noun
radio astronomy
The branch of astronomy that studies celestial objects at radio frequencies.
電波天文学は、宇宙からの電波を観測する学問です。
Radio astronomy is the study of observing radio waves from space.
天文学 is general astronomy; 電波天文学 specifically studies radio waves from celestial objects.
Compound of 電波 (radio wave) + 天文学 (astronomy).