It is the ability to separate two closely-spaced stars into two distinct images measured in seconds of arc.
也就是能够分开两个距离很近的两颗星的能力,单位是角秒1(seconds of arc)。
2
If the center of NGC 4258 were a star cluster, the stars would be so closelyspaced that collisions between individual stars would have long ago torn the cluster apart.
如果 NGC 4258 的中心是一个星团,恒星之间的距离会非常近,以至于在很久以前单个恒星之间的碰撞就会把星团撕裂。
3
NIST scientists start with lasers that emit a continuous train of very brief, closelyspaced pulses of light containing a million different colors.