View source for KOI-5

{{Starbox begin
| name = KOI-5
}}
{{Starbox observe
| epoch = J2000
| equinox = <!--Equinox of coordinates (defaults to epoch)-->
| constell = [[Cygnus (constellation)|Cygnus]]
| pronounce = <!--Pronunciation guide-->
| ra = {{RA|19|18|57.5312}}
| dec = {{DEC|+44|38|50.6176}}
| appmag_v = <!--Apparent magnitude (Johnson-Cousins V  system)-->
}}{{^|
{{Starbox character
| engvar = en-UK <!-- for articles written in variants of English where "colour" is the correct spelling -->
| component1 = <!--Name of the first component-->
| type = <!--Type of star (e.g., main sequence star, protostar, white dwarf, neutron star, etc.)-->
| class = <!--Stellar class-->
| appmag_1_passband = <!-- Passband for first apparent magnitude (e.g., H, J, K, etc.) -->
| appmag_1 = <!-- Value of first apparent magnitude  -->
| appmag_2_passband = <!-- Passband for second apparent magnitude (e.g., H, J, K, etc.) -->
| appmag_2 = <!-- Value of second apparent magnitude  -->
| appmag_3_passband = <!-- Passband for third apparent magnitude (e.g., H, J, K, etc.) -->
| appmag_3 = <!-- Value of third apparent magnitude  -->
| appmag_4_passband = <!-- Passband for fourth apparent magnitude (e.g., H, J, K, etc.) -->
| appmag_4 = <!-- Value of fourth apparent magnitude  -->
| appmag_5_passband = <!-- Passband for fifth apparent magnitude (e.g., H, J, K, etc.) -->
| appmag_5 = <!-- Value of fifth apparent magnitude  -->
| appmag_6_passband = <!-- Passband for sixth apparent magnitude (e.g., H, J, K, etc.) -->
| appmag_6 = <!-- Value of sixth apparent magnitude  -->
| appmag_7_passband = <!-- Passband for seventh apparent magnitude (e.g., H, J, K, etc.) -->
| appmag_7 = <!-- Value of seventh apparent magnitude  -->
| appmag_8_passband = <!-- Passband for eighth apparent magnitude (e.g., H, J, K, etc.) -->
| appmag_8 = <!-- Value of eighth apparent magnitude  -->
| r-i = <!--R−I color-->
| v-r = <!--V−R color-->
| b-v = <!--B−V color-->
| u-b = <!--U−B color-->
| j-h = <!--J−H color-->
| j-k = <!--J−K color-->
| variable = <!--Variability type-->
| component2 = <!--Name of the second component-->
| type2 = <!--Type of star (e.g., main sequence star, protostar, white dwarf, neutron star, etc.)-->
| class2 = <!--Stellar class-->
| appmag_1_passband2 = <!-- Passband for first apparent magnitude (e.g., H, J, K, etc.) -->
| appmag_1_2 = <!-- Value of first apparent magnitude  -->
| appmag_2_passband2 = <!-- Passband for second apparent magnitude (e.g., H, J, K, etc.) -->
| appmag_2_2 = <!-- Value of second apparent magnitude  -->
| appmag_3_passband2 = <!-- Passband for third apparent magnitude (e.g., H, J, K, etc.) -->
| appmag_3_2 = <!-- Value of third apparent magnitude  -->
| appmag_4_passband2 = <!-- Passband for fourth apparent magnitude (e.g., H, J, K, etc.) -->
| appmag_4_2 = <!-- Value of fourth apparent magnitude  -->
| appmag_5_passband2 = <!-- Passband for fifth apparent magnitude (e.g., H, J, K, etc.) -->
| appmag_5_2 = <!-- Value of fifth apparent magnitude  -->
| appmag_6_passband2 = <!-- Passband for sixth apparent magnitude (e.g., H, J, K, etc.) -->
| appmag_6_2 = <!-- Value of sixth apparent magnitude  -->
