Zeta Trianguli Australis
| 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[1] mas |
| Distance | 39.5 ± 0.2 ly (12.12 ± 0.08 pc) |
| Details | |
| ζ TrA A | |
| Mass | 1.12[6] M☉ |
| Metallicity [Fe/H] | –0.18[4] dex |
| Rotation | 13 days[4] |
| Rotational velocity (v sin i) | 3.23[7] km/s |
| Age | 600–900[8] Myr |
| ζ TrA B | |
| Mass | 0.40[6] M☉ |
| Orbit[9] | |
| 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 |
| Other designations | |
Zeta Trianguli Australis (ζ TrA) is a spectroscopic binary in the constellation Triangulum Australe. It is approximately 39.5 light years from Earth.
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.[9]
Somewhat surprisingly for a star located at 70° S, it is a candidate swarm member of the Ursa Major moving group.[10] However, there is some evidence to the contrary.[4]
References
- 1 2 3 4 5 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. Note: see VizieR catalogue I/311. - 1 2 Mermilliod, J.-C. (1986), "Compilation of Eggen's UBV data, transformed to UBV (unpublished)", Catalogue of Eggen's UBV data.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.
- 1 2 3 4 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.
- ↑ 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, Bibcode:2006AstL...32..759G, doi:10.1134/S1063773706110065.
- 1 2 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, 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.
- ↑ 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.
- 1 2 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: 975, Bibcode:2004MNRAS.352..975S, doi:10.1111/j.1365-2966.2004.07988.x.
- ↑ Croswell, Ken (2005). "Descendants of the Dipper". Astronomy. 33 (3): 40–45. ISSN 0091-6358.
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