HD 20104

HD 20104
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Camelopardalis
A
Right ascension 03h 17m 31.527s[1]
Declination +65° 39′ 30.11″[1]
Apparent magnitude (V) 7.05±0.01[1]
B
Right ascension 03h 17m 31.593s[1]
Declination +65° 39′ 30.26″[1]
Apparent magnitude (V) 7.39±0.01[1]
Characteristics
A
Spectral type A2 V[2]
U−B color index +0.06[3]
B−V color index +0.08[3]
B
Spectral type A4V[2]
Astrometry
Radial velocity (Rv)−6±2[4] km/s
Proper motion (μ) RA: −10.54 mas/yr[5]
Dec.: +5.84 mas/yr[5]
Parallax (π)5.92 ± 0.65 mas[5]
Distanceapprox. 550 ly
(approx. 170 pc)
Absolute magnitude (MV)+0.3[6]
Orbit[7]
PrimaryHD 20104 A
CompanionHD 20104 B
Period (P)350 yr
Semi-major axis (a)0.46″
Eccentricity (e)0.4
Inclination (i)135°
Longitude of the node (Ω)58°
Periastron epoch (T)2055.0
Argument of periastron (ω)
(secondary)		100°
Details
A
Mass2.46[8] M☉
B
Mass2.27[8] M☉
Other designations
BD+65°338, GC 3893, HD 20104, HIP 15309, HR 967, SAO 12686, ADS 2436, WDS J03175+6540
Database references
SIMBADThe system
A
B

HD 20104 (HR 967) is a visual binary in the northern circumpolar constellation Camelopardalis. The system has a combined apparent magnitude of 6.41,[9] making it near naked eye visibility. When resolved in a large telescope, HD 20104 appears to be a pair of 7th magnitude A-type main-sequence stars with a separation of about 0.5″.[10] Located approximately 550 light years away,[5] the system is approaching the Sun with a heliocentric radial velocity of −6 km/s.[4]

The system's stars have masses twice that of the Sun[8] and effective temperatures ranging from 8,100 to 8,700 K,[9][11] typical of stars their type. The primary radiates at 71.3 L☉[11] − over luminous for its class − and spins with a projected rotational velocity of 159 km/s.[12] HD 20104 has an age of 313 million years.[11]

  1. ^ a b c d e f Cite error: The named reference Fabricius2002 was invoked but never defined (see the help page).
  2. ^ a b Cite error: The named reference Edwards1976 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference Haupt1974 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference Wilson1953 was invoked but never defined (see the help page).
  5. ^ a b c Cite error: The named reference vL2007 was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference Heintz1998 was invoked but never defined (see the help page).
  8. ^ a b c Cite error: The named reference Cvetkovic2010 was invoked but never defined (see the help page).
  9. ^ a b Cite error: The named reference Anders2019 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference Mason2001 was invoked but never defined (see the help page).
  11. ^ a b c Cite error: The named reference Zorec2012 was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference Royer2007 was invoked but never defined (see the help page).