2025年4月18日
Comet C/2025 F2 SWAN
Image Credit & Copyright: Dan Bartlett
Explanation: In late March, the comet now designated C/2025 F2 SWAN was found independently by citizen scientists Vladimir Bezugly, Michael Mattiazzo, and Rob Matson while examining publicly available image data from the Solar Wind ANisotropies (SWAN) camera on the sun-staring SOHO spacecraft. Comet SWAN’s coma, its greenish color a signature of diatomic carbon molecules fluorescing in sunlight, is at lower left in this telescopic image. SWAN’s faint ion tail extends nearly two degrees toward the upper right across the field of view. The interplanetary scene was captured in clear but moonlit skies from June Lake, California on April 14. Seen against background of stars toward the constellation Andromeda, the comet was then some 10 light-minutes from our fair planet. Now a target for binoculars and small telescopes in northern hemisphere morning skies this comet SWAN is headed for a perihelion, its closest approach to the Sun, on May 1. That will bring this visitor from the distant Oort cloud almost as close to the Sun as the orbit of inner planet Mercury.
Tomorrow’s picture: interplanetary post-modernism
2025史旺彗星
影像提供及版权: Dan Bartlett
说明: 由3位公民科学家Vladimir Bezugly、Michael Mattiazzo和Rob Matson，分别于2025年3月下旬独立发现的彗星，目前正式命名为2025史旺彗星（C/2025 F2 SWAN）。他们是在分析观日SOHO卫星的史旺相机（太阳风异向性相机）公开影像资料时，发现了这颗彗星。于这幅望远镜影像的左下角，史旺彗星彗发里的双碳分子，在阳光中散发泛绿的萤光，而它暗淡的离子尾，则向右上方伸展绵延了将近2度的视野。4月14日在美国加州的六月湖拍摄这幅影像时，虽然月光明亮，但夜空很澄澈。史旺彗星当时位于仙女座繁星的前方，与地球的距离约为10光分。在北半球清晨天空中，目前是双筒望远镜和小望远镜观测热点的2025史旺彗星，正往太阳靠近，预计在5月1日行进到最近太阳的近日点。这颗来自遥远奥尔特云的访客，届时与太阳的间距和水星的轨道相当。
