Binary star system in the constellation Octans
For other stars with this Bayer designation, see
μ Octantis .
Mu2 Octantis
Observation dataEpoch J2000.0 Equinox J2000.0
Constellation Octans
μ2 Oct A
Right ascension 20h 41m 44.102s [ 1]
Declination −75° 21′ 02.88″[ 1]
Apparent magnitude (V)± 0.007[ 2]
μ2 Oct B
Right ascension 20h 41m 45.5181s [ 3]
Declination −75° 20′ 47.047″[ 3]
Apparent magnitude (V)± 0.011[ 2]
Characteristics
μ2 Oct A
Spectral type
G1V[ 4]
U−B color index
+0.26[ 5]
B−V color index
+0.62[ 5]
μ2 Oct B
Spectral type
G1V[ 6]
Astrometry μ2 Oct A Radial velocity (Rv )± 0.2[ 7] km/s Proper motion (μ) RA: 156.404 mas /yr [ 1] Dec.: −162.214 mas /yr [ 1] Parallax (π)25.0327± 0.0205 mas [ 1] Distance 130.3 ± 0.1 ly pc ) Absolute magnitude (MV )3.28[ 4] μ2 Oct B Radial velocity (Rv )± 0.15[ 3] km/s Proper motion (μ) RA: +163.531 mas /yr [ 3] Dec.: mas /yr [ 3] Parallax (π)25.0379± 0.0167 mas [ 3] Distance 130.27 ± 0.09 ly pc ) Orbit [ 4] Semi-major axis (a)932 AU Details[ 8] μ2 Oct A Mass ± 0.013M ☉ Radius +0.044 R ☉ Luminosity 3.73[ 4] L ☉ Surface gravity (log g )± 0.03[ 4] cgs Temperature ± 52K Metallicity [Fe/H] ± 0.009dex Rotation ± 3[ 4] Rotational velocity (v sin i )1.45[ 4] Age +0.65 Gyr μ2 Oct B Mass +0.017 M ☉ Radius +0.034 R ☉ Temperature ± 52K Metallicity [Fe/H] ± 0.009dex Age +1.03 Gyr Other designations μ2 Oct, CCDM J20417-7521 μ2 Oct A : CD −75°1173HD 196067HIP 102125HR 7864SAO 2578362MASS J20414409-7521029μ2 Oct B : CD −75°1174HD 196068HIP 102128SAO 2578372MASS J20414550-7520471Database references A SIMBAD data Exoplanet Archive data Database references B SIMBAD data
Mu2 Octantis (μ2 Oct) is a binary star system in the constellation Octans , whose primary and secondary stars have apparent magnitudes of +6.481 and 7.153, respectively.[ 2] parallax measurements, it lies 130.3 light-years away.[ 1] [ 3]
The two stars, HD 196067 and HD 196068 (also named μ2 Oct A and μ2 Oct B), are separated at arcseconds astronomical units (AU). The semimajor axis of the stars' orbit is 932 AU.[ 4]
Component A is a G-dwarf star with 1.33 and 1.73 times of the Sun's mass and radius , respectively. Component B also a G-type main-sequence star with a radius 1.19 times larger than the Sun. Their effective temperatures are similar. HD 196068 has a higher metallicity than its companion, the reasons for this are uncertain.[ 8]
Planetary system
From 1998 to 2012, the system was observed using the CORALIE instrument, at the ESO 's La Silla Observatory .[ 4]
In November 2012, a long-period, wide-orbiting planet was deduced by radial velocity around HD 196067. The planet has been pulled to an eccentric orbit by the B star HD 196068. The planet's true mass, as measured by astrometry , is 12.5 M J brown dwarfs .[ 9]
References
^ a b c d e Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties" . Astronomy and Astrophysics . 674 : A1. arXiv :2208.00211 Bibcode :2023A&A...674A...1G . doi :10.1051/0004-6361/202243940 S2CID 244398875 . Gaia DR3 record for this source at VizieR .^ a b c Paunzen, E. (2015-08-01). "A new catalogue of Strömgren-Crawford uvbyβ photometry". Astronomy and Astrophysics . 580 : A23. arXiv :1506.04568 Bibcode :2015A&A...580A..23P . doi :10.1051/0004-6361/201526413 . ISSN 0004-6361 . ^ a b c d e f Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties" . Astronomy and Astrophysics . 674 : A1. arXiv :2208.00211 Bibcode :2023A&A...674A...1G . doi :10.1051/0004-6361/202243940 S2CID 244398875 . Gaia DR3 record for this source at VizieR .^ a b c d e f g h i 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 . S2CID 59467665 . ^ a b Mermilliod, J.-C. (1986). "Compilation of Eggen's UBV data, transformed to UBV (unpublished)" . Catalogue of Eggen's UBV Data . Bibcode :1986EgUBV........0M . ^ Gray, R. O.; et al. (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 . ^ 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 . S2CID 119231169 . ^ a b Flores, M; Yana Galarza, J; Miquelarena, P; Saffe, C; Jaque Arancibia, M; Ibañez Bustos, R V; Jofré, E; Alacoria, J; Gunella, F (2023-12-06). "Elemental abundance differences in the massive planet-hosting wide binary HD 196067−68" . Monthly Notices of the Royal Astronomical Society . 527 (4): 10016– 10024. arXiv :2311.17272 doi :10.1093/mnras/stad3714 ISSN 0035-8711 . ^ a b Li, Yiting; Brandt, Timothy D.; Brandt, G. Mirek; Dupuy, Trent J.; Michalik, Daniel; Jensen-Clem, Rebecca; Zeng, Yunlin; Faherty, Jacqueline ; Mitra, Elena L. (2021). "Precise Masses and Orbits for Nine Radial-velocity Exoplanets" . The Astronomical Journal . 162 (6): 266. arXiv :2109.10422 Bibcode :2021AJ....162..266L . doi :10.3847/1538-3881/ac27ab S2CID 237592581 .
