Speed Kills

The more scientists learn about black holes, the more the findings confirm the warning: Speed kills.
The black hole ASASSN-14li lies at the heart of a galaxy 290 million light-years away from Earth and harbors between 1 million and 10 million times the mass of the sun. That makes it about as hefty as the black hole at our Milky Way galaxy’s core, known as Sagittarius A*, which contains about 4 million solar masses.
Focusing on ASASSN-14li, astronomers at MIT just announced a new way to measure the rotation of black holes: Look for the remnants of partially consumed stars as regular pulses of x-rays as the star spins around with the black hole’s spin.
In this case, the ‘pulse’ recurred every 131 seconds for 450 days; and with that, it was determined that the black hole spins at 50% of the speed of light (186,000 miles / second).
More info here.
A new study confirms an earlier claim that the cores of white dwarf stars eventually crystallize as they cool. Crystalli