Mu2 Octantis

{{Short description|Binary star system in the constellation Octans}}

{{other stars by Bayer designation|Mu Octantis{{!}}μ Octantis}}

{{Starbox begin

| name = Mu² Octantis

}}

{{Starbox observe 2s

| epoch = J2000.0

| constell = Octans

| component1 = μ² Oct A

| ra1 = {{RA|20|41|44.102}}

| dec1 = {{DEC|-75|21|02.88}}

| appmag_v1 = {{Val|+6.481|0.007}}

| component2 = μ² Oct B

| ra2 = {{RA|20|41|45.5181}}

| dec2 = {{DEC|-75|20|47.047}}

| appmag_v2 = {{val|+7.153|0.011}}

}}

{{Starbox character

| component1 = μ² Oct A

| class = G1V

| b-v = +0.62

| u-b = +0.26

| component2 = μ² Oct B

| class2 = G1V

}}

{{Starbox astrometry

| component1 =μ² Oct A

| radial_v = {{val|-10.90|0.2}}

| prop_mo_ra = 156.404

| prop_mo_dec = −162.214

| pm_footnote =

| parallax = 25.0327

| p_error = 0.0205

| parallax_footnote =

| absmag_v = 3.28

| component2 =μ² Oct B

| radial_v2 = {{Val|-10.94|0.15}}

| prop_mo_ra2 = +163.531

| prop_mo_dec2 = {{Val|-171.346}}

| pm_footnote2 =

| parallax2 = 25.0379

| p_error2 = 0.0167

| parallax_footnote2 =

}}

{{Starbox orbit

| reference =

| axis_unitless = 932 AU

}}

{{Starbox detail

| source =

| component1 =μ² Oct A

| mass = {{val|1.330|0.013}}

| radius = {{val|1.730|0.044|0.039}}

| luminosity = 3.73

| gravity = {{val|4.24|0.03}}

| temperature = {{val|6059|52|fmt=commas}}

| metal_fe = {{val|+0.216|0.009}}

| age_gyr = {{val|3.50|0.65|0.27}}

| rotational_velocity = 1.45

| rotation = {{val|26|3}} days

| component2 = μ² Oct B

| mass2 = {{val|1.190|0.017|0.018}}

| radius2 = {{val|1.190|0.034|0.010}}

| temeprature2 = {{val|6020|52|fmt=commas}}

| age_gyr2 = {{val|2.10|1.03|0.34}}

| metal_fe2 = {{val|+0.267|0.009}}

}}

{{Starbox catalog

| names = μ² Oct, CCDM J20417-7521

| component1 = μ² Oct A

| names1 = {{odlist|HIP=102125|CD=-75°1173|HD=196067|SAO=257836|HR=7864|2MASS=J20414409-7521029}}

| component2 = μ² Oct B

| names2 = {{odlist|HD=196068|HIP=102128|CD=-75°1174|SAO=257837|2MASS=J20414550-7520471}}

}}

{{Starbox reference

| component = A

| Simbad = CCDM+J20417-7521A

| NSTED = HD 196067

| EPE = HD+196067

}}

{{Starbox reference

| component = B

| Simbad = HD+196068

}}

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. Based on parallax measurements, it lies 130.3 light-years away.

The two stars, HD 196067 and HD 196068 (also named μ² Oct A and μ² Oct B), are separated at {{val|17|ul=arcseconds}} in the sky, corresponding to 740 astronomical units (AU). The semimajor axis of the stars' orbit is 932 AU.

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.

Planetary system

From 1998 to 2012, the system was observed using the CORALIE instrument, at the ESO's La Silla Observatory.

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 {{Jupiter mass|12.5|link=y}}, placing it right on the boundary between planets and brown dwarfs.

