NEBULAE & STAR CLUSTERS A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  Q  R  S  T  U  V  W  X  Y  Z                    HOME ABOUT CATEGORIES SITE MAP COPYRIGHT ADVERTISE CONTACT entire Web this site Abell 39 Abell 39 Credit: George Jacoby (WIYN Obs.) et al., WIYN, AURA, NOAO, NSF An almost perfectly spherical planetary nebula in the constellation Hercules. Discovered in 1966 by George Abell, it is one of the largest known spheres in our Galaxy. Its shape has allowed astronomers to accurately estimate how much relative material in the nebula is absorbing and emitting light. Observations indicate that Abell 39 contains has only about half the abundance of oxygen found in the sun. The reason why the central star is slightly off center, by 0.1 light-year, is currently unknown. Visual magnitude 13.7 (integrated); 15.7 (central star) Angular diameter 3.9' Linear diameter 5 light-years Distance ~ 7,000 light-years Position R.A. 16h 27m 32.6s; Dec. +27° 54' 29" Other designations PNG 047.0+42.4, PK 047+42.1, ARO 180 Related category    • NEBULAE AND STAR CLUSTERS Also on this site: Encyclopedia of Alternative Energy & Sustainable Living Encyclopedia of History Transport Concepts & Designs (partner site) BACK TO TOP