It's a Fine Line Between a Black Hole Energy Factory and a Black Hole Bomb

By Brian Koberlein - January 29, 2024 02:12 PM UTC | Black Holes
You might be surprised to learn there's a way to extract enormous energy from a rapidly spinning black hole. Known as the "Penrose Process," an advanced civilization would feed material into a black hole and extract energy as some of it is hurled into space. A new paper suggests that the process could be even more efficient, cycling the material back into the black hole for another round. Or maybe this will turn into an extremely powerful bomb.
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New Types of Hidden Stars Seen for the First Time

By Brian Koberlein - January 28, 2024 11:47 AM UTC | Stars
Astronomers performing a vast infrared variable star survey have discovered new additions to the stellar menagerie. These new types of stars are normally hidden by gas and dust, but infrared radiation can pierce the shroud, revealing them for the first time. They watched hundreds of millions of stars, noting 222 that showed the greatest changes in brightness. Some were protostars coming to life, and others were ancient stars shedding material in their old age.
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Nancy Grace Roman Could Find the First Stars in the Universe

By Brian Koberlein - January 26, 2024 03:12 PM UTC | Cosmology
The first stars in the Universe were made out of the primordial hydrogen and helium left over from the Big Bang. They were probably monsterous, with dozens or even hundreds of times the mass of the Sun. They lived short lives and then detonated as supernovae. Current telescopes will have a tough time spotting these stars, but a new paper suggests that the upcoming Nancy Grace Roman Telescope might have a clever trick to spot them.
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