View source for Beta Trianguli

{{short description|Binary star in the constellation Triangulum}}
{{Starbox begin
| name     = β Trianguli
}}
{{Starbox image
 | image=
{{Location mark
|image=Triangulum constellation map.svg|alt=|float=center|width=280
|label=|position=right
|mark=Red circle.svg|mark_width=12|mark_link=β Trianguli
|x=517|y=319
}}
|caption=Location of β Trianguli (circled)
}}
{{Starbox observe
| epoch    = [[J2000.0]]
| constell = [[Triangulum]]
| ra       = {{RA|02|09|32.62712}}<ref name=aaa474_2_653/>
| dec      = {{DEC|+34|59|14.2694}}<ref name=aaa474_2_653/>
| appmag_v = +3.00<ref name=clpl4_99/> (3.44 + 4.19)<ref name=Piccotti2020/>
}}
{{Starbox character
| class    = A8III / A3III<ref name=Piccotti2020/>
| b-v      = +0.21 / 0.07<ref name=Piccotti2020/>
| u-b      = +0.11<ref name=clpl4_99/>
| variable =
}}
{{Starbox astrometry
| radial_v = +9.9<ref name=gcrv1953/>
| prop_mo_ra = 149.16<ref name=aaa474_2_653/>
| prop_mo_dec = –39.10<ref name=aaa474_2_653/>
| parallax = 23.169
| p_error  = 0.434
| parallax_footnote = <ref name=Groenewegen2023/>
| absmag_v = {{Val|-0.136}} (0.305 + 0.1055)<ref name=Piccotti2020/>
}}
{{Starbox orbit
| reference = <ref name=Pourbaix2004>{{citation | display-authors=1 | last1=Pourbaix | first1=D. | last2=Tokovinin | first2=A. A. | last3=Batten | first3=A. H. | last4=Fekel | first4=F. C. | last5=Hartkopf | first5=W. I. | last6=Levato | first6=H. | last7=Morrell | first7=N. I. | last8=Torres | first8=G. | last9=Udry | first9=S. | year=2004 | pages=727–732 | volume=424 | title=SB9: The Ninth Catalogue of Spectroscopic Binary Orbits | journal=Astronomy & Astrophysics | issue=2 | bibcode=2004A&A...424..727P | doi=10.1051/0004-6361:20041213 | postscript=. | arxiv=astro-ph/0406573 | s2cid=119387088 }}</ref>
| period_unitless = 31.3884&nbsp;d
| eccentricity = 0.53
| axis_unitless = {{val|0.330|0.005}}<ref name=Piccotti2020/>
| periastron = 2432004.255&nbsp;JD
| periarg = 318.4
| k1 = 33.3
| k2 = 69.2
}}
{{Starbox detail
| source       = <ref name=Piccotti2020/>
| component1   = A
| mass         = {{val|2.6|0.3}}
| radius       = {{solar radius calculator|type=logLT|1.78|7683|decimals=2}}{{efn|name=radius1}}
| luminosity   = {{val|60.3|15.6|12.4}}
| temperature  = 7,683
| gravity      = 3.70<ref name=gray>{{Cite journal | last1 = Gray | first1 = R. O. | last2 = Corbally | first2 = C. J. | last3 = Garrison | first3 = R. F. | last4 = McFadden | first4 = M. T. | last5 = Robinson | first5 = P. E. | title = Contributions to the Nearby Stars (NStars) Project: Spectroscopy of Stars Earlier than M0 within 40 Parsecs: The Northern Sample. I | doi = 10.1086/378365 | journal = The Astronomical Journal | volume = 126 | issue = 4 | pages = 2048 | year = 2003 |arxiv = astro-ph/0308182 |bibcode = 2003AJ....126.2048G | s2cid = 119417105 }}</ref>
| metal_fe     =
| rotational_velocity = 70<ref name=aaa393_897/>
| age_gyr      = {{val|0.40|0.23|0.15}}
| component2   = B
| mass2        = {{val|2.25|0.05}}
| radius2      = {{solar radius calculator|type=logLT|1.50|8759|decimals=2}}{{efn|name=radius2}}
| luminosity2  = {{val|31.6|3.9|3.4}}
| temperature2 = 8,759
| age_gyr2     = {{val|0.45|0.12|0.09}}
}}
{{Starbox catalog
| names = β&nbsp;Trianguli, β&nbsp;Tri, Beta&nbsp;Tri, 4&nbsp;Trianguli, [[Star catalogue#BS, BSC, HR|HR]]&nbsp;622, [[Henry Draper Catalogue|HD]]&nbsp;13161, [[Bonner Durchmusterung|BD]]+34°381, FK5&nbsp;75, [[Hipparcos catalogue|HIP]]&nbsp;10064, [[Star catalogue#SAO|SAO]]&nbsp;55306.<ref name=SIMBAD/>
}}
{{Starbox reference
| Simbad = bet+Tri
}}
{{Starbox end}}

