51 Aquarii

51 Aquarii
Observation data
Epoch J2000      Equinox J2000
Constellation Aquarius
Right ascension 22h 24m 06.88433s[1]
Declination –04° 50′ 13.2692″[1]
Apparent magnitude (V) 5.78 (6.45 + 6.63)[2]
Characteristics
Spectral type A0 V[3] + A0[2]
U−B color index –0.11[4]
B−V color index –0.04[4]
Astrometry
Radial velocity (Rv)+6[5] km/s
Proper motion (μ) RA: +26.90[1] mas/yr
Dec.: –7.35[1] mas/yr
Parallax (π)8.04 ± 0.63 mas[1]
Distance410 ± 30 ly
(124 ± 10 pc)
Orbit[6]
Period (P)145.07±1.85 yr
Semi-major axis (a)0.402±0.003″
Eccentricity (e)0.702±0.003
Inclination (i)161.4±0.7°
Longitude of the node (Ω)113.5±3.0°
Periastron epoch (T)1987.66±0.05
Argument of periastron (ω)
(secondary)		296.9±3.0°
Details
51 Aqr A
Mass2.80±0.10[7] M☉
Luminosity88.2+14.8
−14.2[7] L☉
Temperature10,328±71[7] K
Rotational velocity (v sin i)91[7] km/s
Other designations
51 Aqr, BD−05°5780, HD 212404, HIP 110578, HR 8533, SAO 146067, WDS J22241-0450[8]
Database references
SIMBADdata

51 Aquarii is a binary star[2] system located around 410[1] light years away from the Sun in the equatorial constellation of Aquarius. 51 Aquarii is its Flamsteed designation. It is visible to the naked eye as a dim, yellow-white hued star with a combined apparent visual magnitude of 5.78.[4] The system is moving further from the Earth with a heliocentric radial velocity of +6 km/s.[5]

The dual nature of this system was discovered by S. W. Burnham in 1873 with a 6 inches (15 cm) Alvan Clark refractor.[9] The pair orbit each other with a period of 145 years and a large eccentricity of 0.7.[6] The magnitude 6.45[2] primary, designated component A, is an A-type main sequence star with a stellar classification of A0 V.[3] It has a high rate of rotation with a projected rotational velocity of 91 km/s.[10] The secondary component has a matching class of A0 with a visual magnitude of 6.63.[2] It has an effective temperature of 10,238 K.

  1. ^ a b c d e f Cite error: The named reference aaa474_2_653 was invoked but never defined (see the help page).
  2. ^ a b c d e Cite error: The named reference Eggleton2008 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference aj74_375 was invoked but never defined (see the help page).
  4. ^ a b c Cite error: The named reference aass34_1 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference gcrv1953 was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference Tokovinin2015 was invoked but never defined (see the help page).
  7. ^ a b c d Cite error: The named reference zorec2012 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).
  9. ^ Cite error: The named reference Docobo2007 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference aaa463_2_671 was invoked but never defined (see the help page).