| appmag_7_passband2 = <!-- Passband for seventh apparent magnitude (e.g., H, J, K, etc.) -->
| appmag_7_2 = <!-- Value of seventh apparent magnitude  -->
| appmag_8_passband2 = <!-- Passband for eighth apparent magnitude (e.g., H, J, K, etc.) -->
| appmag_8_2 = <!-- Value of eighth apparent magnitude  -->
| r-i2 = <!--R−I color-->
| v-r2 = <!--V−R color-->
| b-v2 = <!--B−V color-->
| u-b2 = <!--U−B color-->
| j-h2 = <!--J−H color-->
| j-k2 = <!--J−K color-->
| variable2 = <!--Variability type-->
}}}}
{{Starbox astrometry
 | radial_v = -35.16<ref name=EDR3>{{cite Gaia EDR3|2126945668448657664}}</ref>
 | total_v = <!--Total velocity (radial velocity combined with proper motion in km/sec)-->
 | prop_mo_ra = 3.216<ref name=EDR3/>
 | prop_mo_dec = -10.925<ref name=EDR3/>
 | parallax = 1.7436
 | p_error = 0.0666
 | parallax_footnote = <ref name=EDR3/>
 | dist_ly = 
 | dist_pc = <!--Distance (in parsecs)-->
 | absmag_v = <!--Absolute magnitude ([[UBV photometric system|Johnson-Cousins V system]])-->
 | absmag_bol = <!--Absolute bolometric magnitude (accounts for emissions across all spectra of light)-->
 }}
{{Starbox relpos
| reference = <ref name=Furlan2016>{{citation |arxiv=1612.02392 |doi=10.3847/1538-3881/153/2/71 |title=The Kepler Follow-Up Observation Program. I. A Catalog of Companions To Kepler Stars from High-Resolution Imaging |year=2017 |last1=Furlan |first1=E. |last2=Ciardi |first2=D. R. |last3=Everett |first3=M. E. |last4=Saylors |first4=M. |last5=Teske |first5=J. K. |last6=Horch |first6=E. P. |last7=Howell |first7=S. B. |last8=Van Belle |first8=G. T. |last9=Hirsch |first9=L. A. |last10=Gautier |first10=T. N. |last11=Adams |first11=E. R. |last12=Barrado |first12=D. |last13=Cartier |first13=K. M. S. |last14=Dressing |first14=C. D. |last15=Dupree |first15=A. K. |last16=Gilliland |first16=R. L. |last17=Lillo-Box |first17=J. |last18=Lucas |first18=P. W. |last19=Wang |first19=J. |journal=The Astronomical Journal |volume=153 |issue=2 |page=71 |bibcode=2017AJ....153...71F |s2cid=38339900 |doi-access=free }}</ref>
| epoch = 2016
| primary = KOI-5A
| component = KOI-5B
| angdistsec =  0.029{{±|0.050}}
| angdistref = <!--Reference for angular distance -->
| posang = 142.1{{±|1.0}}
| posangref = <!--Reference for position angle -->
| projsep = 16{{cn|date=January 2021}}
| projsepref = <!--Reference for projected separation -->
}}
{{Starbox relpos
| reference = <ref name=Furlan2016/>
| epoch = 2016
| primary = KOI-5A
| component = KOI-5C
| angdistsec =  0.141{{±|0.050}}
| angdistref = <!--Reference for angular distance -->
| posang = 304.3{{±|2.2}}
| posangref = <!--Reference for position angle -->
| projsep = 78{{cn|date=January 2021}}
| projsepref = <!--Reference for projected separation -->
}}
{{Starbox detail
| source                 =   <ref>{{citation |arxiv=1812.06979 |doi=10.1051/0004-6361/201834461 |title=Stellar ages, masses, and radii from asteroseismic modeling are robust to systematic errors in spectroscopy |year=2020 |last1=Bellinger |first1=E. P. |last2=Hekker |first2=S. |last3=Angelou |first3=G. C. |last4=Stokholm |first4=A. |last5=Basu |first5=S. |journal=Astronomy & Astrophysics |volume=622 |pages=A130 |s2cid=119293351 }}</ref>
