Question: What year was the phenomenon used to explain the color of binary stars described?

full_context: Document 1: Photoacoustic Doppler effect: The photoacoustic Doppler effect, as its name implies, is one specific kind of Doppler effect, which occurs when an intensely modulated light wave induces a photoacoustic wave on moving particles with a specific frequency. The observed frequency shift is a good indicator of the velocity of the illuminated moving particles. A potential biomedical application is measuring blood flow.
Document 2: Augustin-Jean Fresnel: Augustin-Jean Fresnel ( ; ] ; 10 May 1788 – 14 July 1827) was a French engineer and physicist who contributed significantly to the establishment of the theory of wave optics. Fresnel studied the behaviour of light both theoretically and experimentally.
Document 3: Oberth effect: In astronautics, a powered flyby, or Oberth maneuver, is a maneuver in which a spacecraft falls into a gravitational well, and then accelerates when its fall reaches maximum speed. The resulting maneuver is a more efficient way to gain kinetic energy than applying the same impulse outside of a gravitational well. The gain in efficiency is explained by the Oberth effect, wherein the use of an engine at higher speeds generates greater mechanical energy than use at lower speeds. In practical terms, this means that the most energy-efficient method for a spacecraft to burn its engine is at the lowest possible orbital periapse, when its orbital velocity (and so, its kinetic energy) is greatest. In some cases, it is even worth spending fuel on slowing the spacecraft into a gravity well to take advantage of the efficiencies of the Oberth effect. The maneuver and effect are named after Hermann Oberth, the Austro-Hungarian-born German physicist and a founder of modern rocketry, who first described them in 1927.
Document 4: Daniel Bernoulli: Daniel Bernoulli FRS ( ; ] ; 8 February 1700 – 17 March 1782) was a Swiss mathematician and physicist and was one of the many prominent mathematicians in the Bernoulli family. He is particularly remembered for his applications of mathematics to mechanics, especially fluid mechanics, and for his pioneering work in probability and statistics. His name is commemorated in the Bernoulli's principle, a particular example of the conservation of energy, which describes the mathematics of the mechanism underlying the operation of two important technologies of the 20th century: the carburetor and the airplane wing.
Document 5: Doppler effect: The Doppler effect (or the Doppler shift) is the change in frequency or wavelength of a wave for an observer who is moving relative to the wave source. It is named after the Austrian physicist Christian Doppler, who described the phenomenon in 1842.
Document 6: Theory of Colours: Theory of Colours (German: "Zur Farbenlehre") is a book by Johann Wolfgang von Goethe about the poet's views on the nature of colours and how these are perceived by humans. Published in 1810, it contains detailed descriptions of phenomena such as coloured shadows, refraction, and chromatic aberration.
Document 7: Franz–Keldysh effect: The Franz–Keldysh effect is a change in optical absorption by a semiconductor when an electric field is applied. The effect is named after the German physicist Walter Franz and Russian physicist Leonid Keldysh (nephew of Mstislav Keldysh).
Document 8: Cherenkov radiation: Cherenkov radiation, also known as Vavilov–Cherenkov radiation (named after Sergey Vavilov and Pavel Cherenkov), is electromagnetic radiation emitted when a charged particle (such as an electron) passes through a dielectric medium at a speed greater than the phase velocity of light in that medium. The characteristic blue glow of an underwater nuclear reactor is due to Cherenkov radiation. It is named after Soviet scientist Pavel Alekseyevich Cherenkov, the 1958 Nobel Prize winner who was the first to detect it experimentally. A theory of this effect was later developed within the framework of Einstein's special relativity theory by Igor Tamm and Ilya Frank, who also shared the Nobel Prize. Cherenkov radiation had been theoretically predicted by the English polymath Oliver Heaviside in papers published in 1888–89.
Document 9: Brownian noise: In science, Brownian noise (   ), also known as Brown noise or red noise, is the kind of signal noise produced by Brownian motion, hence its alternative name of random walk noise. The term "Brown noise" comes not from the color, but after Robert Brown, the discoverer of Brownian motion. The term "red noise" comes from the "white noise"/"white light" analogy; red noise is strong in longer wavelengths, similar to the red end of the visible spectrum.
Document 10: Donald B. Campbell: Donald B. Campbell is an Australian-born astronomer and Professor of Astronomy at Cornell University. Prior to joining the Cornell faculty he was Director of the Arecibo Observatory in Puerto Rico for seven years. Campbell's research work is in the general area of planetary studies with a concentration on the radio-wavelength-scattering properties of planets, planetary satellites, and small bodies. His work includes studies of Venus, the Moon, the Galilean satellites of Jupiter, Titan, as well as comets and asteroids. Campbell observed near-Earth asteroid 433 Eros, which was the first asteroid detected by the Arecibo Observatory radar system.
Document 11: Relativistic Doppler effect: The relativistic Doppler effect is the change in frequency (and wavelength) of light, caused by the relative motion of the source and the observer (as in the classical Doppler effect), when taking into account effects described by the special theory of relativity.
Document 12: Christian Doppler: Christian Andreas Doppler ( ; ] ; 29 November 1803 – 17 March 1853) was an Austrian mathematician and physicist. He is celebrated for his principle — known as the Doppler effect — that the observed frequency of a wave depends on the relative speed of the source and the observer. He used this concept to explain the color of binary stars.
Document 13: O'Connell effect: The O'Connell effect is an asymmetry in the photometric light curve of certain close eclipsing binary stars. It was named after the astronomer D. J. K. O'Connell, SJ of Riverview College in New South Wales who in 1951 studied this phenomenon and distinguished it from the so-called periastron effect described by earlier authors, as it does not necessarily appear near the periastron, when tidal effects and an increase in mutual radiation may cause an increase in luminosity.
Document 14: Phi phenomenon: The phi phenomenon is the optical illusion of perceiving a series of still images, when viewed in rapid succession, as continuous motion. Max Wertheimer, one of the three founders of Gestalt psychology, defined this phenomenon in 1912. The phi phenomenon and persistence of vision together formed the foundation of Hugo Münsterberg's theory of film and are part of the process of motion perception.
Document 15: Time dilation: According to the theory of relativity, time dilation is a difference in the elapsed time measured by two observers, either due to a velocity difference relative to each other, or by being differently situated relative to a gravitational field. As a result of the nature of spacetime, a clock that is moving relative to an observer will be measured to tick slower than a clock that is at rest in the observer's own frame of reference. A clock that is under the influence of a stronger gravitational field than an observer's will also be measured to tick slower than the observer's own clock.
ground_truth: 1842