HD 156279

{{Short description|Star in the constellation Draco}} {{Starbox begin}} {{Starbox observe | constell = [[Draco (constellation)|Draco]]<ref name=Anderson_Francis_2012/> | epoch = J2000 | ra = {{RA|17|12|23.204816}}<ref name=GaiaDR3/> | dec = {{DEC|+63|21|07.531205}}<ref name=GaiaDR3/> | appmag_v = 8.167{{±|0.013}}<ref name=Fontanive2019/> }} {{Starbox character | type = main-sequence<ref name=Diaz2011/> | class = K0<ref name=Fontanive2019/> or G6<ref name=Diaz2011/> | b-v = 0.801{{±|0.014}}<ref name=Anderson_Francis_2012/> | appmag_1_passband = R | appmag_1 = 7.60<ref name=Anderson_Francis_2012/> | appmag_2_passband = G | appmag_2 = 7.8657<ref name=GaiaDR3/> | appmag_3_passband = J | appmag_3 = 6.677{{±|0.018}}<ref name=Anderson_Francis_2012/> | variable = }} {{Starbox astrometry | radial_v = {{val|−20.144|0.161}}<ref name=Carrera_et_al_2022/> | prop_mo_ra = {{val|−1.879|0.024}} | prop_mo_dec = {{val|160.429|0.027}} | pm_footnote = <ref name=GaiaDR3/> | parallax = 27.6756 | p_error = 0.0200 | parallax_footnote = <ref name=GaiaDR3/> | absmag_v = 5.25<ref name=Anderson_Francis_2012/> }} {{Starbox detail | mass = {{Val|0.999|0.046|0.045}}<ref name=An2025/> | temperature = 5,449{{±|31}}<ref name=Bonfanti_et_al_2016/> | luminosity = 0.70{{±|0.01}}<ref name=Bonfanti_et_al_2016/> | radius = 0.94{{±|0.02}}<ref name=Bonfanti_et_al_2016/> | gravity = 4.45{{±|0.03}}<ref name=Bonfanti_et_al_2016/> | age_gyr = 7.4{{±|2.2}}<ref name=Bonfanti_et_al_2016/> | metal_fe = 0.14{{±|0.01}}<ref name=Fontanive2019/> | rotational_velocity = 2.51{{±|1}}<ref name=Diaz2011/> }} {{Starbox catalogue | names = {{odlist | HD=156279 | HIP=84171 | BD=+63 1335 | SAO=17390 | NLTT=44404 | PPM=20265 | TYC=4202-656-1 | 2MASS=J17122319+6321074 | Gaia DR2=1631084478574318976 }}<ref name=SIMBAD/> }} {{Starbox reference | Simbad = HD+156279 }} {{Starbox end }}

'''HD 156279''' is a [[star]] with a pair of orbiting [[exoplanets]]<ref name=Bryan2016/> located in the northern [[constellation]] of [[Draco (constellation)|Draco]].<ref name=Anderson_Francis_2012/> It has various alternate designations, including HIP 84171 and BD+63 1335. [[Stellar parallax|Parallax]] measurements yield a distance of 118 [[light year]]s from the Sun,<ref name=GaiaDR3/> but it is drifting closer with a [[radial velocity]] of −20 km/s.<ref name=Carrera_et_al_2022/> Despite an [[absolute magnitude]] of 5.25,<ref name=Anderson_Francis_2012/> at that distance the star is too faint to be visible to the naked eye with an [[apparent visual magnitude]] of 8.17.<ref name=Fontanive2019/> It is presumed to be a single star, as in 2019 all imaging surveys have failed to find any stellar companions.<ref name=Fontanive2019/>

