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Верзија на датум 15. јул 2021. у 22:27

Artist's concept of a T-type brown dwarf

Comparison: most brown dwarfs are slightly smaller than Jupiter (15–20%),^[1] but are still up to 80 times more massive due to greater density. Image is not to scale; Jupiter's radius is 10 times that of Earth, and the Sun's radius is 10 times that of Jupiter.

Смеђи патуљак (понекад браон патуљак или мрки патуљак) је субстеларни објекат чија маса је испод нивоа неопходног за одржавање фузионих реакција сагоревањем водоника (¹H) into helium in their cores, unlike main sequence stars. Смеђи патуљци имају масу између великих планета гасних џинова, и звезда најмање масе; горња граница је између 75^[2] и 80 маса Јупитера ( $M_{J}$ ). Тренутно траје дебата о томе који критеријум да се користи за разликовање смеђих патуљака од великих планета код смеђих патуљака врло малих маса (~13 $M_{J}$ ),^[3]^[4] и да ли је неопходно да су смеђи патуљци доводили до фузије у неком тренутку у својој историји. У сваком случају, смеђи патуљци тежи од 13 $M_{J}$ врше фузију деутеријума, а они изнад ~65 $M_{J}$ врше и фузију литијума. Једина планета за коју је познато да кружи око смеђег патуљка је 2M1207b.^[4]

Astronomers classify self-luminous objects by spectral class, a distinction intimately tied to the surface temperature, and brown dwarfs occupy types M, L, T, and Y.^[5]^[6] As brown dwarfs do not undergo stable hydrogen fusion they cool down over time, progressively passing through later spectral types as they age.

Despite their name, to the naked eye brown dwarfs would appear different colors depending on their temperature.^[5] The warmest are possibly orange or red,^[7] while cooler brown dwarfs would likely appear magenta to the human eye.^[5]^[8] Brown dwarfs may be fully convective, with no layers or chemical differentiation by depth.^[9]

Историја

Рано теоретисање

The objects now called "brown dwarfs" were theorized by Shiv S. Kumar in the 1960s to exist and were originally called black dwarfs,^[10] a classification for dark substellar objects floating freely in space that were not massive enough to sustain hydrogen fusion. However: (a) the term black dwarf was already in use to refer to a cold white dwarf; (b) red dwarfs fuse hydrogen; and (c) these objects may be luminous at visible wavelengths early in their lives. Because of this, alternative names for these objects were proposed, including planetarШаблон:Typo help inline and substar. In 1975, Jill Tarter suggested the term "brown dwarf", using "brown" as an approximate color.^[7]^[11]^[12]

The term "black dwarf" still refers to a white dwarf that has cooled to the point that it no longer emits significant amounts of light. However, the time required for even the lowest-mass white dwarf to cool to this temperature is calculated to be longer than the current age of the universe; hence such objects are expected to not yet exist.

Early theories concerning the nature of the lowest-mass stars and the hydrogen-burning limit suggested that a population I object with a mass less than 0.07 solar masses (M_☉) or a population II object less than 0.09 M_☉ would never go through normal stellar evolution and would become a completely degenerate star.^[13] The first self-consistent calculation of the hydrogen-burning minimum mass confirmed a value between 0.07 and 0.08 solar masses for population I objects.^[14]^[15]

