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| {{Starbox begin
| | Nothing to tell about myself I think.<br>Feels good to be a part of wmflabs.org.<br>I really wish I am useful at all |
| | name=Kepler-46}}
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| {{Starbox image |
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| | image = [[File:KOI-872 system.jpg|250px]]
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| | caption = Artist's conception of the Kepler-46 system showing the two planets. Planet b transits its star, the same method by which it was detected.<!--include notice http://www.swri.org/2about/copy.htm-->
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| }}
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| {{Starbox observe
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| | epoch=J2000
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| | ra= {{RA|19|17|4.449}}<ref name=simbad>{{cite web | url=http://simbad.u-strasbg.fr/simbad/sim-id?protocol=html&Ident=KOI-872 | title=Basic data: 2MASS J19170449+4236150
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| | publisher=University of Stratsbourg | work=SIMBAD | year=2012 | accessdate=May 16, 2012}}</ref>
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| | dec= {{DEC|42|36|15.03}}<ref name=simbad />
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| | constell=[[Cygnus (constellation)|Cygnus]]
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| | appmag_v =
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| }}
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| {{Starbox character
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| | class = Unknown<!-- NOTE: Please don't add a 'V' here until it is established as such by a reliable source. -->
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| | appmag_1_passband =
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| | appmag_1 =
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| | appmag_2_passband =
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| | appmag_2 =
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| | appmag_3_passband =
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| | appmag_3 = 13.814<ref name=simbad />
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| | appmag_4_passband = H
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| | appmag_4 = 13.436<ref name=simbad />
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| | appmag_5_passband = K
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| | appmag_5 = 13.347<ref name=simbad />
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| | r-i = <!--R-I color-->
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| | v-r = <!--V-R color-->
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| | b-v = <!--B-V color-->
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| | u-b = <!--U-B color-->
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| | variable = <!--Variability type-->
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| }}
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| {{Starbox astrometry
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| | radial_v=
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| | prop_mo_ra=
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| | prop_mo_dec=
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| | gal_lat=
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| | gal_lon=
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| | parallax=
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| | p_error=
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| | dist_ly=2795 ± 226
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| | dist_pc=857 ± 69
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| | absmag_bol=5.18 (predicted)<ref group=note>Figure based on the following equations, which calculated ''bolometric'' (total) luminosity across all spectra based on effective temperature: <math>m_{\rm star}=m_{\rm sun}-2.5\log_{10}\left({ L_{\rm star} \over L_{\odot} } \cdot \left(\frac{ d_{\rm sun} }{ d_{\rm star} }\right)^2\right)</math> (''cf.'' [[Luminosity]]) and <math> M = m_{\rm star} - 5 ((\log_{10}{D_L}) - 1)\!\,</math> (''cf.'' [[Absolute magnitude]])</ref>
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| }}
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| {{Starbox detail
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| | mass={{nowrap|0.902 ± 0.04}}<ref name=epe/>
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| | luminosity_bolomatric=0.868 ± 0.155 (predicted)<ref group=note>The equation used to calculate this was : <math>\frac{L}{L_{\odot}} = {\left ( \frac{R}{R_{\odot}} \right )}^2 {\left ( \frac{T}{T_{\odot}} \right )}^4</math>.</ref>
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| | habitable zone=
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| | temperature={{nowrap|5155 ± 105}}<ref name=epe/>
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| | metal_fe={{nowrap|0.41 ± 0.1}}<ref name=epe /><ref group=note>This measurement indicates the log<sub>10</sub> of the relative abundance of iron in the measured star to that of the Sun.</ref>
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| | radius={{nowrap|0.94 ± 0.04}}<ref name=epe/>
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| | rotational_velocity=
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| | age_gyr={{nowrap|9.9 <sup>+3.5</sup><sub>-3.1</sub>}}<ref name=epe/>
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| }}
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| {{Starbox catalog
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| | names=[[2MASS]] J19170449+4236150, [[Kepler Input Catalog|KIC]] 7109675<ref name=simbad />}}
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| {{Starbox end}}'''Kepler-46''', previously designated '''KOI-872''', is a [[star]] located in the constellation [[Cygnus (constellation)|Cygnus]]. Observed since 2009 by the [[Kepler (spacecraft)|Kepler space observatory]], it has since been found to possess a [[planetary system]] consisting of at least two planets and while it has a similar mass to the Sun (90%) it is significantly older at ten billion years.<ref name=epe>{{cite web | url=http://exoplanet.eu/star.php?st=Kepler-46 | title=Notes for Star Kepler-46 | work=Extrasolar Planets Encyclopaedia | accessdate=May 16, 2012 | author=Schneider, Jean}}</ref>
