“There are something like a trillion galaxies in the observable universe, of a range of sizes. And galaxy collisions happen a lot. In fact, galaxies primarily grow by cannibalizing other (smaller) galaxies. Our own has eaten several—we can see streams of stars as debris. In fact, galaxies primarily…”Tagged: Space, Astronomy, Universe, Solar System, Stars
“A 'hypernova' is a supernova (exploding star), but, like, more so. (It’s defined as being any supernova that’s at least 10 times as luminous as usual.)”Tagged: Space, Astronomy, astronomical terms, Stars, Star
“A 'cataclysmic variable' is where a compact dense white dwarf star is in a binary orbit with a bigger puffier star & the WD (white dwarf) rips material off its companion & that material detonates on the WD’s surface.”Tagged: Space, Astronomy, astronomical terms, Stars
“'Violent relaxation' comes from highly technical uses of both those terms. “Relaxation” referring to a system (eg, stars in a cluster) achieving some equilibrium (steady) state, and “violent” meaning rapid. It can happen when mass comes together quickly gravitationally.”Tagged: Space, Astronomy, astronomical terms, Stars