2025年6月5日
Savudrija Star Trails
Image Credit & Copyright: Branko Nadj
Explanation: Savudrija lighthouse shines along the coast near the northern end of the Istrian peninsula in this well-composed night skyscape. A navigational aid for sailors on the Adriatic Sea, the historic lighthouse was constructed in the early 19th century. But an even older aid to navigation shines in the sky above, Polaris, alpha star of the constellation Ursa Minor and also known as the North Star. In this scene Polaris forms the shortest bright arc near the North Celestial Pole, the extension of Earth’s axis of rotation into space. Of course, the North Celestial Pole lies exactly at the center of all the concentric startrails. The composite image is a digital stack of 400 exposures, each 30 seconds long, taken with camera and tripod fixed to a rotating planet.
Tomorrow’s picture: pixels in space
萨乌德利加灯塔与星轨
影像提供版权: Branko Nadj
说明: 在这幅构图佳妙的夜空影像里，萨乌德利加灯塔（Savudrija lighthouse）于伊斯特拉半岛北端的海岸附近绽放光芒。这座历史悠久建于19世纪初的灯塔，是亚得里亚海水手的导航明灯。而在上方的天空中，可见到另一个更古老的航行指标─北极星，这颗有指北星之称的恒星，则是小熊座最明亮的α星。在这幅影像里，北极星在地球自转轴投射于天空的北天极附近，曳出了最短的明亮星轨。想当然耳，北天极正好位于图中所有同心星轨的中心。这幅主题影像，是由固定于旋转地球上、用三脚架支撑的相机所拍摄的400张照片组合而成，每张照片的曝光长度为30 秒。
明日的图片: pixels in space
