Remnant of the ancients


A wide, tangled ring of thin, reddish filaments wraps around a darker central region, forming an uneven circle against a black sky. The ring is mottled and wispy, with brighter knots and fainter strands that fade into the background. Myriad small stars of varying brightness are scattered across the frame and in front of the ring.

David Cowland from Hamilton, Victoria, Australia

RCW 86 lies about 8,000 light-years away in the southern constellation Circinus. Catalogued as an emission nebula, it is the result of an expanding shell of gas and dust expelled by the explosion of a massive star 185 C.E. This event was recorded by ancient Chinese astronomers as a “guest star” — possibly the oldest identifed supernova for which surviving records exist. The imager collected 27.5 hours of data through Ha/OIII/RGB filters with an 8-inch f/4 reflector.