2025年11月2日
哈勃望远镜拍摄的马蹄形爱因斯坦环
影像提供: ESA/Hubble & NASA
说明: 什么东西庞大且蓝，还能够包裹整个星系？那就是引力透镜海市蜃楼。如图所示，一个巨大的椭圆星系（明亮的红色星系：LRG）的引力扭曲了来自更遥远的蓝色星系之光线。通常情况下，这种光线弯曲会导致遥远星系形成两个可辨别的影像，但在这里，透镜对准非常精确，以至于背景星系被扭曲成马蹄形-一个几乎完整的环：爱因斯坦环。虽然LRG 3-757是在2007年由斯隆数位巡天（SDSS）数据中发现的，但上图是使用哈勃太空望远镜的广角相机3进行的后续观测结果。最近对中心星系的透镜分析显示它可能拥有迄今发现的最大质量黑洞：其质量是我们太阳质量的360亿倍。
明日的图片: double helix eclipse
Due to the lapse in federal government funding, NASA is not updating APOD website. We sincerely regret this inconvenience.
由于美国联邦政府资金中断，NASA目前暂停更新APOD网站。对此带来的不便，我们深感抱歉。
英文原文:
Explanation: What’s large and blue and can wrap itself around an entire galaxy? A gravitational lens mirage. Pictured here , the gravity of a massive elliptical galaxy (luminous red galaxy: LRG ) has gravitationally distorted the light from a much more distant blue galaxy. More typically, such light bending results in two discernible images of the distant galaxy, but here the lens alignment is so precise that the background galaxy is distorted into a horseshoe — a nearly complete ring: an Einstein ring . Although LRG 3-757 was discovered in 2007 in data from the Sloan Digital Sky Survey (SDSS), the image shown above is a follow-up observation taken with the Hubble Space Telescope ‘s Wide Field Camera 3 . A recent lens analysis of the central galaxy indicate that it likely hosts the single most massive black hole yet discovered: 36 billion times the mass of our Sun.