'''Beta&nbsp;Trianguli''' ('''Beta&nbsp;Tri''', '''β&nbsp;Trianguli''', '''β&nbsp;Tri''') is the [[Bayer designation]] for a [[binary star]]<ref name=mnras389_2_869/> system in the [[constellation]] [[Triangulum]], located about 127 [[light years]] from [[Earth]].<ref name=aaa474_2_653/> Although it is only a third-magnitude star,<ref name=clpl4_99/> it is the brightest [[star]] in the [[constellation]] [[Triangulum]].<ref name=garfinckle1997/>

This is a double-lined [[spectroscopic binary]] star system with an orbital period of 31.39 days and an [[Orbital eccentricity|eccentricity]] of 0.53.<ref name=Pourbaix2004/> The members are separated by a distance of {{val|0.33|ul=AU}}. The primary and secondary components have [[stellar classification|stellar classifications]] of A8III and A3III respectively, indicating that they [[stellar evolution|evolved]] away from the [[main sequence]] and are now [[giant star]]s. Component A is 2.6 times more massive than the Sun, but expanded to {{solar radius calculator|type=logLT|1.78|7683|decimals=1}} the Sun's radius{{efn|name=radius1}} and irradiates 60 times more than the Sun. Component B is somewhat smaller and less luminous, being 2.25 times more massive, {{solar radius calculator|type=logLT|1.50|8759|decimals=2}} times larger{{efn|name=radius2}} and 30 times brighter than the Sun. The system has an age around 400 million years, less than 10% that of the [[Solar System]].<ref name=Piccotti2020/> Beta Trianguli is among the least [[variable star|variable]] of the stars that were observed by the [[Hipparcos]] spacecraft, with a magnitude varying by only 0.0005.<ref name=aaa367_297/>

Based on observations using the [[Spitzer Space Telescope]], as reported in 2005, this system is emitting an [[infrared excess|excess of infrared radiation]]. This emission can be explained by a circumbinary [[debris disk|ring of dust]]. The dust is emitting infrared radiation at a blackbody temperature of 100&nbsp;K.<ref name=pap5/> It is thought to extend from 50 to 400 AU away from the stars.<ref name=kennedy>{{cite journal|author1=Kennedy, G. M. |author2=Wyatt, M. C. |author3=Sibthorpe, B. |author4=Phillips, N. M. |author5=Matthews, B. |author6=Greaves, J. S. |date=2012|title=Coplanar Circumbinary Debris Disks|journal=[[Monthly Notices of the Royal Astronomical Society]]|volume=426|issue=3|pages=2115–28|bibcode=2012MNRAS.426.2115K|doi=10.1111/j.1365-2966.2012.21865.x|doi-access=free |arxiv = 1208.1759 |s2cid=59408005 }}</ref>

