa Minor. Its brightest component, Polaris A, is a classical Cepheid variable supergiant approximately 430 light-years from Earth. The system appears nearly fixed in the sky, making it an important navigational reference.

Source: science.nasa.gov

APODs including "Polaris"

North Star: Polaris and Surrounding Dust

14/01/2025

North Star: Polaris and Surrounding Dust
Image Credit: Davide Coverta / NASA APOD

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 on 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 surface of Cepheid Polaris slowly pulsates, causing the famous star to change its brightness by a few percent over the course of a few days. Today: Zoom APOD Lecture hosted by the Amateur Astronomers of Association of New York