View source for 47 Ursae Majoris

{{short description|Star in the constellation Ursa Major}}
{{good article}}
{{Starbox begin
| name = 47 Ursae Majoris / Chalawan
}}
{{Starbox image
| image = [[File:47 UMa-starmap.png|320px]]
| caption = Location of 47 Ursae Majoris in [[Ursa Major (constellation)|Ursa Major]]
}}
{{Starbox observe
| epoch = J2000.0
| constell = [[Ursa Major]]
| ra = {{RA|10|59|27.9728}}<ref name="GaiaDR3"/>
| dec = {{DEC|+40|25|48.921}}<ref name="GaiaDR3"/>
| appmag_v = +5.03
}}
{{Starbox character
| class = G1V
| r-i = 
| v-r = 
| b-v = 0.61
| u-b = 0.13
}}
{{Starbox astrometry
| radial_v = {{val|11.24|(12)}}<ref name="GaiaDR3"/>
| prop_mo_ra = {{val|−316.850|(97)}}
| prop_mo_dec = {{val|55.180|(118)}}
| pm_footnote = <ref name="GaiaDR3"/>
| parallax = 72.0070
| p_error = 0.0974
| parallax_footnote = <ref name="GaiaDR3"/>
| absmag_v = 4.41<ref name=aaa343_222/>
}}
{{Starbox detail
| mass = 1.08<ref name="cne_stars">
{{cite web
 |title       = Stars Table
 |url         = http://exoplanets.org/stars.shtml
 |work        = [[Catalog of Nearby Exoplanets]]
 |access-date  = 2008-10-04
 |archive-url  = https://web.archive.org/web/20081017112415/http://exoplanets.org/stars.shtml
 |archive-date = 17 October 2008
 |url-status     = dead
}}</ref>
| radius = 1.172 ± 0.111<ref name="Belle">
{{cite journal
 | author=G. T. van Belle
 | author2=K. von Braun
 | date=2009
 | title=Directly Determined Linear Radii and Effective Temperatures of Exoplanet Host Stars
 | journal=[[Astrophysical Journal]]
 | volume=694 | issue=2 | pages=1085–1098
 | doi=10.1088/0004-637X/694/2/1085
 | bibcode=2009ApJ...694.1085V
| arxiv=0901.1206
| s2cid=18370219
 }}</ref>
| temperature = 5,887 ± 3.8<ref>
{{cite journal
 | author=V. V. Kovtyukh
 | date=2003
 | title=High precision effective temperatures for 181 F-K dwarfs from line-depth ratios
 | journal=[[Astronomy and Astrophysics]]
 | volume=411 | issue=3 | pages=559–564
 | doi=10.1051/0004-6361:20031378
| bibcode=2003A&A...411..559K
|arxiv = astro-ph/0308429
 | last2=Soubiran
 | first2=C.
 | last3=Belik
 | first3=S. I.
 | last4=Gorlova
 | first4=N. I. | s2cid=18478960
 | display-authors=2
 }}</ref>
| luminosity = 1.48<ref name=bolometric_luminosity group=note/>
| metal = 110% solar<ref name="cne_stars"/>
| rotational_velocity = 2.80<ref name="cne_stars"/>
| gravity = 4.377<ref name="cne_stars"/>
| age_gyr = 6.03<ref name="saffe05">
{{cite journal
 |author=C. Saffe
 |date=2005
 |title=On the Ages of Exoplanet Host Stars
 |journal=[[Astronomy and Astrophysics]]
 |volume=443 |issue=2 |pages=609–626
 |bibcode=2005A&A...443..609S
 |doi=10.1051/0004-6361:20053452
|arxiv = astro-ph/0510092
 |last2=Gómez
 |first2=M.
 |last3=Chavero
 |first3=C. |s2cid=11616693
 |display-authors=2
 }}</ref>
}}
{{Starbox catalog
| names = Chalawan, [[Durchmusterung|BD]]+41°2147, [[Catalogues of Fundamental Stars|FK5]] 1282, [[Boss General Catalogue|GC]] 15087, [[General Catalogue of Trigonometric Parallaxes|GCTP]] 2556.00, [[Gliese Catalogue of Nearby Stars|Gliese]] 407, [[Henry Draper catalogue|HD]] 95128, [[Hipparcos catalogue|HIP]] 53721, [[Harvard Revised catalogue|HR]] 4277, [[Luyten Two-Tenths catalogue|LTT]] 12934, [[Smithsonian Astrophysical Observatory Star Catalog|SAO]] 43557
}}
{{Starbox reference
| Simbad = 47+UMa|sn=The star
| Simbad2 =*+47+UMa+b|sn2=planet b
| Simbad3 =*+47+UMa+c|sn3=planet c
| Simbad4 =*+47+UMa+d|sn4=planet d
| EPE = 47+UMa
| NSTED = 47+UMa
| ARICNS = 00833
}}
{{Starbox end}}

