"But what is a black hole exactly? Has anyone ever described it to you? Most people know it as a dead star, but what does that mean?"
https://www.nature.com/scitable/blog/realscization/if_a_black_hole_is/
"While astronomers look for a ninth planet to explain orbits in the outer solar system, a duo explores the possibility that the mystery object is a primordial black hole."
https://physics.aps.org/articles/v13/s97
"Harvard University astronomers now raise the possibility that orbital evidence for Planet 9 could possibly be the result of a missing link in the decades-long puzzle of dark matter. That is, a hypothetical primordial black hole (PBH) with a horizon size no larger than a grapefruit, and with a mass 5 to 10 times that of Earth."
https://www.forbes.com/sites/brucedorminey/2020/07/11/is-planet-9-actually-a-primordial-black-hole/?sh=4cdcec654d80
"Just outside the hole, however, the material being pulled into the hole’s gravity well is accelerated to near the speed of light. The molecules of the material collide with such vigour that it is heated up to a temperature of hundreds of millions of degrees. When astronomers study black holes, this is the material that they see.
The radiation from the material masks the tiny amount of radiation escaping from the hole itself, and so what the astronomers observe is the very hot outside environment, rather than the freezing cold environment inside."
https://www.sciencefocus.com/space/are-black-holes-hot-or-cold
"The correct figure is 50 billion miles."
"the mystery body is so cold its temperature is no more than 40 degrees above "absolute" zero, which is 456 degrees Fahrenheit below zero. The telescope aboard IRAS is cooled so low and is so sensitive it can "see" objects in the heavens that are only 20 degrees above absolute zero.
When IRAS scientists first saw the mystery body and calculated that it could be as close as 50 trillion miles, there was some speculation that it might be moving toward Earth."
https://www.washingtonpost.com/archive/politics/1983/12/30/possibly-as-large-as-jupiter/1075b265-120a-4d40-9493-a8c523b76927/
Planet 9 could be a black hole | Konstantin Batygin and Lex Fridman
Scientists Found New Evidence for the Existence of Planet X!
Black Hole Sun Lyrics
https://genius.com/Soundgarden-black-hole-sun-lyrics