The [[stellar spectrum|spectrum]] of HD 156279 has a [[stellar classification]] of G6<ref name=Diaz2011/> or K0,<ref name=Fontanive2019/> depending on the study. Hence it presents as an ordinary [[main sequence]] star<ref name=Diaz2011/> of the [[late type star|late]] [[G-type main-sequence star|G-type]] or early [[K-type main-sequence star|K-type]]. The star has 93% of the mass of the Sun and 94% of the Sun's radius. HD 156279 is roughly seven<ref name=Bonfanti_et_al_2016/> billion years old and is spinning with a [[projected rotational velocity]] of 2.5 km/s.<ref name=Diaz2011/> Based on the abundance of iron, this star is slightly enriched in heavy elements, having 140% of the solar abundance.<ref name=Fontanive2019/> It is radiating 70%<ref name=Bonfanti_et_al_2016/> of the luminosity of the Sun from its [[photosphere]] at an [[effective temperature]] of 5,449 K.<ref name=Bonfanti_et_al_2016/>

==Planetary system== Orbiting HD 156279 are two [[superjovian]] planets, the inner HD 156279 b (discovered in 2011)<ref name=Diaz2011/> and outer HD 156279 c (discovered in 2016).<ref name=Bryan2016/> In 2022, the inclination and true mass of HD 156279 c were measured for the first time, using the [[astrometry]] technique.<ref name="Feng2022"/>

{{OrbitboxPlanet begin | table_ref = <ref name=An2025/> | period_unit = year }} {{OrbitboxPlanet | exoplanet = b | mass = {{val|9.82|0.29|p=≥ }} | radius = | semimajor = {{val|0.5126|0.0077|0.0078}} | period = {{val|0.365235|(10)}} | eccentricity = {{val|0.6479|0.00070|0.00077}} | inclination = }} {{OrbitboxPlanet | exoplanet = c | mass = {{val|10.53|0.65|0.59}} | radius = | semimajor = {{val|5.570|0.086|0.084}} | period = {{val|13.093|0.081}} | eccentricity = {{val|0.2602|0.0047|0.0048}} | inclination = {{val|110.9|6.9|9.4}} }} {{Orbitbox end}}

==References== {{Reflist|refs=

<ref name=SIMBAD>{{cite simbad | title=HD 156279 | access-date = 13 October 2020}}</ref>

<ref name=Anderson_Francis_2012>{{citation | postscript=. | last1=Anderson | first1=E. | last2=Francis | first2=Ch. | title=XHIP: An extended hipparcos compilation | journal=Astronomy Letters | volume=38 | issue=5 | pages=331 | year=2012 | bibcode=2012AstL...38..331A | arxiv=1108.4971 | doi=10.1134/S1063773712050015 | s2cid=119257644 }}</ref>

<ref name=Carrera_et_al_2022>{{citation | postscript=. | title=OCCASO. IV. Radial velocities and open cluster kinematics | display-authors=1 | last1=Carrera | first1=R. | last2=Casamiquela | first2=L. | last3=Carbajo-Hijarrubia | first3=J. | last4=Balaguer-Núñez | first4=L. | last5=Jordi | first5=C. | last6=Romero-Gómez | first6=M. | last7=Blanco-Cuaresma | first7=S. | last8=Cantat-Gaudin | first8=T. | last9=Lillo-Box | first9=J. | last10=Masana | first10=E. | last11=Pancino | first11=E. | journal=Astronomy & Astrophysics | volume=658 | id=A14 | date=February 2022 | doi=10.1051/0004-6361/202141832 | arxiv=2110.02110 | bibcode=2022A&A...658A..14C }}</ref>

<ref name=Bonfanti_et_al_2016>{{citation | postscript=. | title=Age consistency between exoplanet hosts and field stars | display-authors=1 | last1=Bonfanti | first1=A. | last2=Ortolani | first2=S. | last3=Nascimbeni | first3=V. | journal=Astronomy & Astrophysics | year=2016 | volume=585 | id=A5 | pages=14 | arxiv=1511.01744 | bibcode=2016A&A...585A...5B | doi=10.1051/0004-6361/201527297 | s2cid=53971692 }}</ref>