'''47 Ursae Majoris''' (abbreviated '''47 UMa'''), formally named '''Chalawan''' {{IPAc-en|'|tʃ|ɑː|l|@|w|@|n}},<ref name="IAU-CSN">{{cite web | url=http://www.pas.rochester.edu/~emamajek/WGSN/IAU-CSN.txt | title=IAU Catalog of Star Names |access-date=28 July 2016}}</ref><ref>Thai Astronomical Society, [http://thaiastro.nectec.or.th/library/article/191/ Chalawan, Taphao Thong, Taphao Kaew – First Thai Exoworld Names]</ref> is a [[yellow dwarf star]] approximately 45.3 [[light-year]]s<ref name="GaiaDR3"/> from Earth in the [[constellation]] of [[Ursa Major]]. {{As of|2011}}, three [[extrasolar planet]]s (designated [[47 Ursae Majoris b]], [[47 Ursae Majoris c|c]] and [[47 Ursae Majoris d|d]]; the first two later named Taphao Thong and Taphao Kaew) are believed to orbit the star.

The star is located fairly close to the [[Solar System]]: according to [[astrometric]] measurements made by the [[Gaia (spacecraft)|Gaia space observatory]], it exhibits a [[parallax]] of 72.0070 [[milliarcsecond]]s, corresponding to a distance of 45.30 light-years.<ref name="GaiaDR3"/> With an [[apparent magnitude]] of +5.03, it is visible to the [[naked eye]] and its [[absolute magnitude]] of +4.29 implies a visual [[luminosity]] around 60% greater than the Sun. A [[solar analog]], with a [[spectral type]] of G1V, it has a similar [[mass]] to that of the [[Sun]] but is slightly hotter at around 5,882 [[Kelvin|K]].<ref name="cne_stars"/> and slightly more [[metal-rich]] with around 110% of the solar [[Abundance of the chemical elements|abundance]] of [[iron]].

Like the Sun, 47 Ursae Majoris is on the [[main sequence]], converting [[hydrogen]] to [[helium]] in its core by [[nuclear fusion]]. Based on its [[chromospheric activity]], the star may be around six billion years old, though [[stellar evolution|evolutionary models]] suggest an older age of around 8.7 billion years.<ref name="saffe05"/> Other studies have yielded estimates of 4.4 and 7 billion years for the star.<ref name="apj687">
{{cite journal
 | author=E. E. Mamajek
 | author2=L. A. Hillenbrand|author2-link= Lynne Hillenbrand
 | date=2008
 | title=Improved Age Estimation for Solar-Type Dwarfs Using Activity-Rotation Diagnostics
 | journal=[[Astrophysical Journal]]
 | volume=687 | issue=2 | pages=1264–1293
 | bibcode=2008ApJ...687.1264M
 | doi=10.1086/591785
 | arxiv=0807.1686 | s2cid=27151456
 }}</ref> The low level of [[magnetic activity]] makes it a [[Maunder Minimum]] candidate star.<ref name=Lubin_et_al_2012/>

== Nomenclature ==
47 Ursae Majoris is the [[Flamsteed designation]]. On their discoveries the planets were successively designated 47 Ursau Majoris b, c and d.

