Gary Imm

GaryI

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A backyard amateur astrophotographer enjoying retirement with my wife on beautiful Lake Livingston in Onalaska, Texas, about 90 minutes north of Houston.

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About 20% of PNe are believed to be bipolar. These PNe have the most interesting shapes. To create such an axisymmetric and complex system, it is believed that the progenitor is likely a binary star system. One of the stars, late in its life during its AGB phase, grows so large that its outer envelope forms a swirling equatorial disk (torus) around the companion. The disk constrains the companion’s bi-polar flow, forming two polar lobes which expand (and sometimes break through) over time. It is important to note here that while the 2 companions are interacting, they avoid the common envelope phase for most of the interaction time (which would form a simpler elliptical PN). The "common envelope phase" is when both companion stars of the binary system share the same ejected gas envelope of the late life AGB star. This collection shows bipolar PN that we see from a side-on view, where the torus appears as a rectangle. In this view, it is easy to see the hourglass shape of the lobes. Some of the PN are experiencing lobe breakout at their ends. Multipolar PN are shown separately in a different collection.