TITLE: "Planetary Nebula Formation: Old Stars Blowing Cosmic Bubbles."

SPEAKER: Professor Susan R. Trammell,

Planetary nebulae are the grand finale of stellar evolution for stars similar to the Sun. These objects appear in the night sky as bubble-like, gaseous structures that exhibit a variety of morphologies ranging from ring-like to bipolar. During a brief phase of stellar evolution, approximately 25,000 years, a red giant star sheds its outer layers, becomes a PN, and then begins to cool as a white dwarf. I have studied planetary nebuale using the Hubble Space Telescope and a variety of ground-based techniques. I will discuss the results of a program to study very young planetary nebulae and the implications of these data on our picture of the development and evolution of these objects.