2025年9月16日
New Comet SWAN25B over Mexico
Image Credit & Copyright: Daniel Korona
Explanation: A newly discovered comet is already visible with binoculars. The comet, C/2025 R2 (SWAN) and nicknamed SWAN25B, is brightening significantly as it emerges from the Sun’s direction and might soon become visible on your smartphone — if not your eyes. Although the brightnesses of comets are notoriously hard to predict, many comets appear brighter as they approach the Earth, with SWAN25B reaching only a quarter of the Earth-Sun distance near October 19. Nighttime skygazers will also be watching for a SWAN25B-spawned meteor shower around October 5 when our Earth passes through the plane of the comet’s orbit. The unexpectedly bright comet was discovered by an amateur astronomer in images of the SWAN instrument on NASA‘s SOHO satellite. The comet is currently best observed in southern skies but is slowly moving north. The featured image was captured at sunset three days ago just above the western horizon in Zacatecas, Mexico.
Tomorrow’s picture: sagittarius triplet
新彗星SWAN25B现身墨西哥上空
影像提供与版权: Daniel Korona
说明: 用双筒望远镜已经可以看到一颗新发现的彗星。这颗彗星，C/2025 R2 (SWAN)，昵称为SWAN25B，随着它从太阳方向出现，亮度显著增加，很快就会在你的智慧型手机手机上可见-如果你的眼睛裸视看不到。虽然彗星的亮度难以预测，但许多彗星在接近地球时会变得更亮，SWAN25B将在10月19日左右接近地日距离的四分之一。夜间天文观测者也会观测10月5日左右当地球穿过彗星轨道平面时，SWAN25B引发的流星雨。这颗意外明亮的彗星是由业余天文学家在NASA的SOHO卫星之SWAN仪器影像中发现的。这颗彗星目前在南方天空中观测最佳，但它正在缓慢地向北移动。这张主题影像是在三天前日落时分拍摄的，位于萨卡特卡斯，墨西哥的西方地平线上方。
明日的图片: sagittarius triplet