In July 2014 the [[International Astronomical Union]] launched [[NameExoWorlds]], a process for giving proper names to certain exoplanets and their host stars.<ref>[http://www.iau.org/news/pressreleases/detail/iau1404/ NameExoWorlds: An IAU Worldwide Contest to Name Exoplanets and their Host Stars]. IAU.org. 9 July 2014</ref> The process involved public nomination and voting for the new names.<ref>{{Cite web |url=http://nameexoworlds.iau.org/process |title=NameExoWorlds The Process |access-date=2015-09-05 |archive-date=2015-08-15 |archive-url=https://web.archive.org/web/20150815025117/http://www.nameexoworlds.iau.org/process |url-status=dead }}</ref> In December 2015, the IAU announced the winning names were Chalawan for this star and Taphao Thong and Taphao Kaew for two of the planets (b and c, respectively).<ref>[http://www.iau.org/news/pressreleases/detail/iau1514/ Final Results of NameExoWorlds Public Vote Released], International Astronomical Union, 15 December 2015.</ref>
The winning names were submitted by the Thai Astronomical Society, [[Thailand]]. Chalawan ({{langx|th|ชาละวัน}} {{IPA|th|t͡ɕʰāːlāwān|}}) is a [[myth]]ological crocodile king from the Thai folktale [[Krai Thong]] and Taphaothong and Taphaokaeo are two sisters associated with the tale.<ref>{{Cite web |url=http://nameexoworlds.iau.org/names |title=NameExoWorlds The Approved Names |access-date=2015-12-19 |archive-date=2018-02-01 |archive-url=https://web.archive.org/web/20180201043609/http://nameexoworlds.iau.org/names |url-status=dead }}</ref> ('[[Chalawan (reptile)|Chalawan]]' is also the name given to an [[extinct]] [[genus]] of crocodylian. It contains a single species, ''Chalawan thailandicus''.<ref name=Chalawan>{{Cite journal | display-authors = 2 | last1 = Martin | first1 = J. E. | last2 = Lauprasert | first2 = K. | last3 = Buffetaut | first3 = E. | last4 = Liard | first4 = R. | last5 = Suteethorn | first5 = V. | editor1-last = Angielczyk | editor1-first = Kenneth | title = A large pholidosaurid in the Phu Kradung Formation of north-eastern Thailand | doi = 10.1111/pala.12086 | journal = Palaeontology | pages = 757–769| date = 2013 | volume=57| issue = 4 | s2cid = 128482290 | doi-access = free }}</ref>)

In 2016, the IAU organized a [[IAU Working Group on Star Names|Working Group on Star Names]] (WGSN)<ref name="WGSN">{{cite web | url=https://www.iau.org/science/scientific_bodies/working_groups/280/ | title=IAU Working Group on Star Names (WGSN)|access-date=22 May 2016}}</ref> to catalog and standardize proper names for stars. In its first bulletin of July 2016,<ref name="WGSN1">{{cite web | url=http://www.pas.rochester.edu/~emamajek/WGSN/WGSN_bulletin1.pdf | title=Bulletin of the IAU Working Group on Star Names, No. 1 |access-date=28 July 2016}}</ref> the WGSN explicitly recognized the names of exoplanets and their host stars approved by the Executive Committee Working Group Public Naming of Planets and Planetary Satellites, including the names of stars adopted during the 2015 NameExoWorlds campaign. This star is now so entered in the IAU Catalog of Star Names.<ref name="IAU-CSN"/>

