Mu2 Octantis
Mu2 Octantis (μ2 Oct) is a binary star system of two G-type main-sequence stars. It shares the designation μ with μ1 Octantis, from which it is separated by 50 arcminutes.
Observation data Epoch J2000.0 Equinox J2000.0 | |
---|---|
Constellation | Octans |
Right ascension | 20h 41m 44.088s[1] |
Declination | –75° 21′ 02.87″[1] |
Apparent magnitude (V) | +6.51[2] |
Characteristics | |
Spectral type | G1V[3] |
U−B color index | +0.26[4] |
B−V color index | +0.62[4] |
Astrometry | |
Radial velocity (Rv) | -10.90 ± 0.2[5] km/s |
Proper motion (μ) | RA: 149.53 ± 2.28[1] mas/yr Dec.: –158.45 ± 2.47[1] mas/yr |
Parallax (π) | 22.59 ± 2.62[1] mas |
Distance | approx. 140 ly (approx. 44 pc) |
Absolute magnitude (MV) | 3.28[3] |
Details[3] | |
Mass | 1.29 ± 0.08 M☉ |
Radius | 1.73 ± 0.21 R☉ |
Luminosity | 3.73 L☉ |
Surface gravity (log g) | 4.24 ± 0.03 cgs |
Temperature | 6017 ± 46 K |
Metallicity [Fe/H] | 0.18 ± 0.04 dex |
Rotation | 26 ± 3 |
Rotational velocity (v sin i) | 1.45 km/s |
Age | 3.3 ± 0.6 Gyr |
Other designations | |
Database references | |
SIMBAD | data |
Exoplanet Archive | data |
Extrasolar Planets Encyclopaedia | data |
The primary star (A) is HD 196067, whose data is in the starbox. The secondary star (B) is HD 196068 (HIP 102128, LTT 8160),[6] another G-type main-sequence star with an apparent magnitude of 7.18.[3] Its effective temperature 5997 K, and its mass is 1.18 ± 0.07 M☉.[3] The two are gravitationally bound and separated at 17 arcseconds in our sky, corresponding to 740 astronomical units (AU). The binary semimajor axis is 932 AU.[3]
Planetary system
From 1998 to 2012, the system was observed using the CORALIE instrument, at the ESO's La Silla Observatory.[3]
In 2012, a long-period, wide-orbiting planet was deduced by radial velocity around HD 196067. This was published in November. The planet has been pulled to an eccentric orbit by the B star HD 196068.
Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
---|---|---|---|---|---|---|
b | >6.9+3.9 −1.1 MJ |
5.02 ± 0.19 | 3638+232 −185 |
0.66+0.18 −0.09 |
— | — |
References
- van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653–664. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357.Vizier catalog entry
- "* mu.02 Oct". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 5 August 2017.
- Marmier, M.; et al. (2013). "The CORALIE survey for southern extrasolar planets XVII. New and updated long period and massive planets". Astronomy and Astrophysics. 551. A90. arXiv:1211.6444. Bibcode:2013A&A...551A..90M. doi:10.1051/0004-6361/201219639.
- Mermilliod, J.-C. (1986). "Compilation of Eggen's UBV data, transformed to UBV (unpublished)". Bibcode:1986EgUBV........0M. Cite journal requires
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(help) - Gontcharov, G. A. (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.
- "HD 196068". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 5 August 2017.
- "Planet HD 196067 b". The Extrasolar Planets Encyclopaedia. Retrieved 5 August 2017.