Difference between revisions of "61 Cygni"
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==The Stars== | ==The Stars== | ||
| − | Although barely visual to the naked eye and appearing as a single star, 61 Cygni is actually a binary star, each which orbit around a common barycenter only every 659 years. The average distance of the pair from each other is 86 AUs, but the large orbital eccentricity means the stars approach as close as 44 AUs and as distant as 124 AUs during their orbit<ref name="61Cygni">http://solstation.com/stars/61cygni2.htm</ref>. | + | Although barely visual to the naked eye and appearing as a single star, 61 Cygni is actually a binary star, each which orbit around a common barycenter only every 659 years. The average distance of the pair from each other is 86 AUs, but the large orbital eccentricity means the stars approach as close as 44 AUs at periastron and are as distant as 124 AUs at apastron during their orbit<ref name="61Cygni">http://solstation.com/stars/61cygni2.htm</ref>. |
Both stars are K class sub-dwarfs, 61 Cygni A is the slightly larger ''primary'' with 70 percent of our sun's mass, 72 percent of its diameter, but only some 8.5 percent of its luminosity. 61 Cygni B, the ''secondary'' is only 3some 63 percent of our sun's mass, 67 percent of its diameter, and only half as luminous as 61 Cygni A, or about 4 percent as much as our sun<ref name="61Cygni">http://solstation.com/stars/61cygni2.htm</ref>. | Both stars are K class sub-dwarfs, 61 Cygni A is the slightly larger ''primary'' with 70 percent of our sun's mass, 72 percent of its diameter, but only some 8.5 percent of its luminosity. 61 Cygni B, the ''secondary'' is only 3some 63 percent of our sun's mass, 67 percent of its diameter, and only half as luminous as 61 Cygni A, or about 4 percent as much as our sun<ref name="61Cygni">http://solstation.com/stars/61cygni2.htm</ref>. | ||
Revision as of 16:26, June 18, 2009
61 Cygni, also called 61 Cygni 2, Bessel's Star, or Piazzi's Flying Star, is a binary star located some 11.6 light years from our solar system in the constellation of Cygnus near the star Deneb. The star is famous for it's unusually large proper motion and for being the first star outside our own to be successfully measured using stellar or trigonometric parallax.
History
The first discovery of the star was in 1792 by Giuseppe Piazzi[1], who later demonstrated the star's unusually large proper motion. However the star did not become significant in history until 1838, when German mathematician and astronomer Friedrich Wilhelm Bessel who calculated it's distance using trigonometric parallax, the first star outside our own system to be measured in such a way[2]. The distance he calculated was so enormous, that the distance could best be adequately explained in the amount of years it took light to reach us from the binary pair.
The Stars
Although barely visual to the naked eye and appearing as a single star, 61 Cygni is actually a binary star, each which orbit around a common barycenter only every 659 years. The average distance of the pair from each other is 86 AUs, but the large orbital eccentricity means the stars approach as close as 44 AUs at periastron and are as distant as 124 AUs at apastron during their orbit[3].
Both stars are K class sub-dwarfs, 61 Cygni A is the slightly larger primary with 70 percent of our sun's mass, 72 percent of its diameter, but only some 8.5 percent of its luminosity. 61 Cygni B, the secondary is only 3some 63 percent of our sun's mass, 67 percent of its diameter, and only half as luminous as 61 Cygni A, or about 4 percent as much as our sun[3].
Planetary Companions
Despite numerous claims, no sub-stellar objects have been independently confirms as orbiting either star. An Earth like world where water could exist in a liquid state would be centered around 0.39 AU around 61 Cygni A and 0.34 AU around 61 Cygni B respectively[3].
