beta Pyxidis
{{Short description|Double star in the constellation Pyxis}}
{{Starbox begin}}
{{Starbox image
| image =
{{Location mark
| image=Pyxis IAU.svg
| float=center | width=250 | position=right
| mark=Red circle.svg | mark_width=10 | mark_link=β Pyx
| x%=57.2 | y%=65.8
}}
| caption=Location of β Pyxidis (circled)
}}
{{Starbox observe
| epoch = J2000
| constell = Pyxis
}}
{{Starbox character
| variable =
}}
{{Starbox astrometry
| prop_mo_ra = {{nowrap|+9.84}}
| prop_mo_dec = {{nowrap|–20.80}}
| parallax = 7.84
| p_error = 0.19
| absmag_v = {{val|-1.196|0.093}}
}}
{{Starbox detail
| age_gyr =
| metal_fe = {{val|-0.06|0.053}}
| mass = {{val|3.77|0.18}}
| radius = {{val|20|1}}
| luminosity = {{val|283|25}}
| temperature ={{Val|5283|59|fmt=commas}}
| gravity = {{Val|2.68|0.09}}
}}
{{Starbox catalog
| names = {{odlist | B=β Pyx, Beta Pyx | CPD=−34 2846 | FK5=2681 | HD=74006 | HIP=42515 | HR=3438 | SAO=199490 | WDS=J08401-3518A }}
}}
{{Starbox reference
|Simbad=bet+Pyx
}}
{{Starbox end}}
Beta Pyxidis, Latinized from β Pyxidis, is a double star located in the southern constellation Pyxis. It has an apparent visual magnitude of 3.954, making it the second brightest star in that faint constellation. Based upon parallax measurements, the star is an estimated 420 light-years (128 parsecs) from the Earth.
The spectrum matches a bright giant or giant star of stellar classification G7II-III. It has 3.8 times the mass of the Sun but has expanded to 20 times the Sun's radius. The effective temperature of the star's outer envelope is about 5,283 K, giving it the characteristic yellow hue of a G-type star. Beta Pyxidis has an unusually high rate of spin for an evolved star of this type, showing a projected rotational velocity of 11.8 km/s. One possible explanation is that it may have engulfed a nearby giant planet, such as a hot Jupiter.
In 2010, the star was among a survey of massive, lower effective temperature supergiants in an attempt to detect a magnetic field. This star may have a longitudinal magnetic field with a strength of less than a Gauss. It is a young disk star system with space velocity components, {{nowrap|[U, V, W]}} = {{nowrap|[–11.0, +11.8, –2.2] km/s}}. There is a magnitude 12.5 optical companion, located at an angular separation of 12.7 arcseconds and a position angle of 118° as of the year 1943.
Naming
In Chinese, {{lang|zh|天狗}} ({{lang|zh-Latn|Tiān Gǒu}}), meaning Celestial Dog, refers to an asterism consisting of β Pyxidis, e Velorum, f Velorum, α Pyxidis, γ Pyxidis and δ Pyxidis. Consequently, β Pyxidis itself is known as {{lang|zh|天狗四}} ({{lang|zh-Latn|Tiān Gǒu sì}}, {{langx|en|the Fourth Star of Celestial Dog}}.){{in lang|zh}} [http://aeea.nmns.edu.tw/2006/0607/ap060717.html AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 17 日] {{Webarchive|url=https://web.archive.org/web/20120204114243/http://aeea.nmns.edu.tw/2006/0607/ap060717.html |date=2012-02-04 }}
References
{{reflist|30em|refs=
{{Cite journal |last1=Ottoni |first1=G. |last2=Udry |first2=S. |last3=Ségransan |first3=D. |last4=Buldgen |first4=G. |last5=Lovis |first5=C. |last6=Eggenberger |first6=P. |last7=Pezzotti |first7=C. |last8=Adibekyan |first8=V. |last9=Marmier |first9=M. |last10=Mayor |first10=M. |last11=Santos |first11=N. C. |last12=Sousa |first12=S. G. |last13=Lagarde |first13=N. |last14=Charbonnel |first14=C. |date=2022-01-01 |title=CORALIE radial-velocity search for companions around evolved stars (CASCADES). I. Sample definition and first results: Three new planets orbiting giant stars |bibcode=2022A&A...657A..87O |journal=Astronomy and Astrophysics |volume=657 |pages=A87 |doi=10.1051/0004-6361/202040078 |issn=0004-6361|arxiv=2201.01528 }} [https://vizier.cds.unistra.fr/viz-bin/VizieR?-source=J/A+A/657/A87&HD=74006 Beta Pyxidis' database entry] at VizieR.
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| volume=3 | date=1979 | postscript=.
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| bibcode=1982mcts.book.....H }}
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| journal=The Astrophysical Journal
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| doi=10.1088/0004-637X/801/1/54 | bibcode=2015ApJ...801...54R | arxiv=1503.03447| s2cid=119271718 }}
| title=bet Pyx | access-date=2021-07-29 | postscript=. }}
{{citation | display-authors=1 | last1=Grunhut | first1=J. H. | last2=Wade | first2=G. A. | last3=Hanes | first3=D. A. | last4=Alecian | first4=E. | title=Systematic detection of magnetic fields in massive, late-type supergiants | journal=Monthly Notices of the Royal Astronomical Society | volume=408 | issue=4 | pages=2290–2297 |date=November 2010 | doi=10.1111/j.1365-2966.2010.17275.x | doi-access=free | bibcode=2010MNRAS.408.2290G |arxiv = 1006.5891 | s2cid=118564860 }}
{{citation |title=The Colour of Stars |date=December 21, 2004 |work=Australia Telescope, Outreach and Education |publisher=Commonwealth Scientific and Industrial Research Organisation |url=http://outreach.atnf.csiro.au/education/senior/astrophysics/photometry_colour.html |access-date=2012-01-16 |url-status=dead |archive-url=https://web.archive.org/web/20120318151427/http://outreach.atnf.csiro.au/education/senior/astrophysics/photometry_colour.html |archive-date=2012-03-18 }}
}}
{{Stars of Pyxis}}
{{DEFAULTSORT:Beta Pyxidis}}