delta Pyxidis
{{Short description|Binary star system in the constellation Pyxis}}
{{Starbox begin
| name = Delta Pyxidis
}}
{{Starbox image
| image =
{{Location mark
| image=Pyxis IAU.svg | alt= | float=center | width=250
| label= | position=right
| mark=Red circle.svg | mark_width=10 | mark_link=δ Pyx
| x=495 | y=425
}}
| caption=Location of δ Pyxidis (circled)
}}
{{Starbox observe
| epoch = J2000.0
| constell = Pyxis
| dec = {{DEC|−27|40|54.7315}}
}}
{{Starbox character
| variable =
}}
{{Starbox astrometry
| parallax = 13.19
| p_error = 0.77
}}
{{Starbox detail
| source =
| temperature = {{Val|8609|293|fmt=commas}}
| metal_fe =
}}
{{Starbox catalog
| names = {{odlist | B=δ Pyx | FK5=| CPD=−27° 3497 | HD=76483 | HIP=43825 | HR=3556 | SAO=176697 | WDS=J08555-2741A }}
}}
{{Starbox reference
| Simbad = del+Pyx
}}
{{Starbox end}}
Delta Pyxidis (δ Pyxidis) is binary star system in southern constellation of Pyxis. Having an apparent visual magnitude of +4.877, it is bright enough to be visible to the naked eye. Based upon an annual parallax shift of 13.19 mas as seen from Earth, it is located around 250 light years from the Sun.
In Chinese, {{lang|zh|天狗}} ({{lang|zh-Latn|Tiān Gǒu}}), meaning Celestial Dog, refers to an asterism consisting of δ Pyxidis, e Velorum, f Velorum, β Pyxidis, α Pyxidis and γ Pyxidis. Consequently, δ Pyxidis itself is known as {{lang|zh|天狗七}} ({{lang|zh-Latn|Tiān Gǒu qī}}, {{langx|en|the Seventh 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 }}
This is an astrometric binary system, as determined by changes in the proper motion of the primary. The visible component has a stellar classification of A3 IV, indicating it has the spectrum of an A-type subgiant star that is consuming the last of the hydrogen at its core. At the age of around 296 million years, it is 92.5% of the way through its main sequence lifetime and is spinning with a projected rotational velocity of 68 km/s. The star has an estimated 1.8 times the mass of the Sun and about 1.6 times the Sun's radius. It is radiating 59 times the Sun's luminosity from its photosphere at an effective temperature of roughly 8,609 K.
References
{{reflist|refs=
| title=Validation of the new Hipparcos reduction
| last1=van Leeuwen | first1=F.
| journal=Astronomy and Astrophysics
| volume=474 | issue=2 | pages=653–664 | date=2007
| arxiv=0708.1752 | bibcode=2007A&A...474..653V
| doi=10.1051/0004-6361:20078357 | s2cid=18759600 | 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=. }}
| display-authors=1 | last1=Gutierrez-Moreno | first1=Adelina
| last2=Moreno | first2=H. | last3=Stock | first3=J.
| last4=Torres | first4=C. | last5=Wroblewski | first5=H.
| title=A System of photometric standards
| journal=Publications of the Department of Astronomy University of Chile | publisher=Publicaciones Universidad de Chile, Department de Astronomy
| volume=1 | pages=1–17 | year=1966
| bibcode=1966PDAUC...1....1G | postscript=. }}
| display-authors=1 | last1=Frankowski | first1=A.
| last2=Jancart | first2=S. | last3=Jorissen | first3=A.
| title=Proper-motion binaries in the Hipparcos catalogue. Comparison with radial velocity data
| journal=Astronomy and Astrophysics
| volume=464 | issue=1 | pages=377–392 |date=March 2007
| doi=10.1051/0004-6361:20065526 | bibcode=2007A&A...464..377F
| arxiv=astro-ph/0612449 | s2cid=14010423 | postscript=. }}
| last1=Pasinetti Fracassini | first1=L. E. | last2=Pastori | first2=L.
| last3=Covino | first3=S. | last4=Pozzi | first4=A.
| title=Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS)
| edition=3rd | journal=Astronomy and Astrophysics
| volume=367 | pages=521–524 | date=February 2001
| doi=10.1051/0004-6361:20000451 | bibcode=2001A&A...367..521P
| arxiv=astro-ph/0012289 | s2cid=425754 | postscript=. }}
| 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
| bibcode=2008MNRAS.389..869E | doi=10.1111/j.1365-2966.2008.13596.x
| doi-access=free | arxiv=0806.2878 | s2cid=14878976 | postscript=. }}
| last1=de Bruijne | first1=J. H. J. | last2=Eilers | first2=A.-C.
| title=Radial velocities for the HIPPARCOS-Gaia Hundred-Thousand-Proper-Motion project
| journal=Astronomy & Astrophysics
| volume=546 | id=A61 | pages=14 | date=October 2012
| doi=10.1051/0004-6361/201219219 | bibcode=2012A&A...546A..61D
| arxiv=1208.3048 | s2cid=59451347 | postscript=. }}
| last1=Zorec | first1=J. | last2=Royer | first2=F.
| title=Rotational velocities of A-type stars. IV. Evolution of rotational velocities
| journal=Astronomy & Astrophysics
| volume=537 | page=A120 | date=January 2012
| doi=10.1051/0004-6361/201117691 | bibcode=2012A&A...537A.120Z
| arxiv=1201.2052 | s2cid=55586789 | postscript=. }}
| 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=del Pyx | accessdate=2017-07-19 | postscript=. }}
}}
{{Stars of Pyxis|state=collapsed}}
{{DEFAULTSORT:Delta Pyxidis}}