{{Short description|Star in the constellation Centaurus}} {{Starbox begin}} {{Starbox observe | epoch = J2000.0 | constell = [[Centaurus]]<ref name=Anderson_Francis_2012/> | ra = {{RA|13|04|57.47645}}<ref name=GaiaDR2/> | dec = {{DEC|−52|26|34.5284}}<ref name=GaiaDR2/> | appmag_v = 9.05<ref name=Anderson_Francis_2012/> }} {{Starbox character | type = [[main sequence]]<ref name=reiners2020/> | class = K9Vk:<ref name=Gray_et_al_2006/> | b-v = {{val|1.362|0.009}}<ref name=Anderson_Francis_2012/> | variable = }} {{Starbox astrometry | radial_v = {{val|39.23|0.012}}<ref name="Moutou_et_al_2015"/> | prop_mo_ra = −786.038<ref name=GaiaDR2/> | prop_mo_dec = −795.591<ref name=GaiaDR2/> | parallax = 61.3899 | p_error = 0.0523 | parallax_footnote = <ref name=GaiaDR2/> | absmag_v = 8.03<ref name="Moutou_et_al_2015"/> }} {{Starbox detail | source = <ref name="Moutou_et_al_2015"/> | metal_fe = {{val|−0.24|0.06}} | mass = {{val|0.585|0.05}} | radius = {{val|0.53|0.02}} | luminosity = 0.127<ref name=GaiaDR2/> | temperature = {{val|4462|145|fmt=commas}} | gravity = {{val|3.79|0.53}} | age_gyr = {{val|4.3|4.0}} }} {{Starbox catalog | names = {{odlist | GJ2=496.1 | GJ=9425 | HD=113538 | HIP=63833 | CD=−51 7244 | LFT=966 | LHS=344 }}<ref name=SIMBAD/> }} {{Starbox reference | Simbad = HD+113538 }} {{Starbox end}}
'''HD 113538''' ('''Gliese 496.1''') is a star with two planetary companions in the southern [[constellation]] of [[Centaurus]]. It is much too faint to be viewed with the naked eye at an [[apparent visual magnitude]] of 9.05.<ref name=Anderson_Francis_2012/> The distance to this star is 53 [[light year]]s and it is drifting further away with a [[radial velocity]] of +39 km/s.<ref name="Moutou_et_al_2015"/>
This is a [[K-type main-sequence star]] of a late spectral type, [[stellar classification|classified]] as K9Vk:. It displays [[magnetic activity|chromospheric activity]] with a [[solar cycle|stellar cycle]] of at least four years and is [[metallicity|metal]] poor.<ref name="Moutou_et_al_2015"/> The star has 58.5% of the mass and 53% of the radius of the [[Sun]].<ref name="Moutou_et_al_2015"/> It is radiating just 12.7%<ref name=GaiaDR2/> of the luminosity of the Sun from its [[photosphere]] at an [[effective temperature]] of 4,462 K.<ref name="Moutou_et_al_2015"/>
== Planetary system == Radial velocity variation of HD 113538 was inferred from observations with the [[High Accuracy Radial Velocity Planet Searcher|HARPS spectrograph]]. The star is active (Log R'<sub>HK</sub> −4.697,<ref name="NStars"/> SMW 1.05<ref name="Moutou_et_al_2015"/>), but the RV variation is not correlated with activity, indicating that planets are responsible. The data is fitted well by a solution including two planets, with an eccentric Saturn-mass planet and a more massive planet on a longer-period orbit<ref name=Moutou_et_al_2011/>—similar to the orbital architecture of the planetary system orbiting [[HD 163607]], though with lower masses. Similar to HD 163607 b, the eccentricity and argument of periastron of HD 113538 b increases the planet's transit probability substantially more than it would be on a circular orbit.
