EZ Aquarii
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Aquarius |
| Right ascension | 22h 38m 33.73s[1] |
| Declination | –15° 17′ 57.3″[1] |
| Apparent magnitude (V) | 12.87 (13.33/13.27/14.03)[2] |
| Characteristics | |
| Spectral type | M5 V[2] |
| U−B color index | +1.54 |
| B−V color index | +1.96[3] |
| R−I color index | +0.64 [citation needed] |
| Astrometry | |
| Radial velocity (Rv) | –59.9[4] km/s |
| Proper motion (μ) | RA: +2314[5] mas/yr Dec.: +2295[5] mas/yr |
| Parallax (π) | 294.3 ± 3.5 mas[6] |
| Distance | 11.1 ± 0.1 ly (3.40 ± 0.04 pc) |
| Absolute magnitude (MV) | 15.64/15.58/16.34[2] |
| Details | |
| Mass | 0.11/0.11/0.10[2] M☉ |
| Temperature | 2,650[7] K |
| Orbit[8] | |
| Primary | EZ Aquarii AC |
| Companion | EZ 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° |
| Other designations | |
| Database references | |
| SIMBAD | data |
EZ Aquarii is a triple star system approximately 11.3 ly (3.5 pc) from the Sun in the constellation Aquarius. It is also known as Luyten 789-6 and Gliese 866 and all three components are M-type red dwarfs. The pair EZ Aquarii AC form a spectroscopic binary with a 3.8-day orbit and a 0.03 AU separation. This pair share an orbit with EZ Aquarii B that has an 823-day period.[9] The A and B components of Luyten 789-6 together emit X-rays.[10]
The configuration of the inner binary pair may permit a circumbinary planet to orbit near their habitable zone.[11] 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.[12] The ChView simulation shows that currently its nearest neighbouring star is Lacaille 9352 at about 4.1 ly (1.3 pc) from EZ Aquarii.
See also
References
- ^ a b Cutri, R. M.; et al. (June 2003). 2MASS All Sky Catalog of point sources. NASA. Bibcode:2003tmc..book.....C.
- ^ a b c d "The One Hundred Nearest Star Systems". RECONS. Georgia State University. Retrieved 2010-06-30.
- ^ Eggen, O. J.; Greenstein, J. L. (October 1965). "Observations of proper-motion stars. II". Astrophysical Journal. 142: 925. Bibcode:1965ApJ...142..925E. doi:10.1086/148362.
- ^ Wilson, Ralph Elmer (1953). General Catalogue of Stellar Radial Velocities. Washington: Carnegie Institution of Washington. Bibcode:1953GCRV..C......0W.
- ^ a b Salim, Samir; Gould, Andrew (January 2003). "Improved Astrometry and Photometry for the Luyten Catalog. II. Faint Stars and the Revised Catalog". The Astrophysical Journal. 582 (2): 1011–1031. arXiv:astro-ph/0206318. Bibcode:2003ApJ...582.1011S. doi:10.1086/344822.
- ^ Gliese, W.; Jahreiß, H. (1991). "Gl 866". Preliminary Version of the Third Catalogue of Nearby Stars. Retrieved 2014-10-20.
- ^ Casagrande, Luca; Flynn, Chris; Bessell, Michael (September 2008). "M dwarfs: effective temperatures, radii and metallicities". Monthly Notices of the Royal Astronomical Society. 389 (2): 585–607. arXiv:0806.2471. Bibcode:2008MNRAS.389..585C. doi:10.1111/j.1365-2966.2008.13573.x.
{{cite journal}}: CS1 maint: unflagged free DOI (link) - ^ Woitas, J.; Leinert, Ch.; Jahreiß, H.; Henry, T.; Franz, O. G.; Wasserman, L. H.; Leinert; Jahreiß; Henry; Franz; Wasserman (January 2000). "The nearby M-dwarf system Gliese 866 revisited". Astronomy and Astrophysics. 353: 253–256. arXiv:astro-ph/9910411. Bibcode:2000A&A...353..253W.
{{cite journal}}: CS1 maint: multiple names: authors list (link) - ^ Delfosse, X.; et al. (October 1999), "Accurate masses of very low mass stars. II. The very low mass triple system GL 866", Astronomy and Astrophysics, 350: L39–L42, arXiv:astro-ph/9909409, Bibcode:1999A&A...350L..39D
- ^ Schmitt, J.H.M.M.; Golub, L.; Harnden, F.R. Jr.; Maxson, C.W.; Rosner, R.; Vaiana, G.S. (March 1985). "An Einstein Observatory X-ray survey of main-sequence stars with shallow convection zones". Astrophysical Journal. 290 (Part 1): 307–320. Bibcode:1985ApJ...290..307S. doi:10.1086/162986.
- ^ Popova, E. A.; Shevchenko, I. I. (April 2016), "On possible circumbinary configurations of the planetary systems of α Centauri and EZ Aquarii", Astronomy Letters, 42 (4): 260−267, Bibcode:2016AstL...42..260P, doi:10.1134/S106377371604006X.
- ^ Bobylev, V. V. (November 2010), "Stars outside the Hipparcos list closely encountering the Solar system", Astronomy Letters, 36 (11): 816–822, arXiv:1009.4856, Bibcode:2010AstL...36..816B, doi:10.1134/S1063773710110071
External links
- Image EZ Aquarii
- Solstation provides an orbital animation as well as a visualization of the habitable zone around EZ Aquarii B.
