A New Wolf-Rayet Star and its Ring Nebula: PCG11
  In a search for new Galactic planetary nebulae from our systematic scans of the Anglo-Australian Observatory/United Kingdom Schmidt Telescope (AAO/UKST) Halpha survey of the Southern Galactic Plane, we have identified a Pop I Wolf-Rayet star of type WN7h associated with an unusual ring nebula that has a fractured rim. We present imagery in Halpha, the 843-MHz continuum from the Molonglo Observatory Synthesis Telescope (MOST), the mid-infrared from the Midcourse Space Experiment (MSX), and confirmatory optical spectroscopy of the character of the nebula and of its central star. The inner edge of the Halpha shell shows gravitational instabilities with a well-defined wavelength around its complete circumference. 
Martin Cohen (1), Quentin A. Parker (2,3), Anne J. Green (4) ((1)   Radio Astronomy Lab., UC-Berkeley, (2) Department of Phy...