{{Short description|Star in the constellation Centaurus}} {{Starbox begin}} {{Starbox observe | epoch = J2000.0 | constell = [[Centaurus]]<ref name=Anderson_Francis_2012/> | ra = {{RA|11|52|52.97819}}<ref name=GaiaDR3/> | dec = {{DEC|−50|17|34.1616}}<ref name=GaiaDR3/> | appmag_v = 9.40<ref name=Anderson_Francis_2012/> }} {{Starbox character | type = [[main sequence]]<ref name=GaiaDR3/> | class = K1V(p)<ref name=houk1978/> | appmag_1_passband = B | appmag_1 = 10.26<ref name=Anderson_Francis_2012/> | appmag_2_passband = J | appmag_2 = {{val|7.916|0.023}}<ref name=Anderson_Francis_2012/> | appmag_3_passband = H | appmag_3 = {{val|7.600|0.051}}<ref name=Anderson_Francis_2012/> | appmag_4_passband = K | appmag_4 = {{val|7.426|0.027}}<ref name=Anderson_Francis_2012/> | b-v = {{val|0.860|0.023}}<ref name=Anderson_Francis_2012/> | u-b = | variable = }} {{Starbox astrometry | radial_v = {{val|−4.37|0.14}}<ref name=GaiaDR3/> | prop_mo_ra = −80.925<ref name=GaiaDR3/> | prop_mo_dec = +7.353<ref name=GaiaDR3/> | parallax = 17.5507 | p_error = 0.0142 | parallax_footnote = <ref name=GaiaDR3/> | absmag_v = 5.79<ref name=Anderson_Francis_2012/> }} {{Starbox detail | source = | mass = 0.90<ref name="Mordasini2011"/> | radius = 0.93<ref name=GaiaDR3/> | gravity = {{val|4.40|0.11}}<ref name="Mordasini2011"/> | luminosity = 0.54<ref name=GaiaDR3/> | temperature = {{val|5303|58|fmt=commas}}<ref name="Mordasini2011"/> | metal_fe = {{val|0.21|0.04}}<ref name="Mordasini2011"/> | rotational_velocity = 0.602<ref name=Costa_Silva_et_al_2020/> | rotation = {{val|51|5|u=days}}<ref name="Mordasini2011"/> | age_gyr = {{val|4.872|4.294}}<ref name=Costa_Silva_et_al_2020/> }} {{Starbox catalog | names = {{odlist | CD=−49°6573 | HD=103197 | HIP=57931 | PPM=769972 }} }} {{Starbox reference | Simbad = HD+103197 | NSTED = HD 103197 | EPE = HD+103197 }} {{Starbox end}}

'''HD 103197''' is a [[star]] with a planetary companion in the southern [[constellation]] of [[Centaurus]]. It has an [[apparent visual magnitude]] of 9.40, which is too faint to be viewed with the naked eye. Based on [[stellar parallax|parallax]] measurements, HD 103197 is located at a distance of 187&nbsp;[[light year]]s from the [[Sun]]. It is drifting closer with a [[radial velocity]] of −4.6&nbsp;km/s.

This is a [[K-type main-sequence star]] with a [[stellar classification]] of K1V(p). In 1978, [[Nancy Houk|N. Houk]] noted that the cores of the star's [[H and K lines]] are weakly in emission; hence the 'p' code indicating a spectral peculiarity.<ref name=houk1978/> The star is an estimated five&nbsp;billion years old with a [[projected rotational velocity]] of approximately 0.6&nbsp;km/s<ref name=Costa_Silva_et_al_2020/> and it appears to be [[magnetic activity|very inactive]]. It has 90% of the mass and 95% of the radius of the Sun. Its [[metallicity|metal]] content is five-eighths greater than in the Sun.<ref name="Mordasini2011"/>

In 2009, a [[gas giant]] [[exoplanet]] companion was discovered using the [[radial velocity]] method. This object is orbiting the host star at a distance of {{convert|0.249|AU|Gm|lk=on|abbr=on}} and a period of {{val|47.84|u=days}}, with what is assumed to be a circular orbit.<ref name="Mordasini2011"/>

{{OrbitboxPlanet begin | table_ref = <ref name="Mordasini2011"/> }} {{OrbitboxPlanet | exoplanet = [[HD 103197 b|b]] | mass_earth = ≥31.2 ± 2.0 | period = 47.84 ± 0.03 | semimajor = 0.249 ± 0.004 | eccentricity = 0.0(fixed) }} {{Orbitbox end}}

== See also == * [[List of extrasolar planets]]

== References == {{Reflist|refs=

<ref name=GaiaDR3>{{Cite Gaia DR3|5370827127297364480}}</ref>

<ref name=Anderson_Francis_2012>{{cite XHIP|57931}}</ref>

<ref name="Mordasini2011">{{cite journal | title=The HARPS search for southern extrasolar planets XXIV. Companions to HD 85390, HD 90156, and HD 103197: a Neptune analog and two intermediate-mass planets | url=http://www.aanda.org/articles/aa/full_html/2011/02/aa13521-09/aa13521-09.html | last1=Mordasini | first1=C. | last2=Mayor | first2=M. | last3=Udry | first3=S. | last4=Lovis | first4=C. | last5=Ségransan | first5=D. | last6=Benz | first6=W. | last7=Bertaux | first7=J.-L. | last8=Bouchy | first8=F. | last9=Curto | first9=G. Lo | last10=Moutou | first10=C. | last11=Naef | first11=D. | last12=Pepe | first12=F. | last13=Queloz | first13=D. | last14=Santos | first14=N. C. | display-authors=1 | journal=Astronomy and Astrophysics | volume=526 | at=A111 | date=2011 | arxiv=1010.0856 | bibcode=2011A&A...526A.111M | doi=10.1051/0004-6361/200913521 | s2cid=59062607 }}</ref>

<ref name=houk1978>{{cite book | last1=Houk | first1=Nancy | title=Michigan catalogue of two-dimensional spectral types for the HD stars | volume=2 | location=Ann Arbor | publisher=Dept. of Astronomy, University of Michigan | year=1978 | bibcode=1978mcts.book.....H }}</ref>

<ref name=Costa_Silva_et_al_2020>{{cite journal | title=Chemical abundances of 1111 FGK stars from the HARPS-GTO planet search sample. III. Sulfur | display-authors=1 | last1=Costa Silva | first1=A. R. | last2=Delgado Mena | first2=E. | last3=Tsantaki | first3=M. | journal=Astronomy & Astrophysics | volume=634 | id=A136 | pages=10 | date=February 2020 | doi=10.1051/0004-6361/201936523 | arxiv=1912.08659 | bibcode=2020A&A...634A.136C | s2cid=209405391 }}</ref>

}}

{{Sky|11|52|52.9787|-|50|17|34.160|160.9}} {{Stars of Centaurus}} {{DEFAULTSORT:HD 103197}} <!-- Properties --> [[Category:K-type main-sequence stars]] [[Category:Planetary systems with one confirmed planet]] <!-- Other --> [[Category:Centaurus]] [[Category:Durchmusterung objects|CD-49 06573]] [[Category:Henry Draper Catalogue objects|103197]] [[Category:Hipparcos objects|057931]]