Kappa Draconis

Kappa Draconis
Location of κ Draconis (circled) near the center
Observation data
Epoch J2000      Equinox J2000
Constellation Draco
Right ascension 12h 33m 28.94206s[1]
Declination +69° 47′ 17.6331″[1]
Apparent magnitude (V) 3.82[2]
Characteristics
Spectral type B6 IIIe[3]
U−B color index −0.61[2]
B−V color index −0.11[2]
Astrometry
Radial velocity (Rv)−11.4[4] km/s
Proper motion (μ) RA: −58.162[1] mas/yr
Dec.: +11.802[1] mas/yr
Parallax (π)7.1387 ± 0.3291 mas[1]
Distance460 ± 20 ly
(140 ± 6 pc)
Absolute magnitude (MV)−1.95 + 2.4[5]
Orbit[5]
Period (P)61.5496 ± 0.0058 d
Semi-major axis (a)0.487 ± 0.021 au
Eccentricity (e)0
Inclination (i)130.0 ± 3.4°
Longitude of the node (Ω)118.0 ± 1.3°
Semi-amplitude (K1)
(primary)		6.90±0.15 km/s
Details
κ Dra A
Mass3.65 ± 0.48[5] M☉
Radius5.85 ± 0.18[5] R☉
Luminosity1178 ± 151[5] L☉
Surface gravity (log g)3.5[6] cgs
Temperature13982 ± 392[5] K
Metallicity [Fe/H]−0.65[7] dex
Rotational velocity (v sin i)200 ± 12[5] km/s
κ Dra B
Mass0.426 ± 0.043[5] M☉
Radius0.69 ± 0.07[5] R☉
Luminosity33 ± 17[5] L☉
Temperature16700 ± 2000[5] K
Rotational velocity (v sin i)35 ± 10[5] km/s
Other designations
κ Dra, 5 Dra, BD+70°703, FK5 472, HD 109387, HIP 61281, HR 4787, SAO 7593[8]
Database references
SIMBADdata

Kappa Draconis, Latinized from κ Draconis, is a blue giant star located in the northern circumpolar constellation of Draco. At an apparent magnitude of 3.88, it is barely visible to the naked eye when artificial lighting from cities is present. Nevertheless, it is a powerful star, approximately five time as massive as the Sun. It is about 460 light-years away, and is 1,400 times brighter than the Sun.

The star is currently located at declination +69° 47′ 18″ (right ascension 12h 33m 29.0s), but due to the effects of precession, Kappa Draconis was the nearest star to the north celestial pole visible to the naked eye from 1793 BC to approximately 1000 BC, though it was 6° removed from perfect alignment, making it only an approximate pole star, similar to the roughly 7° variance from perfect alignment of the much brighter (magnitude 2.08) star Kochab, at the same time during Earth's precession.[citation needed]

  1. ^ a b c d e Cite error: The named reference GaiaDR2 was invoked but never defined (see the help page).
  2. ^ a b c Cite error: The named reference aj76_1058 was invoked but never defined (see the help page).
  3. ^ Cite error: The named reference mnras309_1_221 was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference gcsrv was invoked but never defined (see the help page).
  5. ^ a b c d e f g h i j k l Cite error: The named reference Klement was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference Saad2004 was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).