Beta Trianguli Australis
{{short description|Star in the constellation Triangulum Australe}}
{{Starbox begin}}
{{Starbox image
| image =
{{Location mark
| image=Triangulum Australe IAU.svg
| float=center | width=250 | position=right
| mark=Red circle.svg | mark_width=10 | mark_link=β TrA
| x%=51.0 | y%=40.6
}}
| caption=Location of β Trianguli Australis (circled)
}}
{{Starbox observe
| epoch = J2000
| dec = {{DEC|−63|25|50.6155}}
| constell = Triangulum Australe
}}
{{Starbox character
| variable =
}}
{{Starbox astrometry
| parallax = 80.79
| p_error = 0.16
}}
{{Starbox detail
| radius = {{val|1.976|0.021}}
| luminosity = {{val|9.30|0.17}}
| temperature = {{Val|7171|35|fmt=commas}}
| gravity = {{Val|4.219|0.066}}
| metal_fe = {{val|−0.29|0.10}}
| rotational_velocity = 69.63
| rotation =
}}
{{Starbox catalog
| names = {{odlist | B=β TrA | CD=−63°1135 | FK5=589 | GJ=601 | HD=141891 | HIP=77952 | HR=5897 | LTT=6339 | SAO=253346 }}
}}
{{Starbox reference
| Simbad = bet+TrA
}}
{{Starbox end}}
Beta Trianguli Australis, Latinized from β Trianguli Australis, is a star in the southern constellation of Triangulum Australe. It has an apparent visual magnitude of +2.85, making it the second-brightest star in the constellation. It is approximately {{Convert|40.37|ly|pc|abbr=off|lk=on}} from Earth and has an apparent visual magnitude of +2.85. This star has a relatively high rate of proper motion across the celestial sphere.
Characteristics
It is a F-type main-sequence star with a stellar classification of F1 V. It has 1.61 times the Sun's mass and 1.98 times the Sun's radius. It radiates 9.3 times the Sun's luminosity from its photosphere at an effective temperature of {{Val|7170|fmt=commas|u=K}}. The abundance of elements heavier than hydrogen and helium, what astronomers term metallicity, is somewhat lower than that of the Sun.
Observation with the Spitzer Space Telescope reveals what appears to be an excess infrared emission from this star. This suggests the presence of circumstellar material in this system, making it a debris disk candidate. This star may be a member of the Beta Pictoris moving group, an association of about 17 stars that share a common origin and a similar motion through space. If it is a member of this group, this would put the age of β TrA at about 12 million years; the same as the group itself.
β TrA has a nearby visual companion, the magnitude 13.2 star LTT 6333. However, it is actually a background object, with a distance of 900 light-years.{{cite simbad|title=LTT 6333}} This star is part of the Anateus moving group, which likely has an extragalactic origin.
Modern legacy
β TrA appears on the flag of Brazil, symbolising the state of Santa Catarina.
References
{{reflist|refs=
| title=Precision angular diameters for 16 southern stars with VLTI/PIONIER
| display-authors=1 | last1=Rains | first1=Adam D.
| last2=Ireland | first2=Michael J. | last3=White | first3=Timothy R.
| last4=Casagrande | first4=Luca | last5=Karovicova | first5=I.
| journal=Monthly Notices of the Royal Astronomical Society
| volume=493 | issue=2 | pages=2377–2394 | date=April 2020
| arxiv=2004.02343 | bibcode=2020MNRAS.493.2377R
| doi=10.1093/mnras/staa282 | doi-access=free }}
{{citation | display-authors=1 | last1=Gray | first1=R. O. | last2=Corbally | first2=C. J. | last3=Garrison | first3=R. F. | last4=McFadden | first4=M. T. | last5=Bubar | first5=E. J. | last6=McGahee | first6=C. E. | last7=O'Donoghue | first7=A. A. | last8=Knox | first8=E. R. | title=Contributions to the Nearby Stars (NStars) Project: spectroscopy of stars earlier than M0 within 40 pc-The Southern Sample | journal=The Astronomical Journal | volume=132 | issue=1 | pages=161–170 |date=July 2006 | doi=10.1086/504637 | bibcode=2006AJ....132..161G | arxiv=astro-ph/0603770 | s2cid=119476992 }}
{{citation | last=Evans | first=D. S. | date=June 20–24, 1966 | editor1-last=Batten | editor1-first=Alan Henry | editor2-last=Heard | editor2-first=John Frederick | contribution=The Revision of the General Catalogue of Radial Velocities | volume=30 | page=57 | title=Determination of Radial Velocities and their Applications, Proceedings from IAU Symposium no. 30 | location=University of Toronto | publisher=International Astronomical Union | bibcode=1967IAUS...30...57E }}
{{citation | title=LTT 6339 -- High proper-motion Star | work=SIMBAD | publisher=Centre de Données astronomiques de Strasbourg | url=http://simbad.u-strasbg.fr/simbad/sim-id?Ident=Beta+Trianguli+Australis | access-date=2012-01-28 }}
| last1=David | first1=Trevor J. | last2=Hillenbrand | first2=Lynne A.
| title=The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets
| journal=The Astrophysical Journal
| volume=804 | issue=2 | pages=146 | year=2015
| bibcode=2015ApJ...804..146D | doi=10.1088/0004-637X/804/2/146
| arxiv=1501.03154 | s2cid=33401607 | postscript=. }}
| title=XHIP: An extended hipparcos compilation
| last1=Anderson | first1=E. | last2=Francis | first2=Ch.
| journal=Astronomy Letters
| volume=38 | issue=5 | pages=331 | year=2012
| bibcode=2012AstL...38..331A | doi=10.1134/S1063773712050015
| arxiv=1108.4971 | s2cid=119257644 | postscript=. }}
}}
{{Stars of Triangulum Australe}}
{{DEFAULTSORT:Beta Trianguli Australis}}
Category:F-type main-sequence stars
Category:Beta Pictoris moving group