Cygnus Loop

Cygnus Loop is a supernova remnant in the constellation Cygnus.

Large old supernova remnant

Open it on the live sky map Plan Night Exploration

Cygnus Loop: a sky-survey photograph of its field — Sky survey view (DSS2 colour, or a backup survey)

Facts

Type	Supernova remnant
Constellation	Cygnus
Position (J2000)	20h 51m 00s, +30° 40′
Size on the sky	230′ × 160′ (the full Moon is about 31′)
Filter	OIII filter (Planetary nebulae and supernova remnants shine mostly in the green light of doubly ionised oxygen: an OIII filter passes it and darkens the sky around it.)
Studied in	976 scientific papers (SIMBAD)

When and how to see it

Cygnus Loop is highest in the sky at midnight in August. From India (about 20° N) it climbs to about 79° above the horizon; from 50° N, to about 71°.

Heights are worked out for India and for 50° N. Set your location in Settings to see them for where you are.

For tonight's best time from your own town, the darkness and the Moon, open it on the map and see its "Tonight from your location" card.

More in Cygnus

Everything in Cygnus · All 88 constellations · All sky objects

Data: SIMBAD (CDS, Strasbourg; the site's weekly copy) · Data sources & credits