OMG! I saw that this morning on Regis. Kelly Ripa said it looked like a butterfly then Gelman said it looked like a mammogram.
well it's the butterfly nebula. and picture of the day on APOD. mmm, I love that site
It's very pretty! What is that that's cinching it in the middle?
why my dear, that would be a supernova, at the center of all nebulae.
(or maybe a couple of them)
right! the reason it looks pinched is because you have essentially a war between the outward explosive forces of the supernova and the
dense dust and gas that surrounds it.
obviously the supernovae would want to explode out in all directions, but sometimes the dust is just dense enough to prevent that.
And hence the pretty Butterfly nebula!