Adrien Auzout (28 January 1622 – 23 May 1691) was a French astronomer.
Astrometry is the branch of astronomy that involves precise measurements of the positions and movements of stars and other celestial bodies.
Augustin-Jean Fresnel (10 May 178814 July 1827) was a French civil engineer and physicist whose research in optics led to the almost unanimous acceptance of the wave theory of light, excluding any remnant of Newton's corpuscular theory, from the late 1830s until the end of the 19th century.
Sir Christopher Wren PRS FRS (–) was an English anatomist, astronomer, geometer, and mathematician-physicist, as well as one of the most highly acclaimed English architects in history.
Great refractor refers to a large telescope with a lens, usually the largest refractor at an observatory with an equatorial mount.
A heliometer (from Greek ἥλιος hḗlios "sun" and measure) is an instrument originally designed for measuring the variation of the sun's diameter at different seasons of the year, but applied now to the modern form of the instrument which is capable of much wider use.
McMillin Observatory is an astronomical observatory built around 1895, named after Emerson McMillin and run by the Ohio State University.
A micrometer, sometimes known as a micrometer screw gauge, is a device incorporating a calibrated screw widely used for precise measurement of components in mechanical engineering and machining as well as most mechanical trades, along with other metrological instruments such as dial, vernier, and digital calipers.
A reticle, or reticule, also known as a graticule, is a pattern of fine lines or markings built into the eyepiece of a sighting device, such as a telescopic sight in a telescope, a microscope, or the screen of an oscilloscope, to provide references during visual examination.
Robert Thorburn Ayton Innes FRSE FRAS (10 November 1861 – 13 March 1933) was a Scottish astronomer best known for discovering Proxima Centauri in 1915, and numerous binary stars.
Stellar parallax is the apparent shift of position of any nearby star (or other object) against the background of distant objects.