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| Kepler-46 b (previously KOI-872.01), was the first planet discovered in the system. It was found through detailed analysis of Kepler space observatory data. An additional planet, Kepler-46 c, was discovered by an outside group using Kepler public data through analysis of [[Transit_Timing_Variation#Transit_timing_variation_method|transit timing variation]]s. While only one additional planet was confirmed by the analysis, the study revealed the potential existence of either an unconfirmed planet KOI-872.03 (KOI-872 d){{fact|date=May 2013}} or an [[extrasolar moon]]{{fact|date=May 2013}}, which if confirmed would be the first-ever moon discovered outside the Solar System.{{fact|date=May 2013}}
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| == Planetary system ==
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| Planet b is a superjovian gas giant with 6 times the mass of Jupiter. The second planet in the system was among the first to be discovered through the method of [[Transit_Timing_Variation#Transit_timing_variation_method|transit timing variation]]s, and through its confirmation of KOI-872 c with a 99% confidence level has shown that the method of detection may be used to detect future [[extrasolar planet]]s and, possibly, [[extrasolar moon]]s.<ref name=space.com>{{cite news | url=http://www.space.com/15631-hidden-alien-planet-gravity-discovery.html | title=Hidden Alien Planet Revealed by Its Own Gravity| work=Space.com | date=May 10, 2012 | agency=Space.com | accessdate=May 10, 2012 | author=Moskowitz, Clara}}</ref> This second planet exerted a gravitational force on the first planet, orbiting its host star in just 34 days. While this usually occurs on an extremely regular schedule, additional planets within the system can disrupt the time of the transit, and these disruptions can indicate the presence of a planet, even if the disrupting planet does not pass in front of the host star itself.<ref name=space.com />
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| The data show that Kepler-46 c is an approximately Saturn-mass object with an orbital period of 57 days.<ref name=space.com /> As the planet does not itself transit its host star, there is no way of knowing its size (probably a similar size to its sibling). The measurements also suggest the existence of another planet orbiting with a period of about 6.8 days, but this planet is unconfirmed.<ref name=epe />
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| The method in which the planet was detected is similar to the way that the planet Neptune was discovered, in which the newly discovered planet is known by its pull on another which is already known to exist.<ref name=crockett-2012>{{cite news | url=http://earthsky.org/space/new-planet-found-in-distant-solar-system-by-its-tug-on-another-world | title=New planet found in distant solar system by its tug on another world | work=EarthSky | date=May 12, 2012 | agency=Earthsky Communications | accessdate=May 19, 2012 | author=Crockett, Cristopher}}</ref>
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| {{Orbitbox planet begin|table_ref=<ref name=epe />}}
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| {{OrbitboxPlanet
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| |exoplanet = b
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| | mass = <6
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| | radius = 0.812 ± 0.043
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| | semimajor = 0.1967 ± 0.0029
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| | period = 33.60134 ± 0.00021
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| | eccentricity = 0.01 ± 0.01}}
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| {{OrbitboxPlanet
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| |exoplanet = c
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| | mass = 0.376 ± 0.023
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| | semimajor = 0.2799 ± 0.0041
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| | period = 57.004 <sup>+0.091</sup><sub>-0.1</sub>
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| | eccentricity = 0.01 ± 0.01 }}
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| {{OrbitboxPlanet hypothetical
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| |exoplanet = d
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| | mass =
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| | semimajor = 0.068 ± 0.003
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| | period = 6.76671 ± 0.00013
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| | eccentricity =
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| | radius = 0.1513 ± 0.0089 }}
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| {{Orbitbox end}}
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| == References ==
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| {{Reflist}}
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| == Notes ==
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| {{reflist|group=note}}
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| <!--[http://www.google.com/search?client=safari&rls=en&q=koi-872&ie=UTF-8&oe=UTF-8#q=koi-872&hl=en&safe=active&client=safari&rls=en&prmd=imvnsu&source=lnms&tbm=nws&ei=s62uT46RLsjMiQKNwOXkAw&sa=X&oi=mode_link&ct=mode&cd=5&ved=0CBYQ_AUoBA&bav=on.2,or.r_gc.r_pw.r_cp.r_qf.,cf.osb&fp=b6e4e9ed7cba883e&biw=1280&bih=675 Google News search for KOI-872]-->
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| {{Stars of Cygnus}}
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| [[Category:Cygnus (constellation)]]
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| [[Category:Articles created via the Article Wizard]]
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| [[Category:Exoplanets]]
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| [[Category:Kepler Objects of Interest]]
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| [[Category:Planetary transit variables]]
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Nothing to tell about myself I think.
Feels good to be a part of wmflabs.org.
I really wish I am useful at all