Comet Holmes - it's quite simple

This isn't unusual.

Comet Holmes and the case of the Disappearing Tail | The Register

"Amateur astronomers the world over have been stunned and amazed by the weirdest new object to appear in the sky in memory," wrote Sky and Telescope .

"The comet shocked skywatchers as it went from a dim 17th magnitude then suddenly to 3 magnitude" wrote Theo from the Pacific Northwest.*

Zorgonian battle cruisers always do that on approach to the target system.