HD 165189
HD 165189 and HD 165190 are components of a visual binary star[5] system located 145[1] light years away in the southern constellation of Corona Australis. It is visible to the naked eye with the primary having an apparent visual magnitude of 4.929±0.025. The system is a member of the Beta Pictoris Moving Group.[3]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Corona Australis |
| Right ascension | 18h 06m 49.89282s[1] |
| Declination | −43° 25′ 30.8022″[1] |
| Apparent magnitude (V) | 4.92[2] |
| Characteristics | |
| Spectral type | A6 V + A7 V[3] |
| B−V color index | 0.255±0.017[2] |
| Astrometry | |
| Radial velocity (Rv) | −7.80±0.40[2] km/s |
| Proper motion (μ) | RA: +10.990[1] mas/yr Dec.: −105.742[1] mas/yr |
| Parallax (π) | 22.4417 ± 0.1608[1] mas |
| Distance | 145 ± 1 ly (44.6 ± 0.3 pc) |
| Absolute magnitude (MV) | 1.81[2] |
| Orbit[4] | |
| Period (P) | 450.0 yr |
| Semi-major axis (a) | 2.04″ |
| Eccentricity (e) | 0.650 |
| Inclination (i) | 123.1° |
| Longitude of the node (Ω) | 85.8° |
| Periastron epoch (T) | 1854.7 |
| Argument of periastron (ω) (secondary) | 282.7° |
| Details | |
| HD 165189 | |
| Mass | 1.59[5] M☉ |
| Luminosity | 36.4+6.4 −5.2[6] L☉ |
| Temperature | 7,745+53 −46[6] K |
| Rotational velocity (v sin i) | 104[7] km/s |
| HD 165190 | |
| Mass | 1.58[5] M☉ |
| Other designations | |
| HD 165189: HR 6749 | |
| HD 165190: HR 6750 | |
| Database references | |
| SIMBAD | data |
The pair orbit each other with a period of 450 years and a large eccentricity of 0.650.[4] They have a projected separation of 70.1 AU.[5] Both components are A-type main-sequence stars; the primary has a stellar classification of A6 V while the secondary is A7 V.[3] They have similar masses of 1.59 and 1.58 times the mass of the Sun, respectively.[5]
References
- Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051.
- Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv:1108.4971, Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015.
- Bell, Cameron P. M.; et al. (November 2015), "A self-consistent, absolute isochronal age scale for young moving groups in the solar neighbourhood", Monthly Notices of the Royal Astronomical Society, 454 (1): 593–614, arXiv:1508.05955, Bibcode:2015MNRAS.454..593B, doi:10.1093/mnras/stv1981.
- Alzner, A.; Argyle, R. (June 2001), "New orbits for WDS 05248-5219, WDS 18068-4325", IAU Commission 26. (Double Stars) Information Circular: 1–2, Bibcode:2001IAUDS.144R...1A.
- Tokovinin, A.; Kiyaeva, O. (February 2016), "Eccentricity distribution of wide binaries", Monthly Notices of the Royal Astronomical Society, 456 (2): 2070–2079, arXiv:1512.00278, Bibcode:2016MNRAS.456.2070T, doi:10.1093/mnras/stv2825.
- Zorec, J.; et al. (2012), "Rotational velocities of A-type stars. IV. Evolution of rotational velocities", Astronomy and Astrophysics, 537: A120, arXiv:1201.2052, Bibcode:2012A&A...537A.120Z, doi:10.1051/0004-6361/201117691.
- Royer, F.; Gerbaldi, M.; Faraggiana, R.; Gómez, A. E. (January 2002), "Rotational velocities of A-type stars. I. Measurement of v sin i in the southern hemisphere", Astronomy and Astrophysics, 381: 105–121, arXiv:astro-ph/0110490, Bibcode:2002A&A...381..105R, doi:10.1051/0004-6361:20011422.
- "CD-43 12272". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-01-07.
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