47 Ursae Majoris
1197737
224829068
2008-07-10T16:32:12Z
Kbdankbot
6505923
Robot - move category per [[WP:CFD|CFD]] [[Wikipedia:Categories for discussion/Log/2008 July 2|2008 July 2]]
{{Starbox begin
| name = 47 Ursae Majoris
}}
{{Starbox observe
| epoch = [[J2000.0]]
| constell = [[Ursa Major]]
| ra = {{RA|10|59|28.0}}
| dec = {{DEC|+40|25|49}}
| appmag_v = +5.03
}}
{{Starbox character
| class = G1V
| r-i =
| v-r =
| b-v = 0.61
| u-b = 0.13
| variable = ''None''
}}
{{Starbox astrometry
| radial_v = +12.6
| prop_mo_ra = –315.92
| prop_mo_dec = 55.15
| parallax = 71.04
| p_error = 0.66
| absmag_v = 4.29
}}
{{Starbox detail
| mass = 1.03
| radius = 1.26
| density = 725
| gravity = 4.04
| luminosity = 1.54
| temperature = 5,740
| metal = 110%
| rotation = ~3 km/s.(~21 days)
| age = 6.03 × 10<sup>9</sup>
}}
{{Starbox catalog
| names = [[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|Gl 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 = HD+95128
| ARICNS = <!--Code-->
}}
{{Starbox end}}
'''47 Ursae Majoris''', often abbreviated as '''47 UMa''', is a [[solar twin]], [[yellow dwarf]] [[star]] approximately 46 [[light-year]]s away in the [[constellation]] of [[Ursa Major]]. [[As of 2002]], it has been confirmed that two [[extrasolar planet]]s orbit the star. Because of this, 47 Ursae Majoris was listed as one of top 100 target stars for [[NASA]]'s former [[Terrestrial Planet Finder]] mission.<ref>{{cite web|url=http://sco.stsci.edu/tpf_top100/detail.php?starchoice=53721|title=#72 HIP 53721|work=TPF-C Top 100|accessmonthday=22 July|accessyear=2006}}</ref>
== Distance and visibility ==
47 Ursae Majoris is located fairly close to our [[solar system]]: according to [[astrometry|astrometric]] measurements made by the [[Hipparcos]] astrometry [[satellite]], the star exhibits a [[parallax]] of 71.04 [[milliarcsecond]]s, corresponding to a distance of 14.1 [[parsec]]s.<ref>{{cite web|url=http://vizier.u-strasbg.fr/viz-bin/VizieR-S?HIP%2053721|title=HIP 53721|work=The Hipparcos and Tycho Catalogues|publisher=ESA|year=1997|accessmonthday=22 July|accessyear=2006}}</ref> With an [[apparent magnitude]] of +5.03, it is visible to the [[naked eye]] under good conditions.
== Stellar components ==
47 Ursae Majoris has a similar [[mass]] to that of our Sun. It is slightly more [[metal-rich]] than the Sun, having around 110% of the solar [[Abundance of the chemical elements|abundance]] of [[iron]]. With a [[stellar classification|spectral type]] of G1V, it is also slightly hotter than the Sun, at around 5,855 [[Kelvin|K]].<ref name="cne">{{cite journal|doi= 10.1086/504701|author=Butler, R. et al.|title=Catalog of Nearby Exoplanets|journal=[[The Astrophysical Journal]]|volume=646|pages=505 – 522|year=2006}} ([http://exoplanets.org/planets.shtml web version])</ref> 47 Ursae Majoris has an [[absolute magnitude]] of +4.29, implying it has a visual [[luminosity]] around 60% greater than the Sun.
