what are the instrumentsused to study astronomical bodies?

Answer 1

It depends on which of the bodies you're referring to. However, there are a few general points we can make about them. For the most part, astronomical bodies rarely yield much information without being magnified, so some instrument which can magnify the information is usually helpful. This is called a telescope. Also, a great deal of information is contained within the electromagnetic radiation emitted or reflected by astronomical bodies. In order to study that radiation, we need to examine the electromagnetic spectrum at multiple frequences, and we can do this using an instrument called a spectroscope.
In order to record the information we gather, we can use a camera, although other instruments exist which can also capture information.

And while all these instruments are wonderful, very little can compare to a simple set of eyes on a cold, dark, clear night.

Answer 2

Mostly telescopes, spectroscopes, and cameras.