Definition of Dobsonian in US English:



  • Relating to or denoting a low-cost Newtonian reflecting telescope with large aperture and short focal length, or the simple altazimuth mount used for it.

    • ‘With Dobsonian telescopes and CCD sensors, the Earth acquired hundreds of thousands of new eyes, probing space and recording events that would have gone unnoticed by the few thousand professionals.’
    • ‘I was manning the smaller of the two telescopes that comprise the LCT, a 12.5' f/4.8 Newtonian reflector on a Dobsonian mount.’
    • ‘My existing telescope is one of these, a 13.1' f/4.5 Newtonian reflector on a Dobsonian mount.’


1980s: from the name of John Dobson, American amateur astronomer, + -ian.