== Planetary system ==
In 1996 an [[exoplanet]] ([[47 UMa b]]) was announced in orbit around 47 Ursae Majoris by [[Geoffrey Marcy]] and [[R. Paul Butler]]. The discovery was made by observing the [[Doppler shift]] of the star's [[stellar spectrum|spectrum]] corresponding to changes in the star's [[radial velocity]] as the planet's [[gravity]] pulled it around.<ref>
{{cite journal
 | author=R. P. Butler
 | title=A Planet Orbiting 47 Ursae Majoris
 | journal=[[Astrophysical Journal Letters]]
 | volume=464 | issue=2 | date=1996
 | pages=L153–L156
 | doi=10.1086/310102
| bibcode=1996ApJ...464L.153B
 | last2=Marcy
 | first2=Geoffrey W.
| doi-access=free
 }}</ref> The planet was the first [[orbital period|long-period]] extrasolar planet discovered. Unlike the majority of known such planets, it has a [[Orbital eccentricity|low-eccentricity]] orbit. The planet is at least 2.53 times the mass of [[Jupiter]] and takes 1,078 days, or 2.95 years, to orbit its star. If it were to be located in the Solar System, it would lie between the orbits of [[Mars]] and Jupiter.<ref name="bayesian">
{{cite journal
 |author=P. C. Gregory
 |author2=D. A. Fischer
 |date=2010
 |title=A Bayesian periodogram finds evidence for three planets in 47 Ursae Majoris
 |journal=[[Monthly Notices of the Royal Astronomical Society]]
 |volume=403 |issue=2 |pages=731–747
 |doi=10.1111/j.1365-2966.2009.16233.x
|doi-access=free
 |bibcode=2010MNRAS.403..731G
|arxiv = 1003.5549 |s2cid=16722873
 }}</ref>

[[File:47UMaOrbits.svg|thumb|left|Orbits of the planets in the 47 Ursae Majoris system. The orbit of [[47 UMa d]] is currently quite uncertain; both it and that of [[47 UMa c]] may be circular.]]

In 2001, preliminary astrometric measurements made by the [[Hipparcos]] probe suggested the orbit of 47 UMa b is [[Orbital inclination|inclined]] at an angle of 63.1° to the plane of the sky, implying the planet's [[true mass]] is around 2.9 times that of Jupiter.<ref>
{{cite journal
 | display-authors=2
 | author=I. Han
 | author2=D. C. Black
 | author3=G. Gatewood
 | date=2001
 | title=Preliminary Astrometric Masses for Proposed Extrasolar Planetary Companions
 | journal=[[Astrophysical Journal Letters]]
 | volume=548 | issue=1 | pages=L57–L60
 | doi=10.1086/318927
| bibcode=2001ApJ...548L..57H
| doi-access=free
 }}</ref> However, subsequent analysis suggested the Hipparcos measurements were not precise enough to accurately determine the orbits of substellar companions, and the inclination and true mass remain unknown.<ref>
{{cite journal
 |author=D. Pourbaix
 |author2=F. Arenou
 |date=2001
 |title=Screening the Hipparcos-based astrometric orbits of sub-stellar objects
 |journal=[[Astronomy and Astrophysics]]
 |volume=372 |pages=935–944
 |bibcode=2001A&A...372..935P
 |doi=10.1051/0004-6361:20010597
 |arxiv = astro-ph/0104412
 |issue=3 |s2cid=378792
 }}</ref>

