Added 1 new A* page:The BBC had a trifecta of pretty interesting space news articles a day or two ago:
- Background light suggests many stars 'outside galaxies': There is more light coming in than the galaxies we know about can account for, apparently, and a new analysis of this light, reading certain types of "ripples" in it, has inferred that "as many as half" of the stars in the universe may be floating free in the vast spaces between galaxies, rather than concentrated in galaxies themselves—but this finding is contested, as others say the light could be coming from very very distant galaxies. Anyway, you don't often hear much about the stars that certainly must be drifting freely through intergalactic space in large numbers, but this article goes on about them at some length.
- Mystery over monster cosmic cloud: Astronomers studying Sagittarius (aka "Sgr") A*, the supermassive black hole at the center of our galaxy, for a while now have been making much of a large gas cloud, dubbed G2, that seemed on a collision course with the black hole, anticipating that they'd get to see what would happen as the hole tore the cloud apart. But that...didn't happen; instead, G2 passed its closest approach (36 light hours) to A* perfectly intact, defying simulations of what should happen to a gas cloud passing that close to a black hole of 4 million solar masses. So now some astronomers are concluding that G2 must be a star, rather than a gas cloud—like maybe a binary star system that merged into one star on its way in toward A*. This, also, is contested. ; ) There's a more credulous and perhaps less balanced discussion of the star theory over here.
- Planet formation captured in photo: the Atacama Large Millimeter/submillimeter Array ("ALMA") in the high Chilean desert shows off its new radio-image resolving power in a spectacular photo of a newly forming solar system 450 light years away, in which you can actually see the tracks being carved in the system's protoplanetary disc of hot gas by baby planets! The central star, HL Tau, is just a million years old (our own Sun is 4.6 billion years old), and—well jeez, just go look at the photo, it's amazing to think about!
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