{{OrbitboxPlanet begin|name=μ² Oct A

| table_ref = {{cite journal | doi=10.3847/1538-3881/ac27ab | title=Precise Masses and Orbits for Nine Radial-velocity Exoplanets | year=2021 | last1=Li | first1=Yiting | last2=Brandt | first2=Timothy D. | last3=Brandt | first3=G. Mirek | last4=Dupuy | first4=Trent J. | last5=Michalik | first5=Daniel | last6=Jensen-Clem | first6=Rebecca | last7=Zeng | first7=Yunlin | last8=Faherty | first8=Jacqueline|author8-link=Jackie Faherty | last9=Mitra | first9=Elena L. | journal=The Astronomical Journal | volume=162 | issue=6 | page=266 | arxiv=2109.10422 | bibcode=2021AJ....162..266L | s2cid=237592581 | doi-access=free }}

| period_unit = year

}}

{{OrbitboxPlanet

| exoplanet = b

| semimajor = {{val|5.10|0.22|0.17}}

| eccentricity = {{val|0.70|0.14|0.12}}

| period = {{val|9.88|+0.63|−0.43}}

| mass = {{val|12.5|+2.5|-1.8}}

| inclination = {{val|41.2|28|9.1}}

}}

References

{{Reflist|refs=

{{cite journal | title=The CORALIE survey for southern extrasolar planets XVII. New and updated long period and massive planets | last1=Marmier | first1=M. | last2=Ségransan | first2=D. | last3=Udry | first3=S. | last4=Mayor | first4=M. | last5=Pepe | first5=F. | last6=Queloz | first6=D. | last7=Lovis | first7=C. | last8=Naef | first8=D. | last9=Santos | first9=N. C. | last10=Alonso | first10=R. | last11=Alves | first11=S. | last12=Berthet | first12=S. | last13=Chazelas | first13=B. | last14=Demory | first14=B.-O. | last15=Dumusque | first15=X. | last16=Eggenberger | first16=A. | last17=Figueira | first17=P. | last18=Gillon | first18=M. | last19=Hagelberg | first19=J. | last20=Lendl | first20=M. | last21=Mardling | first21=R. A. | last22=Mégevand | first22=D. | last23=Neveu | first23=M. | last24=Sahlmann | first24=J. | last25=Sosnowska | first25=D. | last26=Tewes | first26=M. | last27=Triaud | first27=A. H. M. J. | display-authors=1 | journal=Astronomy and Astrophysics | volume=551 | at=A90 | year=2013 | arxiv=1211.6444 | bibcode=2013A&A...551A..90M | doi=10.1051/0004-6361/201219639 | s2cid=59467665 }}

{{Cite journal |last=Paunzen |first=E. |date=2015-08-01 |title=A new catalogue of Strömgren-Crawford uvbyβ photometry |bibcode=2015A&A...580A..23P |journal=Astronomy and Astrophysics |volume=580 |pages=A23 |doi=10.1051/0004-6361/201526413 |issn=0004-6361|arxiv=1506.04568 }}

{{cite journal|title=Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system|author=Gontcharov, G. A.|date=2006|journal=Astronomy Letters|volume=32|issue=11|pages=759–771|bibcode=2006AstL...32..759G|doi=10.1134/S1063773706110065|arxiv=1606.08053|s2cid=119231169}}

{{cite journal|author1=Mermilliod, J.-C.|title=Compilation of Eggen's UBV data, transformed to UBV (unpublished)|journal=Catalogue of Eggen's UBV Data|url=http://cdsads.u-strasbg.fr/cgi-bin/nph-bib_query?1986EgUBV........0M&db_key=AST&nosetcookie=1|date=1986|bibcode= 1986EgUBV........0M}}

{{Cite journal |last1=Flores |first1=M |last2=Yana Galarza |first2=J |last3=Miquelarena |first3=P |last4=Saffe |first4=C |last5=Jaque Arancibia |first5=M |last6=Ibañez Bustos |first6=R V |last7=Jofré |first7=E |last8=Alacoria |first8=J |last9=Gunella |first9=F |date=2023-12-06 |title=Elemental abundance differences in the massive planet-hosting wide binary HD 196067−68 |journal=Monthly Notices of the Royal Astronomical Society |volume=527 |issue=4 |pages=10016–10024 |doi=10.1093/mnras/stad3714 |doi-access=free |arxiv=2311.17272 |issn=0035-8711}}

{{cite journal|bibcode=2006AJ....132..161G|title=Contributions to the Nearby Stars (NStars) Project: Spectroscopy of Stars Earlier than M0 within 40 pc—The Southern Sample|author=Gray, R. O.|year=2006|journal=The Astronomical Journal|volume=132|issue=1|pages=161–170|doi=10.1086/504637|arxiv = astro-ph/0603770 |s2cid=119476992|display-authors=etal}}

}}

Category:Planetary systems with one confirmed planet

Category:Binary stars

Category:Octans

Category:Durchmusterung objects

Category:G-type main-sequence stars

J20414409-7521029