A second planet ([[47 UMa c]]) was announced in 2002 by [[Debra Fischer]], Geoffrey Marcy and R. Paul Butler. The discovery was made using the same [[radial velocity]] method. According to Fischer et al., the planet takes around 2,391 days, or 6.55 years, to complete an orbit. This configuration is similar to the configuration of Jupiter and [[Saturn]] in the Solar System, with the orbital ratio (close to 5:2) and mass ratio roughly similar.<ref name="fischer">
{{cite journal
 | author=D. A. Fischer
 | date=2002
 | title=A Second Planet Orbiting 47 Ursae Majoris
 | journal=[[Astrophysical Journal]]
 | volume=564 | issue=2 | pages=1028–1034
 | doi=10.1086/324336
| bibcode=2002ApJ...564.1028F
 | last2=Marcy
 | first2=Geoffrey W.
 | last3=Butler
 | first3=R. Paul
 | last4=Laughlin
 | first4=Gregory
 | last5=Vogt
 | first5=Steven S.
| display-authors=2
 | citeseerx=10.1.1.8.9343
 | s2cid=18090715
 }}</ref> Subsequent measurements failed to confirm the existence of the second planet, and it was noted that the dataset used to determine its existence left the planet's parameters "almost unconstrained".<ref>{{cite journal
| journal=[[Astronomy and Astrophysics]]
| title=The ELODIE survey for northern extra-solar planets. III. Three planetary candidates detected with ELODIE
| url=http://www.aanda.org/index.php?option=article&access=standard&Itemid=129&url=/articles/aa/pdf/2004/04/aa0091.pdf
| volume=414
| issue=1
| pages=351–359
| year=2004
| doi=10.1051/0004-6361:20034091
| last1=Naef |first1=Dominique
| last2=Mayor |first2=Michel
| last3=Beuzit |first3=Jean-Luc
| last4=Perrier |first4=Christian
| last5=Queloz |first5=Didier
| last6=Sivan |first6=Jean-Pierre
| last7=Udry |first7=Stéphane
| bibcode=2004A&A...414..351N
|arxiv = astro-ph/0310261 | s2cid=16603563
}}</ref> Analysis of a longer dataset spanning over 6,900 days suggests that while a second planet in the system is likely, periods near 2,500 days have a high false-alarm probability,{{why|date=November 2014}} and the best fit model gives an orbital period of 7,586 days at a distance of 7.73 [[Astronomical unit|AU]] from the star. Nevertheless, the parameters of the second planet are still highly uncertain.<ref name="wittenmyer">
{{cite journal
 |display-authors=2
 |author=R. A. Wittenmyer
 |author2=M. Endl
 |author3=W. D.Cochran
 |date=2007
 |title=Long-Period Objects in the Extrasolar Planetary Systems 47 Ursae Majoris and 14 Herculis
 |journal=[[Astrophysical Journal]]
 |volume=654 |issue=1 |pages=625–632
 |bibcode=2007ApJ...654..625W
 |doi=10.1086/509110
|arxiv = astro-ph/0609117 |s2cid=14707902
 }}</ref> On the other hand, the Catalog of Nearby Exoplanets gives a period of 2,190 days, which would put the planets close to a 2:1 ratio of orbital periods, though the reference for these parameters is uncertain: the original Fischer ''et al.'' paper is cited as a reference in spite of the fact that it gives different parameters,<ref name="fischer"/><ref name="cne">
{{cite web
 |title=Planets Table
 |url=http://exoplanets.org/planets.shtml
 |work=Catalog of Nearby Exoplanets
 |access-date=2008-10-04
| archive-url= https://web.archive.org/web/20080921002236/http://exoplanets.org/planets.shtml| archive-date= 21 September 2008 | url-status= live}}</ref> though this solution has been adopted by the ''[[Extrasolar Planets Encyclopaedia]]''.<ref name=EPE47Umac>
{{cite encyclopedia
 |url=https://exoplanet.eu/catalog/47_uma_c--72/
 |title=Notes for Planet 47 Uma c
 |author=Jean Schneider
 |date=2011
 |encyclopedia=[[Extrasolar Planets Encyclopaedia]]
 |access-date=3 October 2011
}}</ref>

In 2010, the discovery of a third planet ([[47 UMa d]]) was made by using the [[Bayesian Kepler Periodogram]]. Using this model of this planetary system it was determined that it is 100,000 times more likely to have three planets than two planets. This discovery was announced by Debra Fischer and P. C. Gregory. This {{Jupiter mass|1.64}} planet has an orbital period of 14,002 days, or 38.33 years, and a semi-major axis of 11.6 AU with a moderate eccentricity of 0.16.<ref name="bayesian"/> It would be the longest-period planet discovered by the radial velocity method, although longer-period planets had previously been discovered by [[direct imaging]] and [[pulsar timing]].

