September 13, 2013
The Tilt Of Space Butterflies
Our galaxy is vast. We here on Earth are only able to see a small portion of it when we gaze up at the night sky. It is only through the wonders of science that we able are to get a better look at what exists beyond our atmosphere. So, when we look, what are some of the things we see? Would you believe me if I told you butterflies?
To be truthful, these are not butterflies, but bipolar planetary nebulae. When a giant red star reaches the end of its days, after all of their hydrogen fuel has been exhausted, they shed much of their external layers and expel a great deal of their mass into space. At the end of its life, it becomes a red giant and absorbs much of its inner solar system into itself and becomes a planetary nebula. There are three general classifications of nebulae, which depend on the shape of them, which is determined in part by the orientation of the solar system before the star became a red giant. These classifications are “elliptical,” “either with or without an aligned internal structure,” and “bipolar.” Bipolar nebulae have expelled mass in two opposite directions, which has then collided with space dust and other particles left over from previous supernovas or other events, the result of which looks like a pair of radiant butterfly wings. `
Recently, a discovery was made regarding a number of bipolar planetary nebulae located near the center of the Milky Way; a great number of them were all tilting in the same direction. Despite these nebulae not interacting with each other, being of varying ages, and even being viewed on separate occasions, our modern day stargazers noticed that a number of them were aligned via their long axes. This phenomenon is not shared among every bipolar planetary nebula, only those that are closest to the galactic center of the Milky Way. Those that exist further out do not follow this trend. What could be causing this? Researchers believe that it is likely due to powerful magnetic fields being generated by the galactic core, much in the same way the Earth’s magnetic field influences the needle of a compass. Just as the needles point toward magnetic north (not true north, as many believe), these nebulae are pointing towards the galactic core.
So much about our galaxy is unknown to us. This one relatively small phenomena is just one of the many marvels we, humanity, are discovering every day. With each new phenomena discovered, a multitude of new questions emerge. What could this teach us? How powerful are the forces that can alter the orientation of entire nebulae? What effects does this have on our own small portion of the galaxy? The mystery of the unknown is what drives us to seek these answers.
So, the next time you gaze up at the starts, remember to think of these beautiful space butterflies.
Image Credit: ESA / NASA / Hubble