| • Science | • People | • Locations | • Timeline |
| Contents | ||
61 Cygni's proper motion is so great, relatively speaking, that its apparent position shifts by an amount equal to the width of the full moon in a mere 150 years.
The large proper motion, greater than that of any other star visible with the naked eye, made 61 Cygni a candidate for the determination of its distance by the method of parallax when the quality of astronomical observations first made this possible. The star therefore has the distinction of being the first star (excluding the Sun) to have its distance determined. This was accomplished by Friedrich Wilhelm Bessel in 1838 who arrived at a figure close to the currently accepted value of 11.4 light years. Subsequent observations showed that, in addition to the closeness of the star, the high proper motion was attributable to its actual velocity relative to the Sun being large and almost transverse to our line of sight to the star.
From the point of the view of the casual astronomical observer, 61 Cygni is not particularly spectacular.
Although it appears to be a single star to the naked eye, 61 Cygni is in fact a widely separated binary system, composed of two K class (orange) main sequence stars, 61 Cygni A and 61 Cygni B.
The brighter is of apparent magnitudeThe apparent magnitude m of a star, planet or other heavenly body is a measure of its apparent brightness; that is, the amount of light received from the object. Hundred times less bright (e. the same object ten times as far) corresponds to an apparent ma 5.2, the fainter 6.1. The two orbit their common barycenterThe barycenter is the center of mass of two or more bodies which are orbiting each other, and is the point around which both of them orbit. In the case where one of the two objects is much larger and more massive than the other, the barycenter will be loc in a period of 653.2 years.
An observer using 7×50 binocularsA set of binoculars (from Latin, bi "two-", and oculus "eye") is a hand-held tool used to magnify distant objects by passing the image through two adjacent series of lenses, and erecting prisms. The prisms revert the image by refracting and reflecting the can find 61 Cygni two binocular fields south-east of the bright star DenebDeneb (also known as Alpha Cygni is the brightest star in the Cygnus constellation despite being at least thirty times more distant than the others. It is or has been known by a number of other names, including Arided Aridif HR 7924 and HD 197345 . At an. An observer using larger binoculars, or a telescopeNice Observatory. A telescope is perhaps the most important astronomical tool; such technology gathers (and focuses) electromagnetic radiation. Telescopes increase the apparent angular size of objects, as well as their apparent brightness. Galileo Galilei, will be able to resolve the two components of the binary.