Concept
Stellar parallax
Overview
Stellar parallax is the apparent shift of position (parallax) of any nearby star (or other object) against the background of distant stars. By extension, it is a method for determining the distance to the star through trigonometry, the stellar parallax method. Created by the different orbital positions of Earth, the extremely small observed shift is largest at time intervals of about six months, when Earth arrives at opposite sides of the Sun in its orbit, giving a baseline (the shortest side of the triangle made by a star to be observed and two positions of Earth) distance of about two astronomical units between observations. The parallax itself is considered to be half of this maximum, about equivalent to the observational shift that would occur due to the different positions of Earth and the Sun, a baseline of one astronomical unit (AU).
Stellar parallax is so difficult to detect that its existence was the subject of much debate in astronomy for hundreds of years. Thomas Henderson, Friedrich Georg Wilhelm von Struve, and Friedrich Bessel made the first successful parallax measurements in 1832–1838, for the stars Alpha Centauri, Vega, and 61 Cygni.
Overview adapted from Wikipedia (CC BY-SA 4.0; see the article history for authors).
Possible passages
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For this star, the parallax π = ·014″, _e_ = ·005, _u₀_ = 110 _km_/sec, T = 3·96, Δ > 65 light-years, _k_ is < ·002. For an experimental proof, see a paper by C. Majorana. Phil. Mag., Vol. 35, p. 163. Note 10. Rest-density of Electricity. If ρ is the volume density in a moving system then ρ√(1 - _u²_) is the corresponding quantity in the corresponding volume in the fixed system, that is, in the system at rest, and…
Albert Einstein, The Principle of Relativity
States what Stellar parallax is.
8. The eighth is named vespertine location in the mid-heaven; when the star is on the meridian, either above or below the earth, while the Sun is placed on the occidental horizon. Of this aspect, one kind is called a visible vespertine location in the mid-heaven; when the star is found there immediately after sunset: another is the precise vespertine location in the mid-heaven; when the star is found there at the…
Ptolemy, Ptolemy's Tetrabiblos
States what Stellar parallax is.
The which adorned and embellished as it was by Eudoxus, Aratus who had no knowledge of astronomy, but a certain poetical faculty, many years afterwards extolled in his verses. The mechanism of this sphere, however, on which the motions of the sun, moon, and those five stars which are called wandering and irregular, are shown; could not be illustrated on that solid sphere. But what appeared very admirable in this…
Marcus Tullius Cicero, The republic of Cicero
States what Stellar parallax is.
Philosophers who discussed Stellar parallax
Related ideas
Place in the tradition
Part of Universe.