<ref name=Bryan2016>{{citation | postscript=. | title=Statistics of long period gas giant planets in known planetary systems | last1=Bryan | first1=Marta L. | last2=Knutson | first2=Heather A. | last3=Howard | first3=Andrew W. | last4=Ngo | first4=Henry | last5=Batygin | first5=Konstantin | last6=Crepp | first6=Justin R. | last7=Fulton | first7=B. J. | last8=Hinkley | first8=Sasha | last9=Isaacson | first9=Howard | last10=Johnson | first10=John A. | last11=Marcy | first11=Geoffry W. | last12=Wright | first12=Jason T. | display-authors=1 | journal=The Astrophysical Journal | volume=821 | issue=2 | page=89 | year=2016 | doi=10.3847/0004-637X/821/2/89 | doi-access=free | arxiv=1601.07595 | bibcode=2016ApJ...821...89B | s2cid=19709252 }}</ref>

<ref name=Fontanive2019>{{citation | postscript=. | title=A high binary fraction for the most massive close-in giant planets and brown dwarf desert members | display-authors=1 | last1=Biller | first1=B. | last2=Mužić | first2=K. | last3=Lopez | first3=E. | last4=Bonavita | first4=M. | last5=Rice | first5=K. | last6=Fontanive | first6=C. | last7=Biller | first7=B. | journal=Monthly Notices of the Royal Astronomical Society | volume=485 | issue=4 | pages=4967–4996 | year=2019 | doi=10.1093/mnras/stz671 | doi-access=free | arxiv=1903.02332 | bibcode=2019MNRAS.485.4967F | s2cid=84180618}}</ref>

<ref name="Feng2022">{{citation | postscript=. | title=3D Selection of 167 Substellar Companions to Nearby Stars | last1=Feng | first1=Fabo | last2=Butler | first2=R. Paul | display-authors=etal | journal=[[The Astrophysical Journal Supplement Series]] | volume=262 | issue=21 | page=21 | date=August 2022 | doi=10.3847/1538-4365/ac7e57 | arxiv=2208.12720 | doi-access=free | bibcode=2022ApJS..262...21F | s2cid=251864022 }}</ref>

<ref name=Diaz2011>{{citation | postscript=. | title=The SOPHIE search for northern extrasolar planets IV. Massive companions in the planet-brown dwarf boundary | display-authors=1 | last1=Díaz | first1=Rodrigo F. | last2=Santerne | first2=Alexandre | last3=Sahlmann | first3=Johannes | last4=Hébrard | first4=Guillaume | last5=Eggenberger | first5=Anne | last6=Santos | first6=Nuno C. | last7=Moutou | first7=Claire | last8=Arnold | first8=Luc | last9=Boisse | first9=Isabelle | last10=Bonfils | first10=Xavier | last11=Bouchy | first11=François | last12=Delfosse | first12=Xavier | last13=Desort | first13=Morgan | last14=Ehrenreich | first14=David | last15=Forveille | first15=Thierry | last16=Lagrange | first16=Anne-Marie | last17=Lovis | first17=Christophe | last18=Pepe | first18=Francesco | last19=Perrier | first19=Christian | last20=Queloz | first20=Didier | last21=Ségransan | first21=Damien | last22=Udry | first22=Stéphane | last23=Vidal-Madjar | first23=Alfred | journal=Astronomy & Astrophysics | volume=A113 | page=538 | year=2012 | doi=10.1051/0004-6361/201117935 | arxiv=1111.1168 | bibcode=2012A&A...538A.113D |s2cid=55322205 }}</ref>

<ref name=An2025>{{ciation |last=An |first=Qier |last2=Brandt |first2=Timothy D. |last3=Brandt |first3=G. Mirek |last4=Venner |first4=Alexander |title=Orbits and Masses for 156 Companions from Combined Astrometry and Radial Velocities, and A Validation of Gaia Non-Single Star Solutions |date=2025-08-11 |journal=[[The Astrophysical Journal Supplement Series]] |arxiv=2508.08374}}.</ref>

}}

[[Category:G-type main-sequence stars]] [[Category:K-type main-sequence stars]] [[Category:Planetary systems with two confirmed planets]]  [[Category:Draco (constellation)]] [[Category:Durchmusterung objects]] [[Category:Henry Draper Catalogue objects|156279]] [[Category:Hipparcos objects|084171]]