Like the Sun, 47 Ursae Majoris is on the [[main sequence]], converting [[hydrogen]] to [[helium]] in its core by [[nuclear fusion]]. Based on its [[chromosphere|chromospheric]] activity, the star may be around 6,000 million [[year]]s old, though [[stellar evolution|evolutionary models]] suggest an older age of around 8,700 million years.<ref>{{cite journal |url=http://cdsads.u-strasbg.fr/cgi-bin/nph-bib_query?2005A%26A...443..609S&db_key=AST&nosetcookie=1 |author=Saffe, C. et al.|title=On the Ages of Exoplanet Host Stars |journal=[[Astronomy and Astrophysics]]|volume=443|issue=2|pages=609 – 626|year=2005|doi=10.1051/0004-6361:20053452}}</ref>
== Planetary system ==
In 1996 an extrasolar planet was announced in orbit around 47 Ursae Majoris by [[Geoffrey Marcy]] and [[R. Paul Butler]]. The discovery was made by observing the change in the star's [[radial velocity]] as the planet's [[gravity]] pulled it around. The measurements were made by observing the [[Doppler shift]] of the star's [[spectrum]].<ref>{{cite journal | url=http://www.journals.uchicago.edu/doi/full/10.1086/310102|author=Butler, R. et al. | title=A Planet Orbiting 47 Ursae Majoris|journal=[[The Astrophysical Journal]] | volume=464 | issue=2 | year=1996 | pages=L153 – L156 | doi=10.1086/310102 <!--Retrieved from URL by DOI bot-->}}</ref> The planet, designated [[47 Ursae Majoris b]] was the first long-[[orbital period|period]] extrasolar planet discovered. Unlike the majority of known long-period extrasolar planets, 47 Ursae Majoris b has a low-[[eccentricity (orbit)|eccentricity]] orbit. The planet is at least 2.63 times the mass of [[Jupiter]] and takes 1,089 [[day]]s to orbit its star. If located in our solar system, it would lie between the orbits of [[Mars]] and Jupiter.<ref name="cne" />
[[Image:47UmaOrbits.svg|thumb|left|Orbits of the 47 Ursae Majoris system (black) compared with the planets of our solar system (blue).]]
In 2001, preliminary astrometric measurements made by the [[Hipparcos]] probe suggest the orbit of 47 Ursae Majoris b is [[inclination|inclined]] at an angle of 63.1° to the plane of the sky. If these measurements are confirmed, this implies the planet's [[true mass]] is around 2.9 times that of Jupiter.<ref>{{cite journal | url=http://www.journals.uchicago.edu/doi/full/10.1086/318927 | title=Preliminary Astrometric Masses for Proposed Extrasolar Planetary Companions | author=Han, I. et al. | journal=[[The Astrophysical Journal]] | volume=548 | issue=1 | pages=L57 – L60 | year=2001 | doi=10.1086/318927 <!--Retrieved from URL by DOI bot-->}}</ref> However, subsequent analysis suggests that the Hipparcos measurements are not precise enough to accurately determine the orbits of substellar companions, and the inclination and true mass remain unknown.<ref>{{cite journal|url=http://adsabs.harvard.edu/abs/2001A%26A...372..935P|title=Screening the Hipparcos-based astrometric orbits of sub-stellar objects|author=Pourbaix, D. and Arenou, F.|journal=[[Astronomy and Astrophysics]]|volume=372|pages=935 – 944|year=2001|doi=10.1051/0004-6361:20010597|format=abstract}}</ref>
A second planet, designated [[47 Ursae Majoris c]] was announced in 2002 by [[Debra Fischer]], Geoffrey Marcy and R. Paul Butler. The discovery was made using the same [[radial velocity]] method used to detect the first planet. According to Fischer et al., the planet takes around 2,594 days to complete an orbit. This configuration is similar to the configuration of Jupiter and Saturn in our solar system, with the orbital ratio (close to 5:2), and mass ratio roughly similar.<ref name="fischer">{{cite journal | url=http://www.journals.uchicago.edu/doi/full/10.1086/324336 | author=Fischer, D. et al. | title=A Second Planet Orbiting 47 Ursae Majoris | journal=The Astrophysical Journal | volume=564 | issue=2 | year=2002 | pages=1028 – 1034 | doi=10.1086/324336}}</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 |url=http://cdsads.u-strasbg.fr/cgi-bin/nph-bib_query?2004A%26A...414..351N&db_key=AST&nosetcookie=1 |author=Naef, D. et al.|title=The ELODIE survey for northern extra-solar planets. III. Three planetary candidates detected with ELODIE|journal=[[Astronomy and Astrophysics]]|volume=414|pages=351 – 359|year=2004|doi=10.1051/0004-6361:20034091}}</ref> Analysis of a longer dataset spanning over 6900 days suggests that while a second planet in the system is likely, periods near 2,500 days have a high false alarm probability, and the best fit model gives an orbital period of 7586 days at a distance of 7.73 AU from the star. Nevertheless, the parameters of the second planet are still highly uncertain.<ref name="wittenmyer">{{cite journal |url=http://cdsads.u-strasbg.fr/cgi-bin/nph-bib_query?2007ApJ...654..625W&db_key=AST&nosetcookie=1 |author=Wittenmyer, R. A., Endl, M., Cochran, W. D.|title=Long-Period Objects in the Extrasolar Planetary Systems 47 Ursae Majoris and 14 Herculis|journal=[[The Astrophysical Journal]]|volume=654|issue=1|pages=625 – 632|year=2007|doi=10.1086/509110}}</ref> However, the parameter of this planet is now confirmed, at an orbital distance of 3.39 ± 0.36 AU and a period of 2190 ± 460 days or 6 years.
