Milkyway:
Chi & H Persei 11-March-1988
C8 working at f10, Hypered TP2415, 15 minutes, 7 min D19 dev.
Light travel time: about 7400 years
The clusters contain a number of very bright supergiants with the brigthtest of them
nearly 60000 times more luminous than the sun. Also a number of red supergiants appear in the region of the clusters.
