HD 15920
{{short description|Giant star in the constellation Cassiopeia}}
{{Starbox begin}}
{{Starbox observe
| epoch = J2000.0
| constell = Cassiopeia
| dec = {{DEC|+72|49|05.7106}}
}}
{{Starbox character
| type =
| u-b =
| variable =
}}
{{Starbox astrometry
| radial_v = {{Val|−3.69|0.13}}
| parallax = 12.1723
| p_error = 0.1139
}}
{{Starbox detail
| radius = {{Val|10.06|0.15|0.17}}
| luminosity = {{Val|60.7|0.7}}
| temperature = {{Val|5080|37|42|fmt=commas}}
| metal_fe = {{Val|0.02|0.05}}
| rotational_velocity =
| age_myr = {{Val|977|198|164}}
}}
{{Starbox catalog
| names = {{odlist | BD=+72°140 | FK5=87 | HD=15920 | HIP=12273 | HR=743 | SAO=4694 | GC=3116 | GSC=04320-02109 }}
}}
{{Starbox reference
| Simbad = HD+15920
}}
{{Starbox end}}
HD 15920 is a single star in the northern constellation of Cassiopeia. It has a yellow hue and is visible to the naked eye as a dim point of light with an apparent visual magnitude of 5.17. This object is located at a distance of approximately 268 light years from the Sun based on parallax, but it is drifting closer with a radial velocity of −4 km/s.
This object is an aging giant star with a stellar classification of G8III. After exhausting the supply of hydrogen at its core, this star has cooled and expanded off the main sequence – at present it has ten times the girth of the Sun. The star is around a billion years old with 2.6 times the mass of the Sun. It is radiating 61 times the Sun's luminosity from its swollen photosphere at an effective temperature of 5,080 K. HD 15920 is the most likely source for the X-ray emission detected at these coordinates.
References
{{reflist|refs=
{{cite simbad | title=HD 15920 | access-date=2019-11-16}}
{{cite DR2|545900827338842752}}
| title=XHIP: An extended hipparcos compilation
| last1=Anderson | first1=E. | last2=Francis | first2=Ch.
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| volume=38 | issue=5 | pages=331 | year=2012
| bibcode=2012AstL...38..331A | doi=10.1134/S1063773712050015
| s2cid=119257644 | postscript=. }}
| title=Determining Ages of APOGEE Giants with Known Distances
| journal=The Astrophysical Journal
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| last2=Bovy | first2=Jo | last3=Holtzman | first3=Jon
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| volume=817 | pages=40 | year=2016
| issue=1
| bibcode=2016ApJ...817...40F | doi=10.3847/0004-637X/817/1/40
| arxiv=1511.04088 | s2cid=118675933
| postscript=. | 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
| arxiv=0806.2878 | s2cid=14878976 | postscript=. }}
| title=The Spectra of the Bright Stars of Types F5-K5
| last=Roman | first=Nancy G. | postscript=.
| journal=Astrophysical Journal
| volume=116 | page=122 | date=July 1952
| doi=10.1086/145598 | bibcode=1952ApJ...116..122R | doi-access=free }}
| last1=Haakonsen | first1=Christian Bernt | last2=Rutledge | first2=Robert E.
| title=XID II: Statistical Cross-Association of ROSAT Bright Source Catalog X-ray Sources with 2MASS Point Source Catalog Near-Infrared Sources
| journal=The Astrophysical Journal Supplement
| volume=184 | issue=1 | pages=138–151 | date=September 2009
| doi=10.1088/0067-0049/184/1/138 | postscript=.
| bibcode=2009ApJS..184..138H | arxiv=0910.3229 | s2cid=119267456 }}
}}
{{Stars of Cassiopeia}}
Category:Cassiopeia (constellation)