Astronomy Picture of the Day——珠穆朗玛峰的恒星行迹

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2019 March 4

MountEverest Star Trails

ImageCredit & Copyright: Jeff Dai (TWAN)

Explanation:The highest peak on planet Earth is framed in this mountain and night skyscape.On September 30, the digital stack of 240 sequential exposures made with acamera fixed to a tripod at an Everest Base Camp captured the sheer north faceof the Himalayan mountain and foreground illuminated by bright moonlight. Takenover 1.5 hours, the sequence also recorded colorful star trails. Reflecting theplanet's daily rotation on its axis, their motion is along gentle concentricarcs centered on the south celestial pole, a point well below the ruggedhorizon. The color of the trails actually indicates the temperatures of thestars. Blueish hues are from hotter stars, and yellow to reddish hues are from starscooler than the Sun.

珠穆朗玛峰的恒星行迹

解释：地球的最高峰出现在这幅夜空风景照之中。9月30日，在珠峰基地的营地里，固定在三脚架上的相机拍摄了240幅序列影像并进行了数字叠加，呈现了喜马拉雅山峰陡峭的北坡，以及被明亮月光照亮的前景。累计拍摄时间超过1.5个小时，记录到了多彩的恒星行迹，它们是地球周日自转运动的反映，形成了以南天极为中心的同心圆弧，南天极本身位于崎岖不平的地平线下方。恒星行迹的颜色实际上表征了恒星的温度，蓝色的光晕来自较为炽热的恒星，黄色到红色的光晕则来自比太阳更冷的恒星。