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Cave Nebula

C9, Sh2-155

Proper NameCave Nebula
Caldwell NumberC9
NGC/IC NumberNone
Other designationsSh2-155
Right Ascension22h 57m 6s
Declination+62° 38' 9"
Distancec.2,400 light years
c.700 parsecs
MagnitudeApparent: +7.7
Absolute: -1.9
Mean DiameterApparent: 50°x30°
Actual: 39 light years
Optimum VisibilitySeptember (Usually visible from northern latitudes)
NotesAn area of nebulosity some seventy light years from side to side, much of this bright emission nebula is obscured by a broad dark cloud so that, as seen from Earth, it appears as a ragged arc of light reminiscent of a cave's mouth.