EZ Aquarii

EZ Aquarii A/B/C
EZ Aquarii star system
EZ Aquarii Star System (simulation).
Credit: SpaceEngine/Bob Trembley
Observation data
Epoch J2000      Equinox J2000
Constellation Aquarius
Right ascension 22h 38m 33.73s[1]
Declination −15° 17′ 57.3″[1]
Apparent magnitude (V) 12.38[2] (13.03/13.27/15.07)[3]
Characteristics
Spectral type M5 V[3]
B−V color index +1.96[4]
Variable type Flare star + BY Dra[5]
Astrometry
Radial velocity (Rv)−59.9[6] km/s
Proper motion (μ) RA: +2314[7] mas/yr
Dec.: +2295[7] mas/yr
Parallax (π)293.6 ± 0.9 mas[8]
Distance11.11 ± 0.03 ly
(3.41 ± 0.01 pc)
Absolute magnitude (MV)14.75[9] (15.33/15.58/17.37)[3]
Orbit[10]
PrimaryEZ Aquarii AC
CompanionEZ Aquarii B
Period (P)2.2506±0.0033 yr
Semi-major axis (a)0.346±0.004″
Eccentricity (e)0.437±0.007
Inclination (i)112.4±0.5°
Longitude of the node (Ω)162.1±0.4°
Periastron epoch (T)1987.236 ± 0.014
Argument of periastron (ω)
(secondary)		−17.7±1.1°
Details
EZ Aquarii A
Mass0.1187±0.0011[8] M☉
Radius0.175[11] R☉
Luminosity0.00078[8] L☉
EZ Aquarii C
Mass0.0930±0.0008[8] M☉
Luminosity0.00012[8] L☉
EZ Aquarii B
Mass0.1145±0.0012[8] M☉
Radius0.21±0.04[8] R☉
Temperature2650±200[8] K
Other designations
EZ Aqr, GJ 866[12], G 156-031, L 789-6, LHS 68, GCTP 5475.00[13]
Database references
SIMBADdata
EZ Aquarii is located in the constellation Aquarius.
EZ Aquarii is located in the constellation Aquarius.
EZ
Location of EZ Aquarii in the constellation Aquarius

EZ Aquarii is a triple star system 11.1 light-years (3.4 parsecs) from the Sun in the constellation Aquarius within the Milky Way. It is also known as Luyten 789-6, Gliese 866 and LHS 68. It is a variable star showing flares as well as smaller brightness changes due to rotation. The aggregate mass of the system is 0.3262±0.0018 solar masses.[8] All three seem to have masses close to the hydrogen burning mass limit.[10]

William E. Kunkel announced that Luyten 789-6 was a flare star in 1972, after having observed seven flares.[14] It was given its variable star designation, EZ Aquarii, in 1978.[15]

The configuration of the inner binary pair may permit a circumbinary planet to orbit near their habitable zone, however no exoplanets have yet been observed.[16] EZ Aquarii is approaching the Solar System and, in about 32,300 years, will be at its minimal distance of about 8.2 ly (2.5 pc) from the Sun.[17] The ChView simulation shows that currently its nearest neighbouring star is Lacaille 9352 at about 4.1 ly (1.3 pc) from EZ Aquarii.

  1. ^ a b Cite error: The named reference 2MASS was invoked but never defined (see the help page).
  2. ^ Cite error: The named reference ucac4 was invoked but never defined (see the help page).
  3. ^ a b c Cite error: The named reference RECONS was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference apj142_925 was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference gcvs was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference gcsrv was invoked but never defined (see the help page).
  7. ^ a b Cite error: The named reference apj582_2_1011 was invoked but never defined (see the help page).
  8. ^ a b c d e f g h i Cite error: The named reference Torres2009 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference houdebine2003 was invoked but never defined (see the help page).
  10. ^ a b Cite error: The named reference aaa353_253 was invoked but never defined (see the help page).
  11. ^ Routley, Nick (June 26, 2020). "The 44 Closest Stars and How They Compare to our Sun". Visual Capitalist. Retrieved January 5, 2023.
  12. ^ Cite error: The named reference Gliese1991 was invoked but never defined (see the help page).
  13. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  14. ^ Cite error: The named reference Kunkel was invoked but never defined (see the help page).
  15. ^ Cite error: The named reference Kholopov was invoked but never defined (see the help page).
  16. ^ Cite error: The named reference Popova2016 was invoked but never defined (see the help page).
  17. ^ Cite error: The named reference al36_11_816 was invoked but never defined (see the help page).