Zeta Trianguli Australis (ζ TrA) is a spectroscopic binary in the constellation Triangulum Australe. It is approximately 39.5 light years from Earth.
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Triangulum Australe |
| Right ascension | 16h 28m 28.14362s[1] |
| Declination | −70° 05′ 03.8419″[1] |
| Apparent magnitude (V) | 4.90[2] |
| Characteristics | |
| Spectral type | F9 V[3] |
| U−B color index | +0.02[2] |
| B−V color index | +0.55[4] |
| Astrometry | |
| Radial velocity (Rv) | +8.3[5] km/s |
| Proper motion (μ) | RA: 199.97[1] mas/yr Dec.: 110.97[1] mas/yr |
| Parallax (π) | 82.53 ± 0.52 mas[1] |
| Distance | 39.5 ± 0.2 ly (12.12 ± 0.08 pc) |
| Absolute magnitude (MV) | 4.49[6] |
| Orbit[7] | |
| Period (P) | 12.97662 ± 0.00017 d |
| Eccentricity (e) | 0.01442 ± 0.00021 |
| Periastron epoch (T) | JD 2452752.31955 |
| Argument of periastron (ω) (secondary) | 252.98° ± 0.80° |
| Semi-amplitude (K1) (primary) | 7.4988 ± 0.0016 km/s |
| Details | |
| ζ TrA A | |
| Mass | 1.12[8] M☉ |
| Metallicity [Fe/H] | –0.18[4] dex |
| Rotation | 13 days[4] |
| Rotational velocity (v sin i) | 3.23[9] km/s |
| Age | 600–900[10] Myr |
| ζ TrA B | |
| Mass | 0.40[8] M☉ |
| Other designations | |
| Database references | |
| SIMBAD | data |
| ARICNS | data |
The binary's composite spectral class is F9V and its combined apparent magnitude is +4.90. The pair orbit each other once every 13 days, and the orbital eccentricity is a low 0.014, making it nearly circular.[7]
Somewhat surprisingly for a star located at 70° S, it is a candidate swarm member of the Ursa Major moving group.[11] However, there is some evidence to the contrary.[4]
References edit
- ^ a b c d e van Leeuwen, Floor (November 2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752v1, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357, S2CID 18759600. Note: see VizieR catalogue I/311.
- ^ a b Mermilliod, J.-C. (1986), "Compilation of Eggen's UBV data, transformed to UBV (unpublished)", Catalogue of Eggen's UBV Data. SIMBAD, Bibcode:1986EgUBV........0M.
- ^ Gray, R. O.; et al. (July 2006), "Contributions to the Nearby Stars (NStars) Project: spectroscopy of stars earlier than M0 within 40 pc-The Southern Sample", The Astronomical Journal, 132 (1): 161–170, arXiv:astro-ph/0603770, Bibcode:2006AJ....132..161G, doi:10.1086/504637, S2CID 119476992.
- ^ a b c d Maldonado, J.; et al. (October 2010), "A spectroscopy study of nearby late-type stars, possible members of stellar kinematic groups", Astronomy and Astrophysics, 521: A12, arXiv:1007.1132, Bibcode:2010A&A...521A..12M, doi:10.1051/0004-6361/201014948, S2CID 119209183.
- ^ Gontcharov, G. A. (November 2006), "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system", Astronomy Letters, 32 (11): 759–771, arXiv:1606.08053, Bibcode:2006AstL...32..759G, doi:10.1134/S1063773706110065, S2CID 119231169.
- ^ Holmberg, J.; et al. (July 2009), "The Geneva-Copenhagen survey of the solar neighbourhood. III. Improved distances, ages, and kinematics", Astronomy and Astrophysics, 501 (3): 941–947, arXiv:0811.3982, Bibcode:2009A&A...501..941H, doi:10.1051/0004-6361/200811191, S2CID 118577511.
- ^ a b Skuljan, Jovan (2004), "Accurate orbital parameters for the bright southern spectroscopic binary ζ Trianguli Australis – an interesting case of a near-circular orbit", Monthly Notices of the Royal Astronomical Society, 352 (3): 975, Bibcode:2004MNRAS.352..975S, doi:10.1111/j.1365-2966.2004.07988.x.
- ^ a b Tokovinin, Andrei (April 2014), "From Binaries to Multiples. II. Hierarchical Multiplicity of F and G Dwarfs", The Astronomical Journal, 147 (4): 14, arXiv:1401.6827, Bibcode:2014AJ....147...87T, doi:10.1088/0004-6256/147/4/87, S2CID 56066740, 87.
- ^ Martínez-Arnáiz, R.; et al. (September 2010), "Chromospheric activity and rotation of FGK stars in the solar vicinity. An estimation of the radial velocity jitter", Astronomy and Astrophysics, 520: A79, arXiv:1002.4391, Bibcode:2010A&A...520A..79M, doi:10.1051/0004-6361/200913725, S2CID 43455849.
- ^ Mamajek, Eric E.; Hillenbrand, Lynne A. (November 2008), "Improved Age Estimation for Solar-Type Dwarfs Using Activity-Rotation Diagnostics", The Astrophysical Journal, 687 (2): 1264–1293, arXiv:0807.1686, Bibcode:2008ApJ...687.1264M, doi:10.1086/591785, S2CID 27151456.
- ^ Croswell, Ken (2005). "Descendants of the Dipper". Astronomy. 33 (3): 40–45. Bibcode:2005Ast....33c..40C. ISSN 0091-6358.
 | This binary or multiple star system-related article is a stub. You can help Wikipedia by expanding it. |