Mystery Alignment of Planetary Nebulae Discovered

astroengine writes "Astronomers have discovered something weird in the Milky Way's galactic bulge — a population of planetary nebula are all mysteriously pointing in the same direction. They noticed the mysterious alignment in the long axes of bipolar planetary nebulae. 'This really is a surprising find and, if it holds true, a very important one,' said Bryan Rees of the University of Manchester, co-author of the paper (PDF) to appear in the journal Monthly Notices of the Royal Astronomical Society. 'Many of these ghostly butterflies appear to have their long axes aligned along the plane of our galaxy.' The team of astronomers, who used data from Hubble and the European Southern Observatory's New Technology Telescope (NTT) to survey 130 nebulae, posit that powerful magnetic fields may be behind the phenomenon."

Comments

Re:Why is that surprising?

[amicusNYCL]

It makes sense that if all of the stars that formed the nebulae came from the same giant swirling cloud of gas, then the stars formed would tend to have angular momenta mostly aligned upon that same axis. When those stars explode later, the axis of the planetary nebula will be along this same axis.

I was thinking the same thing, but now I'm not so sure. We have at least 8 decent points of data in our solar system for orbital bodies like stars orbiting the center of gravity. Among the 8 planets, 3 of them (Me, V, J) have an axial tilt of less than 4 degrees, 4 of them (E, Ma, S, N) have an axial tilt between 23 and 29 degrees, and one of them (U) is damn near sideways. In other words, our planets are all over the place. So it would seem to make some sense if the stars orbiting the galactic center were also all over the place on their axial tilt, so it wouldn't make sense that the bipolar nebulae are all oriented in the same direction. I wonder how many nebulae this includes though. If it is roughly half of them then that would seem to be in line with our solar system.

Re:Why is that surprising?

[icebike]

Well, actually we don't know a whole hell of a lot about the revolution of stars that far away, but it sound to me like said dual-orifice ejections tend to protrude out of the poles of the stars.

That many of the poles of these stars tend to be aligned is not all that unexpected when the Galaxy itself is one huge gravitational system.