北京古观象台上空的星轨

2023年12月2日

Startrails over Beijing Ancient Observatory
Image Credit & Copyright: Jeff Dai (TWAN)

Explanation: You can take a subway ride to visit this observatory in Beijing, China but you won’t find any telescopes there. Starting in the 1400s astronomers erected devices at the Beijing Ancient Observatory site to enable them to accurately measure and track the positions of naked-eye stars and planets. Some of the large, ornate astronomical instruments are still standing. You can even see stars from the star observation platform today, but now only the very brightest celestial beacons are visible against the city lights. In this time series of exposures from a camera fixed to a tripod to record graceful arcing startrails, the brightest trail is actually the Moon. Its broad arc is seen behind the ancient observatory’s brass armillary sphere. Compare this picture from the Beijing Ancient Observatory taken in September 2023 to one taken in 1895.

Tomorrow’s picture: moonset

北京古观象台上空的星轨
影像提供与版权: Jeff Dai（戴建峰） (TWAN)

说明: 你可以坐地铁去参观这座在中国北京的天文台，但在那里却无法找到任何望远镜。从1400年代开始，天文学家就开始在北京古观象台上架设仪器，以准确测量和追踪裸视恒星和行星的位置。其中部分的大型华丽天文仪器，至今仍然屹立在那。如今，你甚至可以在观星台上观赏星星，不过在都市灯火的映衬下，只有最明亮的天体才得见。这幅使用固定在三脚架上的相机所拍摄的时序影像，记录了数道优美的弧形星轨，而最亮的那道实际上是来自月亮。它宽阔的迹线，则位在古观象台黄铜浑天仪的后方。另外，不妨把这张摄于2023年9月的北京古观象台影像与1895年的照片进行比较。

明日的图片: moonset