Hubble Space Telescope imaged the center of the giant elliptical galaxy M87 and revealed a small disk of gas surrounding the core. The blue the red lines show the Doppler shifts (blue shift when the source is approaching, red shift when it is receding) in the spectral lines caused by the rapid rotation of the disk.

这是哈勃太空望远镜拍摄的巨椭圆星系M87的照片,照片显示有一个气体盘围绕核心旋转。蓝色曲线和红色曲线分别代表来自气体盘的多普勒蓝移和红移的谱线，蓝移和红移分别是由于气体向观测者趋近和退离而引起的，这就是天文学家推断气体盘围绕星系中心迅速旋转的理由。天文学家认为在M87的中心也有一个超大质量黑洞。