61 Cygni

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Double star
61 Cygni
Location of the star system 61 Cygni
Location of the star system 61 Cygni
Observation
dates equinoxJ2000.0 , epoch : J2000.0
AladinLite
Constellation swan
Apparent brightness  4.8 likes
Astrometry
Radial velocity (−65.74 ± 0.09) km / s /
(−64.07 ± 0.08) km / s
parallax (285.95 ± 0.10) mas /
(286.15 ± 0.06) mas
distance  11.40 ly
(3.5 pc )
Proper movement :
Rec. Share: 4164.17 ± 0.19 mas / a /
4105.79 ± 0.09 mas / a
Dec. portion: 3249.99 ± 0.25 mas / a /
3155.76 ± 0.10 mas / a
orbit 
period (659 ± 17) a
Major semi-axis 24.4 ″ ± 0.7 ″
eccentricity 0.48 ± 0.03
Orbit inclination 54 ° ± 3 °
Argument of the node 176 ° ± 1 °
Individual data
Names A ; B.
Observation data:
Right ascension A. 21 h 06 m 53.940 s
B. 21 h 06 m 55.264 s
declination A. 2384457.897+ 38 ° 44 ′ 57,897 ″
B. 2384431.362+ 38 ° 44 ′ 31,362 ″
Apparent brightness A. 5.21 mag
B. 6.03 mag
Typing:
Spectral class A. K5 V
B. K7 V
B − V color index A. +1.139
B. +1.320
U − B color index A. +1.155
B. +1.242
Physical Properties:
rel. Brightness
(G-band)
A. 4.72 ± 0.01 mag
B. 5.42 ± 0.01 mag
rel. Brightness
(J-band)
A. 3.12 mag
B. 3.55 mag
Absolute vis.
Brightness
M vis
A. 7.49 likes
B. 8.31 mag
Dimensions A. (0.708 ± 0.053) M
B. (0.657 ± 0.057) M
radius A. (0.702 ± 0.068) R
B. (0.644 ± 0.067) R
Luminosity A. 0.0861 L
B. 0.0405 L
Effective temperature A. 4,350 K
B. 4,060 K
Metallicity [Fe / H] A. −0.20
B. −0.27
Rotation time A. 18.2 d
B. 17 d
Age approx. 6.1 billion years
Other names
and catalog entries
Flamsteed name 61 Cygni
SAO catalog SAO 70919 [1]
Bonn survey BD + 38 ° 4343 BD + 38 ° 4344
Bright Star Catalog HR 8085 HR 8086
Henry Draper Catalog HD 201091 HD 201092
Tycho catalog TYC 3168-2800-1 [2] TYC 3168-2798-1 [3]
Hipparcos catalog HIP 104214 HIP 104217
WDS catalog WDS J21069 + 3845
Further designations: GJ 820, Struve 2758, FK5 793
  LHS 62, V1803 Cygni LHS 63

Template: Infobox double star / maintenance / single coordinates

61 Cygni is a double star in the constellation Swan . 61 Cygni is 11 light-years away and is one of the stars closest to the sun . It can be resolved into single stars with prism binoculars .

The main star has an apparent magnitude of +5.21 mag and belongs to the spectral class K5 V. It bears the designations HR 8085, HD 201091 or SAO 70919 in various star catalogs .

The +6.03 mag bright companion star belongs to the spectral class K7 V. It also has the designations HD 201092 and BD  + 38 ° 4344.

Astronomical meaning

61 Cygni was the first fixed star whose distance was measured directly by determining its parallax , namely in the years 1837 and 1838 by the astronomer Friedrich Wilhelm Bessel at the Königsberg observatory . At the time, Bessel calculated that “light will not reach us from this star for 9¼ years”. (Quoted from Humboldt, Kosmos, p. 43, Eichborn Edition 2004).

Self-movement of 61 Cygni in a series of recordings that were taken every year

According to modern measurements, its parallax is 0.29 ", and Bessel had already suspected its short distance due to the large intrinsic movement of over 5" annually (see high-speed runner ). Bessel's result was on average 0.31 "± 0.02".

Position of the companion star of 61 Cygni

year Angular distance Position angle
1990 29.7 148 degrees
2010 30.8 ″ 152 degrees

location

Location of Cygni 61 in the constellation Swan between the stars Cygni 65 ( ) and Cygni 58 ( )

The Bessel star Cygni 61 is located south of the brightest star Deneb ( or Cygni 50, 1.25 m ) in the tail and east of the third brightest star Gienah ( or Cygni 53, 2.48 m ) in the right (southern) wing of the constellation Swan . It is located a little to the right of the connecting line on a third of the route from Cygni 65 ( , 3.73 m ) to Cygni 58 ( , 3.94 m ).

North of Cygni 61 is the North American Nebula (NGC 7000).

61 Cygni in literature and in the media

The science fiction novel Chasm City by Alastair Reynolds initially takes place on a fictional planet Sky's Edge orbiting the star 61 Cygni A.

In the Star Trek universe , 61 Cygni is considered the home of the Tellarite people and is also known as Tellar. The secondary work The Worlds of the Federation establishes this connection for the first time.

Size comparison between the sun, 61 Cygni A (below) and 61 Cygni B (above)

Web links

Commons : 61 Cygni  - Collection of images, videos and audio files

Individual evidence

  1. a b c d e f 61 Cyg A. In: SIMBAD . Center de Données astronomiques de Strasbourg , accessed March 16, 2019 .
  2. a b c d e f 61 Cyg B. In: SIMBAD. Center de Données astronomiques de Strasbourg, accessed March 16, 2019 .
  3. a b P. E. Kervella, F. Arenou, F. Mignard, F. Thévenin: Stellar and substellar companions of nearby stars from Gaia DR2. Binarity from proper motion anomaly . In: Astronomy & Astrophysics . 623, p. A72. arxiv : 1811.08902 . bibcode : 2019A & A ... 623A..72K . doi : 10.1051 / 0004-6361 / 201834371 .
  4. FW Bessel, measurement of the distance of the 61st star in the constellation of the swan , in Popular lectures on scientific subjects , No. VII, pp.208-268, published by H. Schumacher, Perthes & Besser, Hamburg 1848