Simulations suggest that the inner part of the [[habitable zone]] of 47 Ursae Majoris could host a [[terrestrial planet]] in a stable orbit, though the outer regions of the habitable zone would be disrupted by the gravitational influence of the planet 47 UMa b.<ref>
{{cite journal
 |author=B. Jones
 |date=2005
 |title=Prospects for Habitable "Earths" in Known Exoplanetary Systems
 |journal=[[Astrophysical Journal]]
 |volume=622 |issue=2 |pages=1091–1101
 |bibcode=2005ApJ...622.1091J
 |doi=10.1086/428108
|arxiv = astro-ph/0503178
 |last2=Underwood
 |first2=David R.
 |last3=Sleep
 |first3=P. Nick |s2cid=119089227
 |display-authors=2
 }}</ref> However, the presence of a giant planet within 2.5 AU of the star may have disrupted planet formation in the inner system, and reduced the amount of water delivered to inner planets during [[Accretion (astrophysics)|accretion]].<ref>
{{cite journal
 | author=S. Raymond
 | date=2006
 | title=The Search for other Earths: limits on the giant planet orbits that allow habitable terrestrial planets to form
 | journal=[[Astrophysical Journal Letters]]
 | volume=643 | issue=2 | pages=L131–134
 | doi=10.1086/505596
 | arxiv=astro-ph/0605136
| bibcode=2006ApJ...643L.131R
| s2cid=14298813
 }}</ref> This may mean any terrestrial planets orbiting in the habitable zone of 47 Ursae Majoris are likely to be small and dry. {{As of|2008}}, there have been two [[Active SETI|METI]] messages sent to 47 Ursae Majoris. Both were transmitted from [[Eurasia]]'s largest [[radar]]—{{convert|70|m|adj=mid}} [[Yevpatoria RT-70 radio telescope|Eupatoria Planetary Radar]]. The first message, the [[Teen Age Message]], was sent on September 3, 2001, and it will arrive at 47 Ursae Majoris in July 2047. The second message, [[Cosmic Call 2]], was sent on July 6, 2003, and it will arrive at 47 Ursau Majoris in May 2049.<ref>{{cite web
 |author=А. Л. Зайцев
 |date=7 June 2004
 |script-title=ru:Передача и поиски разумных сигналов во Вселенной
 |url=http://www.cplire.ru/rus/ra%26sr/VAK-2004.html
 |work=Пленарный доклад на Всероссийской астрономической конференции ВАК-2004 "Горизонты Вселенной", Москва, МГУ
 |language=ru
 |access-date=5 February 2008
 |archive-date=30 May 2019
 |archive-url=https://web.archive.org/web/20190530145209/https://www.plover.com/misc/Dumas-Dutil/messages.pdf
 |url-status=dead
 }}</ref>

{{OrbitboxPlanet begin
|table_ref = <ref name="bayesian"/>
}}
{{OrbitboxPlanet
| exoplanet = [[47 Ursae Majoris b|b (Taphao Thong)]]
| mass = >2.53{{±|0.07|0.06}}
| period = 1,078 ± 2
| semimajor = 2.10 ± 0.02
| eccentricity = 0.032 ± 0.014
}}
{{OrbitboxPlanet
| exoplanet = [[47 Ursae Majoris c|c (Taphao Kaew)]]
| mass = >0.540{{±|0.066|0.073}}
| period = 2,391{{±|100|70}}
| semimajor = 3.6 ± 0.1
| eccentricity = 0.098{{±|0.047|0.096}}
}}
{{OrbitboxPlanet
| exoplanet = [[47 Ursae Majoris d|d]]
| mass = >1.64{{±|0.29|0.48}}
| period = 14,002{{±|4,018|5,095}}
| semimajor = 11.6{{±|2.1|2.9}}
| eccentricity = 0.16{{±|0.09|0.16}}
}}
{{Orbitbox end}}