==Naming==
*In combination with [[Alpha Trianguli]], these stars were called Al Mīzān, which is [[Arabic language|Arabic]] for "The Scale Beam".<ref name=garfinckle1997/>
*In [[Chinese astronomy|Chinese]], {{lang|zh|天大將軍}} ({{lang|zh-Latn|Tiān Dà Jiāng Jūn}}), meaning ''[[Bond (Chinese constellation)|Heaven's Great General]]'', refers to an asterism consisting of β Trianguli, [[Gamma Andromedae|γ Andromedae]], [[Phi Persei|φ Persei]], [[51 Andromedae]], [[49 Andromedae]], [[Chi Andromedae|χ Andromedae]], [[Upsilon Andromedae|υ Andromedae]], [[Tau Andromedae|τ Andromedae]], [[56 Andromedae]], [[Gamma Trianguli|γ Trianguli]] and [[Delta Trianguli|δ Trianguli]]. Consequently, the [[Chinese star names|Chinese name]] for β Trianguli itself is {{lang|zh|天大將軍九}} ({{lang|zh-Latn|Tiān Dà Jiāng Jūn jiǔ}}, {{langx|en|the Ninth Star of Heaven's Great General}}.).<ref>{{in lang|zh}} [http://aeea.nmns.edu.tw/2006/0607/ap060710.html AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 10 日] {{Webarchive|url=https://web.archive.org/web/20110716123113/http://aeea.nmns.edu.tw/2006/0607/ap060710.html |date=2011-07-16 }}</ref>

==See also==
* [[Beta Trianguli Australis]]
* [[Alpheratz]]
* [[Sheratan]]
* [[Menkalinan]]

==Notes==
{{notelist|notes=

{{Efn|name=radius1|1=Calculated, using the [[Stefan-Boltzmann law]] and the star's [[effective temperature]] and luminosity, with respect to the [[Sun|solar]] nominal effective temperature of 5,772&nbsp;[[Kelvin|K]]:<math display="block">\sqrt{\biggl(\frac{5,772}{7,683}\biggr)^4 \cdot 10^{1.78}} = 4.38\ R_\odot.</math>}}

{{Efn|name=radius2|1=Calculated, using the [[Stefan-Boltzmann law]] and the star's [[effective temperature]] and luminosity, with respect to the [[Sun|solar]] nominal effective temperature of 5,772&nbsp;[[Kelvin|K]]:<math display="block">\sqrt{\biggl(\frac{5,772}{8,759}\biggr)^4 \cdot 10^{1.50}} = 2.44\ R_\odot.</math>}}

}}

==References==
{{Reflist|30em|refs=

<ref name=Piccotti2020>{{Citation |last1=Piccotti |first1=Luca |last2=Docobo |first2=José Ángel |last3=Carini |first3=Roberta |last4=Tamazian |first4=Vakhtang S. |last5=Brocato |first5=Enzo |last6=Andrade |first6=Manuel |last7=Campo |first7=Pedro P. |date=2020-02-01 |title=A study of the physical properties of SB2s with both the visual and spectroscopic orbits |bibcode=2020MNRAS.492.2709P |journal=Monthly Notices of the Royal Astronomical Society |volume=492 |issue=2 |pages=2709–2721 |doi=10.1093/mnras/stz3616 |doi-access=free |issn=0035-8711}} [https://vizier.cds.unistra.fr/viz-bin/VizieR?-source=J/MNRAS/492/2709&HD=13161 Beta Trianguli's database entry] at [[VizieR]].</ref>

<ref name=Groenewegen2023>{{Citation |last=Groenewegen |first=M. A. T. |date=2023-01-01 |title=Orbital parallax of binary systems compared to Gaia DR3 and the parallax zero-point offset at bright magnitudes |arxiv=2210.14734 |journal=Astronomy and Astrophysics |volume=669 |pages=A4 |doi=10.1051/0004-6361/202244479 |bibcode=2023A&A...669A...4G|issn=0004-6361}} [https://vizier.cds.unistra.fr/viz-bin/VizieR?-source=J/A%2BA/669/A4&Name=02095%2B3459 Beta Trianguli's database entry].</ref>

<ref name=aaa474_2_653>{{citation | first=F. | last=van Leeuwen |date=November 2007 | title=Validation of the new Hipparcos reduction | journal=Astronomy and Astrophysics | volume=474 | issue=2 | pages=653–664 | bibcode=2007A&A...474..653V | doi=10.1051/0004-6361:20078357 |arxiv = 0708.1752 | s2cid=18759600 }}</ref>

