Speed Kills

Listen 07:49
Image: NASA, ESA, and D. Coe, J. Anderson, and R. van der Marel (STScI)

Image: NASA, ESA, and D. Coe, J. Anderson, and R. van der Marel (STScI)

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. Crystallization as a diamond comes because the core of many white dwarf stars is composed on oxygen and carbon, the essential ingredients in diamond composition. The thinking is that as the core cools below 18 million degrees, the crystallization begins converting the core into solid oxygen and carbon or diamond. Thinking about staking a claim? Good luck! These stars are very dim, not to mention their distance and the logistics involved in an attempt to mine something like this. But wait, there’s hope: Our sun is predicted to go diamond in about 10 billion years.

Clear dark sky highlights: Venus and Jupiter dominate the pre-dawn sky this coming week. Mars and the moon are next to each other tonight.

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