The former was ruled out by the eight-second modulation: a black hole is a featureless object, lacking the structure needed to produce regular pulses.

• 不过前者的嫌疑马上就被周期八秒的强弱变化所排除：黑洞是一种没有结构特徵的物体，它缺乏产生规律脉冲波所需的构造。