- (informal) Astronomy using observations using telescopes and recording media that capture visible light.
- 1958 September 28, “Radio to Extend Astronomy's Ears”, in New York Times:
- Radio astronomy is an extension of optical astronomy in that it allows the observer to "see radiations of wave lengths far greater than those of visible light
- 1966 March 11, Time Magazine:
- Merely finding them in the first place — detecting their radio voices and photographing their odd and telltale light — was a cooperative triumph of radio and optical astronomy.
- 2006, Peter Schneider, Extragalactic astronomy and cosmology, page 25:
- Since for the atmospheric windows in the NIR one normally uses the same telescopes as for optical astronomy, we will thus not distinguish between these
- 2009 June 16, “Cosmic vision”, in Frontline:
- Because each kind of light reveals different natural phenomena, we see only a part of nature. The same is true of telescopes. Optical telescopes detect only visible light. ... Dust is the bane of optical astronomy.
- (astronomy) Astronomy using infrared, visible, and/or ultraviolet wavelengths.