Because of its planetary system, 47 Ursae Majoris was listed as one of the top 100 target stars for [[NASA]]'s former [[Terrestrial Planet Finder]] mission.<ref>
{{Cite web |date=2006-08-19 |title=TPF-C Top 100 {{!}} #72 HIP 53721 |url=http://sco.stsci.edu/tpf_top100/detail.php?starchoice=53721 |access-date=2024-12-31 |archive-url=https://web.archive.org/web/20060819080212/http://sco.stsci.edu/tpf_top100/detail.php?starchoice=53721 |archive-date=19 August 2006 }}</ref>

== See also ==
* [[Disrupted planet]]
* [[14 Herculis]]
* [[51 Pegasi]]
* [[70 Virginis]]
* [[Lists of exoplanets]]

== Notes ==
{{reflist|group=note|refs=
{{#tag:ref|From <math>\begin{smallmatrix}L=4 \pi R^2 \sigma T_{\rm eff}^4 \end{smallmatrix}</math>, where <math>\begin{smallmatrix}L \end{smallmatrix}</math> is the luminosity, <math>\begin{smallmatrix}R \end{smallmatrix}</math> is the radius, <math>\begin{smallmatrix}T_{\rm eff}\end{smallmatrix}</math> is the effective surface temperature and <math>\begin{smallmatrix}\sigma \end{smallmatrix}</math> is the [[Stefan–Boltzmann constant]].|group="note"|name=bolometric_luminosity}}
}}

== References ==
{{reflist|refs=

<ref name=aaa343_222>{{citation | display-authors=2 | last1=Elgarøy | first1=Øystein | last2=Engvold | first2=Oddbjørn | last3=Lund | first3=Niels | title=The Wilson-Bappu effect of the MgII K line - dependence on stellar temperature, activity and metallicity | journal=Astronomy and Astrophysics | volume=343 | pages=222–228 | bibcode=1999A&A...343..222E |date=March 1999}}</ref>

<ref name="GaiaDR3">{{Cite Gaia DR3|777254360337133312}}</ref>

<ref name=Lubin_et_al_2012>{{cite journal
 | last1=Lubin | first1=Dan | last2=Tytler | first2=David
 | last3=Kirkman | first3=David | display-authors=1
 | title=Frequency of Maunder Minimum Events in Solar-type Stars Inferred from Activity and Metallicity Observations
 | journal=The Astrophysical Journal Letters
 | volume=747 | issue=2 | page=L32 | date=March 2012
 | doi=10.1088/2041-8205/747/2/L32 | doi-access=free
 | bibcode=2012ApJ...747L..32L }}</ref>

}}

== External links ==
*{{cite web
 |title=47 Ursae Majoris
 |url=http://www.solstation.com/stars2/47uma.htm
 |access-date=2008-06-26
 |work=SolStation
| archive-url= https://web.archive.org/web/20080511142234/http://www.solstation.com/stars2/47uma.htm| archive-date= 2008-05-11| url-status= live
}}
*{{cite web
 |title=47 Ursae Majoris 
 |url=http://exoplanets.org/detail/47_UMa
 |access-date=2013-10-05
 |work=Exoplanet Data Explorer
 }}
{{47 Ursae Majoris}}

{{Stars of Ursa Major}}
{{Sky|10|59|28.0|+|40|25|49|45.9}}
<!-- Properties -->

[[Category:47 Ursae Majoris| ]]
[[Category:G-type main-sequence stars]]
[[Category:Solar analogs|Ursae Majoris, 47]]
[[Category:Maunder Minimum]]
[[Category:Planetary systems with three confirmed planets]]
<!-- Other -->
[[Category:Ursa Major]]
[[Category:Durchmusterung objects|BD+41 2147]]
[[Category:Flamsteed objects|Ursae Majoris, 47]]
[[Category:Gliese and GJ objects|0407]]
[[Category:Henry Draper Catalogue objects|095128]]
[[Category:Hipparcos objects|053721]]
[[Category:Bright Star Catalogue objects|4277]]
[[Category:Stars with proper names|Chalawan]]