| component1             =   KOI-5A
| mass                   =   1.13<ref name=Ciardi2021/>
| radius                 =   1.840{{±|0.017}}
| luminosity             =   3.86{{±|0.17}}
| gravity                =   4.19<ref name=Batalha2012>{{citation |arxiv=1202.5852 |doi=10.1088/0067-0049/204/2/24 |title=Planetary Candidates Observed by Kepler . III. Analysis of the First 16 Months of Data |year=2013 |last1=Batalha |first1=Natalie M. |last2=Rowe |first2=Jason F. |last3=Bryson |first3=Stephen T. |last4=Barclay |first4=Thomas |last5=Burke |first5=Christopher J. |last6=Caldwell |first6=Douglas A. |last7=Christiansen |first7=Jessie L. |last8=Mullally |first8=Fergal |last9=Thompson |first9=Susan E. |last10=Brown |first10=Timothy M. |last11=Dupree |first11=Andrea K. |last12=Fabrycky |first12=Daniel C. |last13=Ford |first13=Eric B. |last14=Fortney |first14=Jonathan J. |last15=Gilliland |first15=Ronald L. |last16=Isaacson |first16=Howard |last17=Latham |first17=David W. |last18=Marcy |first18=Geoffrey W. |last19=Quinn |first19=Samuel N. |last20=Ragozzine |first20=Darin |last21=Shporer |first21=Avi |last22=Borucki |first22=William J. |last23=Ciardi |first23=David R. |last24=Gautier |first24=Thomas N. |last25=Haas |first25=Michael R. |last26=Jenkins |first26=Jon M. |last27=Koch |first27=David G. |last28=Lissauer |first28=Jack J. |last29=Rapin |first29=William |last30=Basri |first30=Gibor S. |journal=The Astrophysical Journal Supplement Series |volume=204 |issue=2 |page=24 |bibcode=2013ApJS..204...24B |s2cid=19023502 |display-authors=29 }}</ref>
| temperature            =   5861<ref name=Batalha2012/>
| metal                  =   <!--Metallicity (no units provided by template)-->
| metal_fe               =   <!--Metallicity ([Fe/H] dex) -->
| rotation               =   <!--Rotation (no units provided by template)-->
| rotational_velocity    =   <!--Rotational velocity (v sin i, in km/s)-->
| age_gyr                =   3.49{{±|0.41}}
| component2             =   KOI-5B
| mass2                  =   1.09<ref name=Ciardi2021/>
| radius2                =   <!--Radius (in solar radii)-->
| luminosity2            =   <!--Luminosity (in solar luminosities); prefer luminosity_bolometric or luminosity_visual-->
| gravity2               =   <!--Surface gravity (given as the base 10 logarithm expressed in cgs units)-->
| temperature2           =   <!--Effective temperature (in kelvins)-->
| metal2_fe              =   <!--Metallicity ([Fe/H] dex) -->
| rotation2              =   <!--Rotation (no units provided by template)-->
| rotational_velocity2   =   <!--Rotational velocity (v sin i, in km/s)-->
| age_gyr2               =   <!--Age (in billions of years)-->
}}
{{Starbox catalog
 | names      = TOI-1241, [[2MASS]] J19185753+4438507, KIC 8554498, Gaia EDR3 2126945668448657664
 | component1 = KOI-5A
 | names1     = 
 | component2 = KOI-5B
 | names2     = 
 | component3 = <!-- Double star component 3 primary designation -->
 | names3     = KOI-5C
 | component4 = <!-- Double star component 3 primary designation -->
 | names4     = <!-- Other catalog designations for component 4-->
}}
{{Starbox reference
 | Simbad = KOI-5
}}
{{Starbox end}}

