What makes black hole so heavy even it's tiny in size?
Phobos said:A star like our sun will compact down to an object called a white dwarf which will be about the size of the planet Earth.
Blackholes can't be seen directly, because light cannot escape them. They are detected from the X-rays that the accretion disks they form. When material falls into a black hole from a companion star, it gets heated to millions of degrees Kelvin and accelerated. The superheated materials emit X-rays, which can be detected by X-ray telescopes such as the orbiting Chandra X-ray Observatory. The star Cygnus X-1 is a strong X-ray source and is considered to be a good candidate for a black hole. Stellar winds from the companion star, blow material onto the accretion disk surrounding the black hole. As this material falls into the black hole, it emits X-rays.kiru said:Do you mean that the black hole is perfectly black?