Kuma (star)

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Double star
ν Draconis / Kuma
Ny draconis.jpg
Observation
dates equinox :  J2000.0 , epoch : J2000.0
AladinLite
Constellation Dragon
Apparent brightness  4.2 likes
Astrometry
parallax (33 ± 1) mas
distance  approx. 100 ly
(approx. 30 pc )
orbit 
period AB: ≥ 44,000 years,
Aab: 38.13 days
Major semi-axis AB: 63 ", 2 (approx. 1900 AU)
eccentricity Aab: 0.04
Individual data
Names A / ν 2 ; B / ν 1
Observation data:
Right ascension A / ν 2 17321617 h 32 m 16 s
B / ν 1 17321117 h 32 m 11 s
declination A / ν 2 2551023+ 55 ° 10 ′ 23 ″
B / ν 1 2551103+ 55 ° 11 ′ 03 ″
Apparent brightness A / ν 2 4.87 likes
B / ν 1 4.89 likes
Typing:
Spectral class A / ν 2 A4m
B / ν 1 A6 V
Physical Properties:
Dimensions A / ν 2 Aa: 2.3  M ☉ , Ab: 0.3 M ☉
B / ν 1
Other names
and catalog entries
Bayer name A:  ν 2  Draconis, B:  ν 1  Draconis
Flamsteed name A:  25 Draconis, B:  24 Draconis
Bonn survey BD + 55 ° 1945 BD + 55 ° 1944
Bright Star Catalog HR 6555 HR 6554
Henry Draper Catalog HD 159560 HD 159541
SAO catalog SAO 30450 SAO 30447
Tycho catalog TYC 3892-1621-1 [1] TYC 3892-1620-1 [2]
Hipparcos catalog HIP 85829 HIP 85819
WDS catalog WDS 17322 + 5511
Further designations: IDS 17303 + 5514

Template: Infobox double star / maintenance / single coordinates

Kuma or ν Draconis (Ny Draconis) is a triple star system in the constellation of Dragon, about 100 light years away . It is a double system, one component of which is itself a spectroscopic double star.

The double system can already be resolved in binoculars, has an angular distance of 62 ", 3 and a position angle of 312 °. These two components are almost equally bright, the component ν 2  Draconis with an apparent brightness of +4.87 may be minimally brighter is as ν 1  Draconis with 4.89 mag. The orbital period of this system is at least 44000 years. ν 2  Draconis (component A of the system) is a spectroscopic binary star with a period of 38.13 days and an eccentricity of 0.04. The The main component Aa is a metal line star of the spectral class A4m. Ν 2  Draconis, the component B, belongs to the spectral class A6 V.

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