61 Cygni
Sign in to saveAlso known as Bessel's star, Piazzi's Flying Star, Struve 2758, * 61 Cyg, 61 Cyg, HD 201091, HD 201092
binary star in the Cygnus constellation
Key facts
- Constellation
- Cygnus
- Right ascension
- 21 06 53.9396
- Declination
- +38 ° 44 ′ 57.902 ″
- Evolutionary stage
- main sequence
- Spectral type
- K5V
- U b color index
- +1.155
- B v color index
- +1.139
- Variable type
- BY Dra
via Wikipedia infobox
Wikidata facts
- Instance of
- star
- Named after
- Friedrich Bessel
- Constellation
- Cygnus
- Distance from Earth
- 3.5
- Radius
- 0.665
- Mass
- 0.7
- Image
- 61 cygni map.png
Show 14 more facts
Sources (10)
via Wikidata · CC0
~16 min read
Encyclopedic overview
61 Cygni /ˈsɪɡni/ is a binary star system in the northern constellation Cygnus, consisting of a pair of K-type dwarf stars that orbit each other in a period of about 659 years. Of apparent magnitude 5.20 and 6.05, respectively, they can be seen with binoculars in city skies or with the naked eye in rural areas without light pollution.
61 Cygni first attracted the attention of astronomers when its large proper motion was first demonstrated by Giuseppe Piazzi in 1804. In 1838, Friedrich Bessel measured its distance from Earth at about 10.4 light-years, very close to the actual value of about 11.4 light-years; this was the first distance estimate for any star other than the Sun, and the first star to have its stellar parallax measured. Among all stars or stellar systems listed in the latest Gaia catalogues, 61 Cygni has the sixth-highest proper motion, and the highest among all naked-eye visible stars.
Excerpted from Wikipedia’s “61 Cygni” article, available under the CC BY-SA 4.0 licence.