Simulations suggest that the inner part of the [[habitable zone]] of 47 Ursae Majoris could host a terrestrial planet on a stable orbit, though the outer regions of the habitable zone would be disrupted by the gravitational influence of the planet 47 Ursae Majoris b.<ref>{{cite journal |url=http://cdsads.u-strasbg.fr/cgi-bin/nph-bib_query?2005ApJ...622.1091J&db_key=AST&nosetcookie=1 |author=Jones, B. et al.|title=Prospects for Habitable "Earths" in Known Exoplanetary Systems|journal=[[The Astrophysical Journal]]|volume=622|issue=2|pages=1091 – 1101|year=2005|doi=10.1086/428108}}</ref> However, the presence of a giant planet within 2.5 [[Astronomical unit|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 (science)|accretion]].<ref>{{cite journal|url=http://arxiv.org/abs/astro-ph/0605136|title=The Search for other Earths: limits on the giant planet orbits that allow habitable terrestrial planets to form|author=Raymond, S.|year=2006|journal=[[The Astrophysical Journal]] Letters (accepted)|volume=643|pages=L131|doi=10.1086/505596|format=abstract}}</ref> This may mean any [[terrestrial planet]]s orbiting in the habitable zone of 47 Ursae Majoris are likely to be small and dry. [[As of 2008]], there were two [[Message to Extra-Terrestrial Intelligence|METI]] messages sent to 47 Ursae Majoris. Both were transmitted from [[Eurasia]]'s largest [[radar]] — 70-meter [[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 Ursae Majoris in May 2049.<ref>{{ru icon}} http://www.cplire.ru/rus/ra&sr/VAK-2004.html</ref>
{{OrbitboxPlanet begin}}
{{OrbitboxPlanet
| exoplanet = [[47 Ursae Majoris b|b]]
| mass = >2.60 ± 0.13
| period = 1083.2 ± 1.8
| semimajor = 2.11 ± 0.04
| eccentricity = 0.049 ± 0.014
}}
{{OrbitboxPlanet
| exoplanet = [[47 Ursae Majoris c|c]]
| mass = >0.460
| period = 2190 ± 460
| semimajor = 3.39
| eccentricity = 0.220 ± 0.028
}}
{{Orbitbox end}}
== See also ==
*[[Stars and planetary systems in fiction#47 Ursae Majoris|47 Ursae Majoris in fiction]]
*[[51 Pegasi]]
*[[70 Virginis]]
*[[List of stars with confirmed extrasolar planets]]
== References ==
{{reflist}}
== External links ==
* {{cite web |url=http://www.extrasolar.net/startour.asp?StarCatId=normal&StarId=7 |title=47 Ursae Majoris |accessdate=2008-06-26 |work=Extrasolar Visions}}
* {{cite web |url=http://www.solstation.com/stars2/47uma.htm |title=47 Ursae Majoris |accessdate=2008-06-26 |work=SolStation}}
* {{cite web |url=http://exoplanet.eu/star.php?st=47+UMa |title=Notes for star 47 UMa |accessdate=2008-06-26 |work=The Extrasolar Planets Encyclopaedia}}
[[Category:Flamsteed objects|Ursae Majoris, 47]]
[[Category:HD and HDE objects|095128]]
[[Category:HIP objects|53721]]
[[Category:Multiple planetary systems|2, 47 Ursae Majoris]]
[[Category:Ursa Major constellation]]
[[Category:G-type main sequence stars]]
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