| 词条 | 2MASS J0523-1403 |
| 释义 |
| name=2MASS J0523-1403 }}{{Starbox observe | epoch = J2000 | constell = Lepus | ra = {{RA|05|23|38.221}}[1] | dec = {{DEC|-14|03|02.29}}[1] | appmag_v = 21.05[3] }}{{Starbox character | class = L2.5V[3] | b-v = | u-b = | v-k = 9.42[3] | variable = }}{{Starbox astrometry | radial_v = 12.21 ± 0.09[2] | prop_mo_ra = {{val|107.254|0.290}}[7] | prop_mo_dec = {{val|160.897|0.341}}[7] | parallax = 78.3632 | p_error = 0.1855 | parallax_footnote = [3] | absmag_v = 20.6[3] }}{{Starbox detail | mass_mj = {{val|67.54|12.79}}[4] | radius = | radius_rj = {{val|1.01|0.07}}[4] | luminosity = 0.000138[4] | temperature = {{val|1,939|68}}[4] | gravity = {{val|5.21|0.16}}[4] | metal_fe = | rotational_velocity = 21[5] | age_gyr = }}{{Starbox catalog | names = 2MASS J05233822-1403022, 2MUCD 10390, B2006 J052338.2-140302, 2MASSI J0523382-140302, USNO-B1.0 0759-00062850 }}{{Starbox reference | Simbad = 2MASS+J05233822-1403022 }}{{Starbox end}}2MASS J0523-1403 is a very-low-mass red dwarf about 40 light years from Earth in the southern constellation of Lepus. With a very faint visual magnitude of 21.05 and a low effective temperature of 2074 K it is visible primarily in large telescopes sensitive to infrared light. 2MASS J0523-1403 was first observed as part of the Two Micron All-Sky Survey (2MASS).[6] Characteristics2MASS J0523-1403 has a luminosity of {{Solar luminosity|link=y|0.000126}}, a radius of {{Solar radius|link=y|0.086}}, and an effective temperature of 2074 K. These values are currently the lowest known for a main sequence star.[7] It has a stellar classification of L2.5 and a V-K color index of 9.42.[7] The mass is calculated to be {{jupiter mass|{{val|67.54|12.79}}}} ({{solar mass|{{val|0.0644|0.0122}}}}).[4] Observation with the Hubble Space Telescope has detected no companion beyond 0.15 arcsecond.[8] Sporadic radio emissions were detected by the VLA in 2004.[9] H-alpha (Hα) emissions have also been detected, a sign of chromospheric activity.[5] Hydrogen burning limitMembers of the RECONS group have recently identified 2MASS J0523-1403 as representative of the smallest possible stars.[10] Its small radius is at the local minimums of the radius-luminosity and radius-temperature trends.[7] This local minimum is predicted to occur at the hydrogen burning limit due to differences in the radius-mass relationships of stars and brown dwarfs. Unlike stars, brown dwarfs decrease in radius as mass increases due to their cores being supported by degeneracy pressure. As the mass increases an increasing fraction of the brown dwarf is degenerate causing the radius to shrink as mass increases.[10] The minimum stellar mass is estimated to be between 0.07 and 0.077 {{Solar mass}}, comparable to the mass of 2MASS J0523-1403.[7]