'''KOI-5''' is a [[triple star system]] composed of three stars: KOI-5 A, KOI-5 B and KOI-5 C, orbiting 1,870{{±|70}} light-years away. 

The two dim stellar companions to KOI-5A were discovered in 2016.<ref name=Furlan2016/> KOI-5 A and B orbit each other every 29 years, and KOI-5 C orbits stars A and B every 400 years.<ref name=Ciardi2021/>  KOI-5C is physically associated with the core stellar pair with probability 99.98%.<ref name=Kirsch2017>{{citation |arxiv=1701.06577 |doi=10.3847/1538-3881/153/3/117 |title=Assessing the Effect of Stellar Companions from High-resolution Imaging of Kepler Objects of Interest |year=2017 |last1=Hirsch |first1=Lea A. |last2=Ciardi |first2=David R. |last3=Howard |first3=Andrew W. |last4=Everett |first4=Mark E. |last5=Furlan |first5=Elise |last6=Saylors |first6=Mindy |last7=Horch |first7=Elliott P. |last8=Howell |first8=Steve B. |last9=Teske |first9=Johanna |last10=Marcy |first10=Geoffrey W. |journal=The Astronomical Journal |volume=153 |issue=3 |page=117 |bibcode=2017AJ....153..117H |s2cid=39321033 |doi-access=free }}</ref>

==Planetary system==
Two planets orbiting one of KOI-5's stars were suspected since 2009 based on [[Kepler space telescope|Kepler]] data, but [[KOI-5Ab]] was confirmed only in January 2021 after [[Transiting Exoplanet Survey Satellite|TESS]] determined the planet is orbiting KOI-5A. The exoplanet has caused interest in the scientific community because its orbital plane is misaligned with the closer star, suggesting it gave KOI-5Ab a gravitational kick during its development, resulting in the misalignment and inward migration to the current orbit.<ref name=Ciardi2021>[https://aas.org/sites/default/files/2021-01/AAS237_Mon2_Ciardi.pdf AT LAST! CONFIRMATION OF KEPLER'S SECOND PLANETARY CANDIDATE]</ref><ref name="NASA">{{Cite web|last=Chen|first=Rick|date=2021-01-11|title=Planetary Sleuthing Finds Triple-Star World|url=http://www.nasa.gov/feature/ames/planetary-sleuthing-finds-triple-star-world|access-date=2021-01-13|website=NASA}}</ref> However, the confirmation of this planet has yet to be published in any peer-reviewed journal.

A second candidate planet was initially suspected, but was later found to be a false positive.<ref name="Archive" />

{{OrbitboxPlanet begin
| name = KOI-5A
| table_ref = <ref name=Kirsch2017/><ref name=Ciardi2021/><ref name="Archive">{{Cite web|title=Exoplanet Archive|url=https://exoplanetarchive.ipac.caltech.edu/overview/KOI-5.02#planet_KOI-5-02_collapsible|access-date=2021-07-17|website=exoplanetarchive.ipac.caltech.edu}}</ref>
| period_unit = day
}}
{{OrbitboxPlanet
| exoplanet = b
| mass = 0.179
| mass_earth = <!--Mass of the planet, in Earth masses (can use mass instead)-->
| radius = <!-- Radius of the planet, in Jupiter radii -->
| radius_earth = 7.07
| semimajor = 0.0596060
| period = 5
| eccentricity = <!--Eccentricity of the planet-->
| inclination = <!-- Orbital inclination (to the line of sight) -->
}}
{{Orbitbox end}}

== References ==
{{Reflist}}
{{Sky|19|18|57.5312|+|44|38|50.6176}}
{{Cygnus (constellation)}}
{{2021 in space}}{{main-star-stub}}
{{multi-star-stub}}{{Extrasolar-planet-stub}}
[[Category:Cygnus (constellation)]]
[[Category:G-type main-sequence stars]]
[[Category:Kepler objects of interest|0005]]
[[Category:Planetary systems with one confirmed planet]]
[[Category:2MASS objects|J19185753+4438507]]
[[Category:Triple star systems]]
[[Category:Planetary transit variables]]