Central Stars of Planetary Nebulae

IC 4663

In addition to studies of massive stars, some low and intermediate mass stars pass through a phase at the end of their (long) life when a `Planetary Nebula' is being formed, in which late pulses remove surface hydrogen layers, revealing a spectrum reminiscent of massive stars - a subset of these Central Stars of Planetary Nebulae (CSPN) exhibit a Wolf-Rayet spectrum. I have studied a variety of these with Orsola De Marco - e.g. SwSt1.

Although many examples of carbon-sequence Wolf-Rayet CSPNe are known, we have identified the first unambiguous example of a nitrogen-sequence CSPNe, IC 4663. The image of IC4663 to the right shows a greyscale Gemini image ([OIII]) plus a colour HST composite (RGB = Halpha, [OIII], V-band).