References1. ^1 {{cite web|title=2MASS J05233822-1403022|url=http://simbad.u-strasbg.fr/simbad/sim-id?Name=2MASS%20J05233822-1403022&Ident=%40788130|publisher=SIMBAD - Centre de Données astronomiques de Strasbourg|accessdate=14 December 2013}} 2. ^{{cite journal|last=Blake|first=Cullen H.|last2=Charbonneau|first2=David|last3=White|first3=Russel J.|title=The NIRSPEC Ultracool Dwarf Radial Velocity Survey|journal=The Astrophysical Journal|date=2010|volume=723|issue=1|pages=684–706|doi=10.1088/0004-637X/723/1/684|arxiv=1008.3874|bibcode = 2010ApJ...723..684B }} 3. ^1 2 {{cite DR2|2985035874544160384}} 4. ^1 2 3 4 5 {{cite journal|doi=10.1088/0004-637X/810/2/158|title=Fundamental Parameters and Spectral Energy Distributions of Young and Field Age Objects with Masses Spanning the Stellar to Planetary Regime|journal=The Astrophysical Journal|volume=810|issue=2|pages=158|year=2015|last1=Filippazzo|first1=Joseph C.|last2=Rice|first2=Emily L.|last3=Faherty|first3=Jacqueline|last4=Cruz|first4=Kelle L.|last5=Van Gordon|first5=Mollie M.|last6=Looper|first6=Dagny L.}} 5. ^1 {{cite journal | last = Reiners | first = A. | last2 = Basri | first2 = G. | title = Chromospheric Activity, Rotation, and Rotational Braking in M and L Dwarfs | journal = The Astrophysical Journal | date=2008 | volume=684 | issue=2 | pages=1390–1403 | doi = 10.1086/590073 | arxiv = 0805.1059v2 | bibcode = 2008ApJ...684.1390R }} 6. ^{{cite journal|last=Cruz|first=Kelle L.|last2 = Reid | first2 = I. Neill|last3 = Liebert | first3 = James | last4 = Kirkpatrick | first4 = J. Davy | last5 = Lowrance | first5 = Patrick J. | title = Meeting the Cool Neighbors. V. A 2MASS-Selected Sample of Ultracool Dwarfs | journal = The Astronomical Journal | date = 2003 | volume = 126 | issue = 5 | pages = 2421–2448 | doi = 10.1086/378607 | arxiv = astro-ph/0307429 | bibcode = 2003AJ....126.2421C }} 7. ^1 2 3 4 5 6 7 {{cite journal | last = Dieterich | first = Sergio B. | last2 = Henry | first2 = Todd J. | last3 = Jao | first3 = Wei-Chun | last4 = Winters | first4 = Jennifer G. | last5 = Hosey | first5 = Altonio D. | last6 = Riedel | first6 = Adric R. | last7 = Subasavage | first7 = John P. | title = The Solar Neighborhood XXXII. The Hydrogen Burning Limit | journal = The Astronomical Journal | volume = 147 | issue = 5 | at = article id 94 | date = May 2014 | doi = 10.1088/0004-6256/147/5/94 | bibcode = 2014AJ....147...94D | arxiv = 1312.1736 }} 8. ^{{cite journal|last=Reid|first=I. Neill|last2=Lewitus | first2 = E.| last3 = Allen | first3 = P. R.| last4 = Cruz | first4 = Kelle L.| last5 = Burgasser | first5 = Adam J. | title = A Search for Binary Systems among the Nearest L Dwarfs|journal=The Astronomical Journal | date = 2006 | volume = 132 | issue = 2 | pages = 891–901 | doi = 10.1086/505626| arxiv = astro-ph/0606331 | bibcode = 2006AJ....132..891R }} 9. ^{{cite journal | last = Antonova | first = A. | last2 = Doyle | first2 = J. G. | last3 = Hallinan | first3 = G. | last4 = Golden | first4 = A. | last5 = Koen | first5 = C. | title = Sporadic long-term variability in radio activity from a brown dwarf | journal = Astronomy and Astrophysics | date = 2 September 2007 | volume = 472 | issue = 1 | pages = 257–260 | doi = 10.1051/0004-6361:20077231 | arxiv = 0707.0634 | bibcode = 2007A&A...472..257A }} 10. ^1 {{cite press release | last=Garmany | first=Katy | title=NOAO/SOAR: Where do stars end and brown dwarfs begin? | url=http://www.noao.edu/news/2013/pr1311.php|publisher=National Optical Astronomy Observatory | date = 9 December 2013 | accessdate=14 December 2013 }} External links
3 : Lepus (constellation)|L-type stars|2MASS objects |
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