because they are filled with hot gas
They emit: gamma rays, radio waves, and x-rays. Some stars emit T.V. rays
Chandra X-ray Observatory detects X-rays, which are a type of electromagnetic wave with higher energy and shorter wavelength than visible light. X-rays are emitted by extremely hot and high-energy objects in the universe, such as black holes, neutron stars, and supernova remnants.
Different types of electromagnetic waves provide different kinds of information. Specifically, black holes will emit large amounts of x-rays.
CRT and plasma TVs emit x-rays, which can be hazardous.
yes, some do.
yes, some do.
yes, some do.
There are plenty of celestial bodies that emit xrays - while others scatter, reflect, or alter the energy of electromagnetic radiation into the x-ray range. Sources that emit x-rays include pulsars or neutron stars, the accretion disks of black holes, stars - particularly ones with certain types of companions, stellar remnants such as from supernovae, entire galaxies (with and without active nuclei) and to some extent, even the universe as a whole; though some of this is generally attributed to mechanisms which heat gas. There are even x-ray sources within the solar system, including the Moon, since not all of its observed x-ray emission is simply reflected from the Sun.
Black holes do not emit light, so black holes can not be seen this way. But black holes emit X-rays, but stars are not hot enough to emit X-rays. When black holes suck up stars, energy goes to the black hole, and come out as X-rays.
Black holes can emit X-rays when matter falls into them and gets heated up to very high temperatures, producing intense radiation that includes X-rays. This process is known as accretion, where the matter spirals into the black hole's gravitational pull and releases energy in the form of X-rays.
Stars can emit various forms of radiation, including ultraviolet, X-rays, and gamma rays. Sun-like stars emit primarily visible light and some ultraviolet radiation. More massive stars can also emit X-rays and gamma rays.
A gas heated to millions of degrees would emit X-rays.