指北星: 北极星及其周围的尘埃
A bright star is pictured in the center of field filled with glowing gas and dust and other, more faint, stars. Please see the explanation for more detailed information.
图像中央是一颗明亮的恒星，周围充满发光的气体和尘埃，以及其他较暗的恒星。有关更多详细信息，请参阅说明。
北极星及其周围的尘埃
2023年4月11日 North Star: Polaris and Surrounding Dust Image Credit & Copyright: Javier Zayaz Explanation: 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…