What kind of telescopes are used to observe black holes?

Answer 1

You can't really "observe" a black hole. About the best you can do is look for their effects on their immediate environment, and one of the best tools for that is an X-ray telescope... matter falling into the black hole releases a lot of energy, and some of that comes out as X-rays.

Answer 2

Nothing can go directly out of a black hole; however, it should still be possible to observe the black hole. All of the following methods, except for the first, are related to the black hole's gravity.

1. A black hole should emit a very weak Hawking radiation. Currently we don't have the technology to observe this; this hypothetical radiation would be very, very weak. The Hawking radiation is created near the black hole border (the event horizon), outside of it, due to certain quantum-mechanical effects.

2. If an object rotates around another, invisible object, this is often quite obvious. A common case is a double star, where one of the components is no longer an active star, but has turned into a black hole.

3. Matter falling into the black hole will emit strong radiation - X-rays. This happens outside the event horizon; once matter is inside the event horizon, nothing can be seen.

4. Black holes tend to have accretion disks - disks of matter surrounding the black hole. The gas in these accretion disks heats up, due to interactions between the gas molecules, and emit radiation.

5. For reasons not yet entirely understood, the matter in these accretion disks gets emitted in two directions along the axis from the black hole; in galactic black holes, matter will be emitted in jets at almost the speed of light.

6. Microlensing. The black hole will change the direction of light that comes to us, from the other side, if it gets near the black hole.

Answer 3

An astronomer uses a solar telescope to look at the sun. Dobsonian telescopes are designed to be low cost and portable. These are just some of the types of telescopes an astronomer uses in his or her job.