View source for Astronomy:2MASS J05325346+8246465

{{Short description|Star in the constellation Camelopardalis}}
{{Sky|05|32|53.46|+|82|46|46.5|87.0}}
{{Starbox begin
|name=2MASS J05325346+8246465
}}
{{Starbox observe
|epoch=[[Astronomy:J2000|J2000]]<ref name="Simbad"/>
|equinox=[[Astronomy:J2000|J2000]]<ref name="Simbad"/>
|constell=[[Astronomy:Camelopardalis|Camelopardalis]]
|ra={{RA|05|32|53.46}}<ref name="Simbad"/>
|dec={{DEC|+82|46|46.5}}<ref name="Simbad"/>
}}
{{Starbox character
|class=L7<ref name="Simbad"/>
}}
{{Starbox astrometry
|parallax=40.2369
|p_error=0.6389
|parallax_footnote={{r|Simbad}}
}}
{{Starbox detail
|age_gyr=~10<ref name=Zhang2019/>
|mass=0.077–0.085<ref>{{Cite journal|url=https://iopscience.iop.org/article/10.1086/375813/fulltext/57859.text.html|doi = 10.1086/375813|title = The First Substellar Subdwarf? Discovery of a Metal‐poor L Dwarf with Halo Kinematics|year = 2003|last1 = Burgasser|first1 = Adam J.|last2 = Kirkpatrick|first2 = J. Davy|last3 = Burrows|first3 = Adam|last4 = Liebert|first4 = James|last5 = Reid|first5 = I. Neill|last6 = Gizis|first6 = John E.|last7 = McGovern|first7 = Mark R.|last8 = Prato|first8 = L.|last9 = McLean|first9 = Ian S.|journal = The Astrophysical Journal|volume = 592|issue = 2|pages = 1186–1192|arxiv = astro-ph/0304174|bibcode = 2003ApJ...592.1186B|s2cid = 11895472}}</ref>
|temperature=1600<ref name=Zhang2019/>
|metal_fe=-1.6<ref name=Zhang2019>{{citation|arxiv=1903.05536|year=2019|title=Primeval very low-mass stars and brown dwarfs – VI. Population properties of metal-poor degenerate brown dwarfs|doi=10.1093/mnras/stz777|last1=Allard|first1=F.|last2=Pinfield|first2=D. J.|last3=Zapatero Osorio|first3=M. R.|last4=Lodieu|first4=N.|last5=Gálvez-Ortiz|first5=M. C.|last6=Burgasser|first6=A. J.|last7=Zhang (张曾华)|first7=Z. H.|journal=Monthly Notices of the Royal Astronomical Society|volume=486|pages=1260–1282}}</ref>
}}
{{Starbox catalog
|names=2MASS J05325346+8246465,<ref name="Simbad"/><br>2MASS 0532+8246
}}
{{Starbox reference
|Simbad=2MASS+J05325346%2B8246465
}}
{{Starbox end}}

'''2MASS J05325346+8246465''' (abbreviated '''2MASS J0532+8246''') is possibly the first [[Astronomy:Brown dwarf|brown dwarf]] observed in the [[Astronomy:Galactic halo|galactic halo]] of the Milky Way, and the first known substellar [[Astronomy:Subdwarf|subdwarf]] star.<ref name="Faherty2012" /><ref name="Burgasser2003" /> It was discovered from Two Micron All-Sky Survey data, and verified by observations at [[Organization:Palomar Observatory|Palomar Observatory]] and [[Astronomy:W. M. Keck Observatory|W. M. Keck Observatory]].<ref name="Burgasser2003" /> It has a low [[Astronomy:Metallicity|metallicity]], which indicates it is an old star.<ref name="Burgasser2003" />

