What are 3 basic categories of astronomical observation?

Answer 1

Imaging, which yields photographs (images) of astronomical objects; spectroscopy, in which astronomers obtain and study spectra; and timing, which tracks how an object changes with time.

Answer 2

The three basic categories of astronomical observation are optical, radio, and space-based. Optical observations involve using telescopes to detect visible light; radio observations involve detecting radio waves from celestial objects; space-based observations are done using telescopes and satellites positioned outside Earth's atmosphere to observe different wavelengths of light.