{{OrbitboxPlanet begin | table_ref = <ref name=Moutou_et_al_2015/> }} {{OrbitboxPlanet | exoplanet = [[HD 113538 b|b]] | mass = {{val|0.36|0.04|p=≥ }} | period = {{val|663.2|8.4|−7.4}} | semimajor = {{val|1.24|0.04}} | eccentricity = {{val|0.14|0.08}} }} {{OrbitboxPlanet | exoplanet = [[HD 113538 c|c]] | mass = {{val|0.93|0.06|p=≥ }} | period = {{val|1818|25|22|fmt=commas}} | semimajor = {{val|2.44|0.07}} | eccentricity = {{val|0.20|0.04}} }} {{Orbitbox end}}
== References == <references> <ref name=GaiaDR2>{{Cite Gaia DR2|6080301367488384896}}</ref>
<ref name=SIMBAD>{{cite simbad | title=HD 113538 | access-date=2021-10-03 }}</ref>
<ref name=Anderson_Francis_2012>{{cite XHIP|63833}}</ref>
<ref name=Gray_et_al_2006>{{cite journal | title=Contributions to the Nearby Stars (NStars) Project: Spectroscopy of Stars Earlier than M0 within 40 pc-The Southern Sample | last1=Gray | first1=R. O. | last2=Corbally | first2=C. J. | last3=Garrison | first3=R. F. | last4=McFadden | first4=M. T. | last5=Bubar | first5=E. J. | last6=McGahee | first6=C. E. | last7=O'Donoghue | first7=A. A. | last8=Knox | first8=E. R. | display-authors=1 | journal=The Astronomical Journal | volume=132 | issue=1 | pages=161–170 | date=July 2006 | bibcode=2006AJ....132..161G | arxiv=astro-ph/0603770 | doi=10.1086/504637 | s2cid=119476992 }}</ref>
<ref name=Moutou_et_al_2011>{{citation |doi=10.1051/0004-6361/201015371 |arxiv=1012.3830 |title=The HARPS search for southern extra-solar planets: XXVI: Seven new planetary systems |last1=Moutou |first1=Claire |last2=Mayor |first2=Michel |last3=Lo Curto |first3=Gaspare |last4=Ségransan |first4=Damien |last5=Udry |first5=Stéphane |last6=Bouchy |first6=François |last7=Benz |first7=Willy |last8=Lovis |first8=Christophe |last9=Naef |first9=Dominique |last10=Pepe |first10=Francesco |last11=Queloz |first11=Didier |last12=Santos |first12=Nuno C. |last13=<!-- de -->Sousa |first13=Sérgio <!-- António -->Gonçalves |work=Astronomy & Astrophysics |s2cid=118696125 |year=2010 |volume=527 |pages=A63 }}</ref>
<ref name=Moutou_et_al_2015>{{cite journal | title=The HARPS search for southern extra-solar planets. XXXVII. Five new long-period giant planets and a system update | display-authors=1 | last1=Moutou | first1=Claire | last2=Lo Curto | first2=Gaspare | last3=Mayor | first3=Michel | last4=Bouchy | first4=François | last5=Benz | first5=Willy | last6=Lovis | first6=Christophe | last7=Naef | first7=Dominique | last8=Pepe | first8=Francesco | last9=Queloz | first9=Didier | last10=Santos | first10=Nuno C. | last11=Ségransan | first11=Damien | last12=<!-- de -->Sousa | first12=Sérgio <!-- António -->Gonçalves | last13=Udry | first13=Stéphane | journal=Astronomy & Astrophysics | volume=576 | id=A48 | pages=14 | date=April 2015 | arxiv=1412.6591 | bibcode=2015A&A...576A..48M | doi=10.1051/0004-6361/201424965 }}</ref>
<ref name="NStars">{{cite journal | title=Contributions to the Nearby Stars (NStars) Project: Spectroscopy of Stars Earlier than M0 within 40 pc-The Southern Sample | last1=Gray | first1=R. O. | last2=Corbally | first2=C. J. | last3=Garrison | first3=R. F. | last4=McFadden | first4=M. T. | last5=Bubar | first5=E. J. | last6=McGahee | first6=C. E. | last7=O'Donoghue | first7=A. A. | last8=Knox | first8=E. R. | display-authors=1 | journal=The Astronomical Journal | volume=132 | issue=1 | pages=161–170 | date=July 2006 | doi=10.1086/504637 | bibcode=2006AJ....132..161G | arxiv=astro-ph/0603770 | s2cid=119476992 }}</ref>
<ref name=reiners2020>{{cite journal |last1=Reiners |first1=Ansgar |last2=Zechmeister |first2=Mathias |title=Radial Velocity Photon Limits for the Dwarf Stars of Spectral Classes F-M |journal=The Astrophysical Journal Supplement Series |date=2020 |volume=247 |issue=1 |page=11 |doi=10.3847/1538-4365/ab609f |doi-access=free |arxiv=1912.04120 |bibcode=2020ApJS..247...11R }}</ref> </references>
{{Stars of Centaurus}}
{{DEFAULTSORT:HD 113538}} <!-- Properties --> [[Category:K-type main-sequence stars]] [[Category:Planetary systems with two confirmed planets]] <!-- Other --> [[Category:Centaurus]] [[Category:Durchmusterung objects]] [[Category:Gliese and GJ objects|9425]] [[Category:Henry Draper Catalogue objects|113538]] [[Category:Hipparcos objects|063833]]