Aljanah

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Double star
Aljanah
AladinLite
Observation
dates equinox :  J2000.0 , epoch : J2000.0
Constellation swan
Right ascension 20 h 46 m 12.7 s
declination + 33 ° 58 ′ 13 ″
Apparent brightness 2.48 likes
Typing
B − V color index (1.04) 
U − B color index (0.85) 
R − I index (0.54) 
Spectral class K0 III
Astrometry
Radial velocity (−12.41 ± 0.12) km / s
parallax (45.26 ± 0.53)  mas
distance (72.1 ± 0.8)  ly
(22.1 ± 0.3)  pc
Proper movement 
Rec. Share: (365.95 ± 1.78)  mas / a
Dec. portion: (308.79 ± 1.77)  mas / a
Physical Properties
Other names
and catalog entries
Bayer name ε Cygni
Flamsteed name 53 Cygni
Bonn survey BD + 33 ° 4018
Bright Star Catalog HR 7949 [1]
Henry Draper Catalog HD 197989 [2]
Gliese catalog GJ 806.1 [3]
Hipparcos catalog HIP 102488 [4]
SAO catalog SAO 70474 [5]
Tycho catalog TYC 2695-4139-1 [6]
2MASS catalog 2MASS J20461266 + 3358128 [7]
Other names FK5  780 • GJ 9707 • Gienah • Aljanah • Gienah Cygni

Aljanah , Bayer name ε Cygni (Epsilon Cygni), also outdated "Gienah", is a 72  light-years distant star in the constellation Swan of the spectral class K0 with an apparent magnitude of 2.5 mag. The star is probably the brightest component of a double or multiple star system. Little is known about the companion or companions.

The proper name Gienah ( Arabic جناح, DMG ğanāḥ  'wing') is historical. To distinguish it from the star of the same name in the constellation Corvus, it is also called Gienah Cygni . On the recommendation of the IAU 2017, the name Gienah should only be used for Gamma Corvi, while for Epsilon Cygni the Latin transcription Aljanah, which differs from it, removes the ambiguity in the non-Arabic language area.

See also

Web links

Individual evidence

  1. ↑ a b c d e f g h eps Cyg. In: SIMBAD . Center de Données astronomiques de Strasbourg , accessed October 29, 2018 .
  2. ^ Entry in the Hipparcos catalog at VizieR
  3. ^ IAU: Naming Stars
  4. ↑ Stefan Parsch: Xamidimura and Zubenelhakrabi: 86 new star names assigned , on: n-tv online, from December 15, 2017