07-23-2017, 09:58 PM
It's lightning.
http://cfht.hawaii.edu/en/gallery/timelapse.php?file=20170723-c4&cam=c4
http://cfht.hawaii.edu/en/gallery/timelapse.php?file=20170723-cfhtdome&cam=cfhtdome
http://cfht.hawaii.edu/en/gallery/timelapse.php?file=20170723-c4&cam=c4
http://cfht.hawaii.edu/en/gallery/timelapse.php?file=20170723-cfhtdome&cam=cfhtdome