<ref name=gcrv1953>{{citation | last=Wilson | first=Ralph Elmer | year=1953 | title=General catalogue of stellar radial velocities | journal=Washington | publisher=[[Carnegie Institution of Washington]] | bibcode=1953GCRV..C......0W }}</ref>

<ref name=aaa393_897>{{citation | display-authors=1 | last1=Royer | first1=F. | last2=Grenier | first2=S. | last3=Baylac | first3=M.-O. | last4=Gómez | first4=A. E. | last5=Zorec | first5=J. | title=Rotational velocities of A-type stars in the northern hemisphere. II. Measurement of v sin i | journal=Astronomy and Astrophysics | volume=393 | issue=3 | pages=897–911 |date=October 2002 | doi=10.1051/0004-6361:20020943 | bibcode=2002A&A...393..897R |arxiv = astro-ph/0205255 | s2cid=14070763 }}</ref>

<ref name=clpl4_99>{{citation | display-authors=1 | last1=Johnson | first1=H. L. | last2=Iriarte | first2=B. | last3=Mitchell | first3=R. I. | last4=Wisniewskj | first4=W. Z. | title=UBVRIJKL photometry of the bright stars | journal=Communications of the Lunar and Planetary Laboratory | volume=4 | issue=99 | pages=99 | year=1966 | bibcode=1966CoLPL...4...99J }}</ref>

<ref name=mnras389_2_869>{{citation | last1=Eggleton | first1=P. P. | last2=Tokovinin | first2=A. A. | title=A catalogue of multiplicity among bright stellar systems | journal=Monthly Notices of the Royal Astronomical Society | volume=389 | issue=2 | pages=869–879 |date=September 2008 | doi=10.1111/j.1365-2966.2008.13596.x | doi-access=free | bibcode=2008MNRAS.389..869E |arxiv = 0806.2878 | s2cid=14878976 }}</ref>

<ref name=garfinckle1997>{{citation | first1=Robert A. | last1=Garfinkle | title=Star-Hopping: Your Visa to Viewing the Universe | publisher=[[Cambridge University Press]] | year=1997 | isbn=0-521-59889-3 | page=238 | url=https://books.google.com/books?id=40JzBYGREL0C&pg=PA238 }}</ref>

<ref name=SIMBAD>{{citation | title=bet Tri -- Spectroscopic binary | work=SIMBAD | publisher=[[Centre de Données astronomiques de Strasbourg]] | url=http://simbad.u-strasbg.fr/simbad/sim-id?Ident=Beta+Trianguli | access-date=2011-12-12 }}</ref>

<ref name=aaa367_297>{{citation | last1=Adelman | first1=S. J. | title=Research Note Hipparcos photometry: The least variable stars | journal=Astronomy and Astrophysics | volume=367 | pages=297–298 |date=February 2001 | issue=1 | doi=10.1051/0004-6361:20000567 | bibcode=2001A&A...367..297A | doi-access=free }}</ref>

<ref name=pap5>{{cite conference | display-authors=1 | last1=Stansberry | first1=J. A. | last2=Stapelfeldt | first2=K. R. | last3=Trilling | first3=D. T. | last4=Su | first4=K. Y. | last5=Rieke | first5=G. H. | last6=Chen | first6=C. | contribution=A Spitzer Survey for Debris Disks in Binary Star Systems | title=Protostars and Planets V, Proceedings of the Conference held October 24-28, 2005, in Hilton Waikoloa Village, Hawai'i | pages=8613 | year=2005 | bibcode=2005prpl.conf.8613S }}</ref>

}}

{{Stars of Triangulum}}

{{DEFAULTSORT:Beta Trianguli}}
[[Category:Bayer objects|Trianguli, Beta]]
[[Category:Flamsteed objects|Trianguli, 04]]
[[Category:Triangulum]]
[[Category:Bright Star Catalogue objects|0622]]
[[Category:Henry Draper Catalogue objects|013161]]
[[Category:Hipparcos objects|010064]]
[[Category:Durchmusterung objects|BD+34 381]]
[[Category:A-type subgiants]]
[[Category:Spectroscopic binaries]]