I’m thinking large numbers of synchronized reusable beacons—either recurrent novas or black holes—where a flash is produced by feeding the beacon with gas in a controlled way. For rapid reuse, you want local byproducts of the flash to get out of the way quickly, so the next batch of gas can be introduced. That could mean dwarf novas, or black hole processes in which the waste comes out in tightly focused jets.
There is a “remarkable recurrent nova” in the Andromeda Galaxy, which repeats on a timescale of months.
I’m thinking large numbers of synchronized reusable beacons—either recurrent novas or black holes—where a flash is produced by feeding the beacon with gas in a controlled way. For rapid reuse, you want local byproducts of the flash to get out of the way quickly, so the next batch of gas can be introduced. That could mean dwarf novas, or black hole processes in which the waste comes out in tightly focused jets.
There is a “remarkable recurrent nova” in the Andromeda Galaxy, which repeats on a timescale of months.