How is the distance from the Earth to the nearest star calculated?

The nearest star besides the Sun.How is the distance from the Earth to the nearest star calculated?Parallax is the most accurate method for nearby stars. The star is observed and its position recorded as compared to background stars. Then six months later, it is observed again and the star appears to have "shifted" against the background due to the stereoscopic effect. Since we know the diameter of earth's orbit, the distance to the star can be calculated based on the amount of parallax.How is the distance from the Earth to the nearest star calculated?Distance to nearby stars are calculated using stellar motion parallax. Since the Earth rotates around our sun, and stars are (esentially) motionless against a cosmic background, you can measure where star A vs. background stars is at time point, and measure again when the Earth has moved to a different place in it's orbit. By finding out the difference in angle the star's apparant motion has changed and how far the Earth has moved, you have what ammounts to a triangle: an angle and an opposite length which you can use to solve for distance using some trigonometry.How is the distance from the Earth to the nearest star calculated?A really long tape measure.How is the distance from the Earth to the nearest star calculated?
Parallax. This is extensively documented, and has been asked (and answered) in this very forum half a dozen times in the last week.



The first successful measurements of stellar parallax were for two stars that astronomers thought might be close by: Vega, because it is bright, and 61 Cygni, because it has high proper motion. I assume they didn't try Sirius (which is closer than either, and much brighter than Vega) because it is visible a relatively short part of the year from northern observatories.



It turns out that the parallax of Alpha Centauri had already been measured (it too is bright, and we now know it to be close by), but the results had not been published because they were thought to be in error.