Runaway Star Is Smashing Through The Cosmos!

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Behold Zeta Ophiuchi, a runaway star. Zeta is currently booking it through the cosmos, blasting through cosmic dust. What exactly is Zeta’s deal?

Bad Astronomy:

it’s a runaway star.  It has a rather high speed compared to other stars, and we think we know why: it was once part of a binary system. It probably started off life with less mass, and it was orbiting a high mass star. The other star swelled up into a red supergiant, dumping vast amounts of material onto Zeta Oph. Then the star exploded as a supernova! When it did, it flung off Zeta Oph like a water droplet off a shaking dog. It wasn’t the explosion itself that pushed on the star; it was centripetal acceleration. The two stars were probably orbiting each other at high speed, and when the second star blew up, Zeta Oph kept that speed and flew off into space!

We see several such high-mass runaway stars, and we think that’s where they come from: they survived their partners going supernova.

But what the heck is all that stuff around it in the picture? WISE “sees” in infrared light, which is emitted by warm material like all that interstellar dust around Zeta Oph (which itself looks blue in this picture, but remember, it’s false color, even if Zeta Oph coincidentally really  is blue). Most of that dust appears green in the image. But nearer the star that dust is considerably brighter for two reasons. One is that the material is being heated by the star itself as it passes through. But also there’s a fierce wind of material streaming off of Zeta Oph’s surface, and that’s ramming the dust, compressing it. Denser material, in this case, can glow more brightly than the thinner material around it.

Man! When my partner goes supernova, she generally drops a couple of karate chops on me and kicks me out of her apartment for the evening. Zeta got flung out of its friggin’ place in the universe.