SH2-313

Sh2-313 (Abell 35) has long been considered a large planetary nebula located in the constellation Hydra. Jacoby, (Astrophys. J., v 244, 902-911, March 15, 1981), studied the nebula and the bright central star (HIP 62905) and estimated the distance to be approximately 1200 light years from the Earth, however, recent research indicates the distance to the central binary star system is approximately 160 parsecs (520 light years). Jacoby also deduced the central star is a binary system with a very hot white dwarf (BD 22-3467) in a close orbit. This has been subsequently verified with the temperature of the companion white dwarf in excess of 150,000 K.