HD 21447
{{Short description|Probable binary star in the constellation Camelopardalis}}
{{Starbox begin
| name = HD 21447
}}
{{Starbox observe
| epoch = J2000
| constell = Camelopardalis
| dec = {{DEC|+55|27|06.5158}}
}}
{{Starbox character
| type =
| variable =
}}
{{Starbox astrometry
| parallax = 16.42
| p_error = 0.29
}}
{{Starbox detail
| source =
| temperature = {{Val|10049|342|fmt=commas}}
| metal_fe =
}}
{{Starbox catalog
| names = {{odlist | BD=+54°684 | HD=21447 | HIP=16292 | HR=1046 | SAO=24064 | WDS=J03300+5527A | NSV=1159 }}
}}
{{Starbox reference
| Simbad = HD+21447
}}
{{Starbox end}}
HD 21447 is a probable binary star system located in the constellation Camelopardalis. The star is also known as HR 1046. It can be viewed with the naked eye, having an apparent visual magnitude of 5.09. Based upon an annual parallax shift of {{Val|16.42|0.29|ul=mas}}, it is located some 199 light years from the Sun. It is a candidate for membership in the Ursa Major Moving Group.
The primary component is A-type main-sequence star with a stellar classification of A1 Va. It is around 146 million years old and is spinning with a projected rotational velocity of 182 km/s. The star has an estimated 2.32 times the mass of the Sun and about 1.9 times the Sun's radius. It is radiating around 32 times the Sun's luminosity from its photosphere at an effective temperature of 10,049 K. The companion is visual magnitude 9.4 star at an angular separation of {{Val|14.8|ul=arcsec}}.
References
{{reflist|refs=
{{cite simbad | title=HD 21447 | access-date=2018-05-16 }}
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| arxiv=0708.1752 | bibcode=2007A&A...474..653V
| doi=10.1051/0004-6361:20078357 | s2cid=18759600 }}
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| bibcode=2012AstL...38..331A | doi=10.1134/S1063773712050015
| arxiv=1108.4971 | s2cid=119257644 | postscript=. }}
{{citation | display-authors=1
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| title=Stellar Kinematic Groups. II. A Reexamination of the Membership, Activity, and Age of the Ursa Major Group
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| bibcode=2003AJ....125.1980K | doi=10.1086/368241 | url=https://tigerprints.clemson.edu/cgi/viewcontent.cgi?article=1248&context=physastro_pubs | doi-access=free }}
| 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
| postscript=. | arxiv=0806.2878 | s2cid=14878976 }}
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| 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=. }}
| display-authors=1
| last1=De Rosa | first1=R. J. | last2=Patience | first2=J.
| last3=Wilson | first3=P. A. | last4=Schneider | first4=A.
| last5=Wiktorowicz | first5=S. J. | last6=Vigan | first6=A.
| last7=Marois | first7=C. | last8=Song | first8=I.
| last9=Macintosh | first9=B. | last10=Graham | first10=J. R.
| last11=Doyon | first11=R. | last12=Bessell | first12=M. S.
| last13=Thomas | first13=S. | last14=Lai | first14=O.
| title=The VAST Survey - III. The multiplicity of A-type stars within 75 pc
| journal=Monthly Notices of the Royal Astronomical Society
| volume=437 | issue=2 | pages=1216–1240 | date=January 2014
| doi=10.1093/mnras/stt1932 | doi-access=free | bibcode=2014MNRAS.437.1216D
| arxiv=1311.7141 | s2cid=88503488 | postscript=. }}
| title=The Early A-Type Stars: Refined MK Classification, Confrontation with Stroemgren Photometry, and the Effects of Rotation
| last1=Gray | first1=R. O. | last2=Garrison | first2=R. F.
| journal=Astrophysical Journal Supplement
| volume=65 | page=581 | date=December 1987
| doi=10.1086/191237 | bibcode=1987ApJS...65..581G | doi-access=free }}
| 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
| last1=David | first1=Trevor J. | last2=Hillenbrand | first2=Lynne A.
| bibcode=2015ApJ...804..146D | doi=10.1088/0004-637X/804/2/146
| arxiv=1501.03154 | s2cid=33401607
| postscript=. }}
}}
External links
- http://www.alcyone.de/cgi-bin/search.pl?object=HR1046 {{Webarchive|url=https://web.archive.org/web/20111117064231/http://www.alcyone.de/cgi-bin/search.pl?object=HR1046 |date=2011-11-17 }}
- http://server3.wikisky.org/starview?object_type=1&object_id=1996
{{Stars of Camelopardalis}}
{{DEFAULTSORT:HD 21447}}
Category:A-type main-sequence stars