2MASS J05325346+8246465

{{Starbox begin

| name = 2MASS J05325346+8246465

}}

{{Starbox image

| image = 250px

| caption = 2MASS J0532+8246

| credit = SDSS

}}

{{Starbox observe

| epoch = J2000

| constell = Camelopardalis

| ra = {{RA|05|32|54.4345}}

| dec = {{DEC|+82|46|45.161}}

}}

{{Starbox character

| class = esdL8:

}}

{{Starbox astrometry

| radial_v ={{val|-172|1}}

| prop_mo_ra = {{val|2038.794|(561)}}

| prop_mo_dec = {{val|−1662.958|(484)}}

| pm_footnote =

| parallax = 40.7097

| p_error = 0.4597

| parallax_footnote =

}}

{{Starbox detail

| age_gyr = ~10

| mass = 0.077–0.085{{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}}

| temperature = 1600

| metal_fe = −1.6{{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|doi-access=free }}

| rotational_velocity =65 ±15

}}

{{Starbox catalog

| names = 2MASS J05325346+8246465,
2MASS 0532+8246

}}

{{Starbox reference

| Simbad = 2MASS+J05325346%2B8246465

}}

2MASS J05325346+8246465 (abbreviated 2MASS J0532+8246) is possibly the first brown dwarf observed in the galactic halo of the Milky Way, and the first known substellar subdwarf star. It was discovered from Two Micron All-Sky Survey data, and verified by observations at Palomar Observatory and W. M. Keck Observatory. It has a low metallicity, which indicates it is an old star.

The mass and temperature of 2MASS 0532+8246 makes it a rare object in stellar-substellar gap between conventional stars and brown dwarfs.{{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|doi-access=free |bibcode=2017MNRAS.468..261Z |s2cid=54847595}} It produces roughly half of its luminosity from hydrogen fusion. 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.{{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.|journal=The Astrophysical Journal|volume=898|issue=1|page=77|bibcode=2020ApJ...898...77S|s2cid=220403370 |doi-access=free }}

In 2008 it was discovered that this object is on a retrograde galactic orbit that is both eccentric and extends well away from the plane, making this object a member of the galactic halo. In 2024 this object was identified as a possible member of the Thamnos populations, together with the T subdwarf CWISE J113010.07+313944.7. Thamnos has two substructures called Thamnos 1 and Thamnos 2, both were identified in 2019 from Gaia data. Thamnos is likely the remnant of a dwarf galaxy that was accreted into the Milky Way and consists of metal-poor stars that formed between 8 and 12.89 billion years.

References

{{Reflist|refs=

{{Cite journal |last=Reiners |first=A. |last2=Basri |first2=G. |date=2006-03-01 |title=The First High-Resolution Spectra of 1.3 L Subdwarfs |url=https://ui.adsabs.harvard.edu/abs/2006AJ....131.1806R/abstract |journal=The Astronomical Journal |volume=131 |pages=1806–1815 |arxiv=astro-ph/0512130 |bibcode=2006AJ....131.1806R |doi=10.1086/500298 |issn=0004-6256}}

{{Cite journal |last=Deepak |date=2024-12-01 |title=Stellar substructures in the Galactic disc and halo: Properties, origins, and evolution |url=https://ui.adsabs.harvard.edu/abs/2024JApA...45...25D/abstract |journal=Journal of Astrophysics and Astronomy |volume=45 |pages=25 |arxiv=2407.14508 |bibcode=2024JApA...45...25D |doi=10.1007/s12036-024-10011-1 |issn=0250-6335}}

{{Cite journal |last=Koppelman |first=Helmer H. |last2=Helmi |first2=Amina |last3=Massari |first3=Davide |last4=Price-Whelan |first4=Adrian M. |last5=Starkenburg |first5=Tjitske K. |date=2019-11-01 |title=Multiple retrograde substructures in the Galactic halo: A shattered view of Galactic history |url=https://ui.adsabs.harvard.edu/abs/2019A&A...631L...9K/abstract |journal=Astronomy and Astrophysics |volume=631 |pages=L9 |arxiv=1909.08924 |bibcode=2019A&A...631L...9K |doi=10.1051/0004-6361/201936738 |issn=0004-6361}}

{{Cite journal |last=Burgasser |first=Adam J. |last2=Vrba |first2=Frederick J. |last3=Lépine |first3=Sébastien |last4=Munn |first4=Jeffrey A. |last5=Luginbuhl |first5=Christian B. |last6=Henden |first6=Arne A. |last7=Guetter |first7=Harry H. |last8=Canzian |first8=Blaise C. |date=2008-01-01 |title=Parallax and Luminosity Measurements of an L Subdwarf |url=https://ui.adsabs.harvard.edu/abs/2008ApJ...672.1159B/abstract |journal=The Astrophysical Journal |volume=672 |pages=1159–1166 |arxiv=0709.1373 |bibcode=2008ApJ...672.1159B |doi=10.1086/523810 |issn=0004-637X}}

{{cite journal|author=Burgasser, Adam J.|display-authors=etal|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}}

{{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=SIMBAD

| publisher=Centre de Données astronomiques de Strasbourg

| accessdate=2018-12-04}}

{{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=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 }}

{{Cite arxiv |eprint=2411.01378 |class=

astro-ph |last=Burgasser |first=Adam J. |title=New Cold Subdwarf Discoveries from Backyard Worlds and a Metallicity Classification System for T Subdwarfs |date=2 Nov 2024 |last2=Schneider |first2=Adam C. |last3=Meisner |first3=Aaron M. |last4=Caselden |first4=Dan |last5=Hsu |first5=Chih-Chun |last6=Gerasimov |first6=Roman |last7=Aganze |first7=Christian |last8=Softich |first8=Emma |last9=Karpoor |first9=Preethi |first10=Christopher A. |last10=Theissen |first11=Hunter |last11=Brooks |first12=Thomas P. |last12=Bickle |first13=Jonathan |last13=Gagné |first14=Étienne |last14=Artigau |first15=Michaël |last15=Marsset |first16=Austin |last16=Rothermich |first17=Jacqueline K. |last17=Faherty |first18=J. Davy |last18=Kirkpatrick |first19=Marc J. |last19=Kuchner |first20=Nikolaj Stevnbak |last20=Andersen |first21=Paul |last21=Beaulieu |first22=Guillaume |last22=Colin |first23=Jean Marc |last23=Gantier |first24=Leopold |last24=Gramaize |first25=Les |last25=Hamlet |first26=Ken |last26=Hinckley |first27=Martin |last27=Kabatnik |first28=Frank |last28=Kiwy |first29=David W. |last29=Martin |first30=Diego H. |last30=Massat |first31=William |last31=Pendrill |first32=Arttu |last32=Sainio |first33=Jörg |last33=Schümann |first34=Melina |last34=Thévenot |first35=Jim |last35=Walla |first36=Zbigniew |last36=Wędracki |last37=the Backyard Worlds: Planet 9 Collaboration}}

}}

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 }}

Category:Camelopardalis

Category:Brown dwarfs

Category:L-type brown dwarfs

J05325346+8246465

Category:Free-floating substellar objects