Zisnea begizta, supernoba baten eztandak sortutako nebulosa igorle konplexua da non zeruan 3 gradu zabal eta atal ezberdinez izandatutako nebulosa den, NGC 6960, NGC 6992, NGC 6995, IC1340, Pickering-en triangelua, NGC 6974 eta NGC 6979. Jatorriko supernobak 20 eguzki masa zituen eta duela 10.000 eta 20.000 urte bitarte lehertu zen. Leherketaren momentuan, supernoba Artizarra baino diztiratsuagoa zen zeruan eta egunez ikusgai.

The Cygnus Loop is a large supernova remnant (SNR) in the constellation Cygnus, an emission nebula measuring nearly 3° across with several components with separate names, NGC 6960, NGC 6992, NGC 6995, IC1340, Pickering's Triangle, NGC 6974 and NGC 6979. The source supernova was a star 20 times more massive than the Sun which exploded between 10,000 and 20,000 years ago. At the time of explosion, the supernova would have appeared brighter than Venus in the sky, and visible in daytime.