The mass and temperature of 2MASS 0532+8246 makes it a rare object in stellar-substellar gap between conventional stars and brown dwarfs.<ref>{{citation|arxiv=1702.02001|title=Primeval very low-mass stars and brown dwarfs – II. The most metal-poor substellar object|year=2017|doi=10.1093/mnras/stx350|last1=Zhang 张曾华|first1=Z. H.|last2=Homeier|first2=D.|last3=Pinfield|first3=D. J.|last4=Lodieu|first4=N.|last5=Jones|first5=H. R. A.|last6=Allard|first6=F.|last7=Pavlenko|first7=Ya. V.|journal=Monthly Notices of the Royal Astronomical Society|volume=468|issue=1 |pages=261–271|bibcode=2017MNRAS.468..261Z |s2cid=54847595}}</ref> It produces roughly half of its luminosity from hydrogen fusion.<ref name=Zhang2019/> Such "gap" objects, covering a narrow range of masses but a wide range of temperatures, and powered by unsteady hydrogen fusion, are exotic but expected to be more common among low-metallicity objects like 2MASS J05325346+8246465.<ref>{{citation|arxiv=2007.03836|year=2020|title=WISEA J041451.67–585456.7 and WISEA J181006.18–101000.5: The First Extreme T-type Subdwarfs?|doi=10.3847/1538-4357/ab9a40|last1=Schneider|first1=Adam C.|last2=Burgasser|first2=Adam J.|last3=Gerasimov|first3=Roman|last4=Marocco|first4=Federico|last5=Gagné|first5=Jonathan|last6=Goodman|first6=Sam|last7=Beaulieu|first7=Paul|last8=Pendrill|first8=William|last9=Rothermich|first9=Austin|last10=Sainio|first10=Arttu|last11=Kuchner|first11=Marc J.|last12=Caselden|first12=Dan|last13=Meisner|first13=Aaron M.|last14=Faherty|first14=Jacqueline K.|last15=Mamajek|first15=Eric E.|last16=Hsu|first16=Chih-Chun|last17=Greco|first17=Jennifer J.|last18=Cushing|first18=Michael C.|last19=Kirkpatrick|first19=J. Davy|last20=Bardalez-Gagliuffi|first20=Daniella|last21=Logsdon|first21=Sarah E.|last22=Allers|first22=Katelyn|last23=Debes|first23=John H.|author24=The Backyard Worlds|author25=Planet 9 Collaboration|journal=The Astrophysical Journal|volume=898|issue=1|page=77|bibcode=2020ApJ...898...77S|s2cid=220403370 |doi-access=free }}</ref>

==References==
{{Reflist|colwidth=30em|refs=
<ref name="Burgasser2003">{{cite journal|author=Burgasser, Adam J.|display-authors=0|year=2003|title=The First Substellar Subdwarf? Discovery of a Metal-Poor L Dwarf with Halo Kinematics.|journal=The Astrophysical Journal|volume=592|issue=2|pages=1186–1192|doi=10.1086/375813|arxiv=astro-ph/0304174|bibcode=2003ApJ...592.1186B|s2cid=11895472}}</ref>
<ref name="Simbad">{{cite web
 | url=http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=2MASS+J05325346%2B8246465&submit=SIMBAD+search
 | title=2MASS J05325346+8246465 -- Brown Dwarf (M<0.08solMass)
 | work=[[Astronomy:SIMBAD|SIMBAD]]
 | publisher=Centre de Données astronomiques de Strasbourg
 | accessdate=2018-12-04}}</ref>
<ref name="Faherty2012">
{{cite journal  |last=Faherty |first=Jacqueline K.  |author2=Burgasser, Adam J. |author3=Walter, Frederick M. |author4=Van der Bliek, Nicole |author5=Shara, Michael M. |author6=Cruz, Kelle L. |author7=West, Andrew A. |author8=Vrba, Frederick J. |author9=Anglada-Escud, Guillem  |title=The Brown Dwarf Kinematics Project (BDKP). III. Parallaxes for 70 Ultracool Dwarfs  |year=2012  |journal=[[Astronomy:The Astrophysical Journal|The Astrophysical Journal]]  |volume=752 | issue=1 | pages=56  |arxiv=1203.5543  |doi=10.1088/0004-637X/752/1/56  |bibcode=2012ApJ...752...56F|s2cid=18160586 }}</ref>
}}

==External links==
*[http://ldwarf.ipac.caltech.edu/archive/version5/viewlist.php?table=ltdwarf&format=html Entry at DwarfArchives.org] {{Webarchive|url=https://web.archive.org/web/20190610082016/http://ldwarf.ipac.caltech.edu/archive/version5/viewlist.php?table=ltdwarf&format=html |date=2019-06-10 }}

<!--dist_ly = (32.616&nbsp;– 97.8)
dist_pc= (~10–30) (Burgasser, et al. 2003)?-->

{{Stars of Camelopardalis}}

{{DEFAULTSORT:2MASS J05325346+8246465}}
[[Category:Brown dwarfs]]
[[Category:2MASS objects|J05325346+8246465]]


{{Sourceattribution|2MASS J05325346+8246465}}