In a discovery announced on Sept. 4, 2013, a population of planetary nebulae near the galactic core appear to be, weirdly, preferentially aligned to the Milky Way's galactic plain. The nebulae, known as "bipolar" (or "butterfly") planetary nebulae are completely non-interacting and of various ages, suggesting some external force is shaping their orientation. It's thought that a powerful magnetic field may be the culprit.
The researchers used observations from the Hubble Space Telescope and ESO's New Technology Telescope, so here are a small selection of some stunning examples of bipolar planetary nebulae as seen through the eye of Hubble. Shown here is the stunning NGC 6302 -- an intricate example of a bipolar planetary nebula's butterfly wings.
Hubble 5: A classically-shaped bipolar (or 'butterfly') planetary nebula.
NGC 6881: A binary star possibly shapes this wonderfully symmetrical nebula.
NGC 5189: A dramatic view of the ribbons of bright material being ejected from a planetary nebula.
PN Hb 12: An 'hourglass'-shaped bipolar planetary nebula.
Hen 3-1475: A planetary nebula in the making.
M2-9: What appears to be twin jet engines is in fact a stunning example of a bipolar planetary nebula.