Види још

Стеларни објекти
Субстеларни објекти
- Екстрасоларна планета
- Планетар

Извори

^ Sorahana, S.; et al. (2013). „On the Radii of Brown Dwarfs Measured with AKARI Near-infrared Spectroscopy”. The Astrophysical Journal. 767 (1): 77. Bibcode:2013ApJ...767...77S. arXiv:1304.1259 . doi:10.1088/0004-637X/767/1/77 . „We find that the brown dwarf radius ranges between 0.64-1.13 RJ with an average radius of 0.83 RJ.”
^ Boss, Alan (3. 4. 2001). „Are They Planets or What?” (на језику: енглески). Carnegie Institution of Washington. Архивирано из оригинала 28. 09. 2006. г. Приступљено 8. 6. 2006.
^ Boss, Alan (2001-04-03). „Are They Planets or What?”. Carnegie Institution of Washington. Архивирано из оригинала 2006-09-28. г. Приступљено 2006-06-08.
^ ^а ^б Nicholos Wethington (6. 10. 2008). „Dense Exoplanet Creates Classification Calamity”. Universetoday.com. Приступљено 30. 1. 2013.
^ ^а ^б ^в Burgasser, A. J. (јун 2008). „Brown dwarfs: Failed stars, super Jupiters” (PDF). Physics Today. 61 (6): 70—71. Bibcode:2008PhT....61f..70B. doi:10.1063/1.2947658. Архивирано из оригинала (PDF) 8. 5. 2013. г. Приступљено 11. 1. 2016.
^ Cushing, Michael C. (2014), „Ultracool Objects: L, T, and Y Dwarfs”, Ур.: Joergens, Viki, 50 Years of Brown Dwarfs – From Prediction to Discovery to Forefront of Research, Astrophysics and Space Science Library, 401, Springer, стр. 113—140, ISBN 978-3-319-01162-2, doi:10.1007/978-3-319-01162-2_7
^ ^а ^б Cain, Fraser (6. 1. 2009). „If Brown Isn't a Color, What Color are Brown Dwarfs?”. Приступљено 24. 9. 2013.
^ Burrows, A.; Hubbard, W.B.; Lunine, J.I.; Liebert, J. (2001). „The Theory of Brown Dwarfs and Extrasolar Giant Planets”. Reviews of Modern Physics. 73 (3): 719—765. Bibcode:2001RvMP...73..719B. S2CID 204927572. arXiv:astro-ph/0103383 . doi:10.1103/RevModPhys.73.719.
^ Ian O'Neill (13. 9. 2011). „Violent Storms Rage on Nearby Brown Dwarf”. Seeker.com.
^ Kumar, Shiv S. (1962). „Study of Degeneracy in Very Light Stars”. Astronomical Journal. 67: 579. Bibcode:1962AJ.....67S.579K. doi:10.1086/108658 .
^ Tarter, Jill (2014), „Brown is Not a Color: Introduction of the Term 'Brown Dwarf'”, Ур.: Joergens, Viki, 50 Years of Brown Dwarfs – From Prediction to Discovery to Forefront of Research, Astrophysics and Space Science Library, 401, Springer, стр. 19—24, ISBN 978-3-319-01162-2, doi:10.1007/978-3-319-01162-2_3
^ Croswell, Ken (1999). Planet Quest: The Epic Discovery of Alien Solar Systems. Oxford University Press. стр. 118—119. ISBN 9780192880833.
^ Kumar, S. (1963). „The Structure of Stars of Very Low Mass”. Astrophysical Journal. 137: 1121. Bibcode:1963ApJ...137.1121K. doi:10.1086/147589.
^ Hayashi, C.; Nakano, T. (1963). „Evolution of Stars of Small Masses in the Pre-Main-Sequence Stages”. Progress of Theoretical Physics. 30 (4): 460—474. Bibcode:1963PThPh..30..460H. doi:10.1143/PTP.30.460 .
^ Nakano, Takenori (2014), „Pre-main Sequence Evolution and the Hydrogen-Burning Minimum Mass”, Ур.: Joergens, Viki, 50 Years of Brown Dwarfs – From Prediction to Discovery to Forefront of Research, Astrophysics and Space Science Library, 401, Springer, стр. 5—17, ISBN 978-3-319-01162-2, doi:10.1007/978-3-319-01162-2_2

Литература

Kirkpatrick, Davy; Burgasser, Adam (6. 11. 2012). „Photometry, spectroscopy, and astrometry of M, L, and T dwarfs”. DwarfArchives.org. Pasadena, CA: California Institute of Technology. Приступљено 2012-12-28.
Hansen, Carl J.; Kawaler, Steven D.; Trimble, Virginia (2004). Stellar interiors: physical principles, structure, and evolution (2nd изд.). Springer-Verlag. ISBN 0-387-20089-4.
Prialnik, Dina (2000). An Introduction to the Theory of Stellar Structure and Evolution. Cambridge University Press. ISBN 0-521-65065-8.
Ryan, Sean G.; Norton, Andrew J. (2010). Stellar Evolution and Nucleosynthesis. Cambridge University Press. ISBN 978-0-521-13320-3.
Astronomy 606 (Stellar Structure and Evolution) lecture notes, Cole Miller, Department of Astronomy, University of Maryland
Astronomy 162, Unit 2 (The Structure & Evolution of Stars) lecture notes, Richard W. Pogge, Department of Astronomy, Ohio State University
Demarque, P.; Guenther, D. B.; Li, L. H.; Mazumdar, A.; Straka, C. W. (август 2008). „YREC: the Yale rotating stellar evolution code”. Astrophysics and Space Science. 316 (1–4): 31—41. Bibcode:2008Ap&SS.316...31D. ISBN 9781402094408. arXiv:0710.4003 . doi:10.1007/s10509-007-9698-y.
D'Amico, N.; Stappers, B. W.; Bailes, M.; Martin, C. E.; Bell, J. F.; Lyne, A. G.; Manchester, R. N. (1998). „The Parkes Southern Pulsar Survey - III. Timing of long-period pulsars”. Monthly Notices of the Royal Astronomical Society. 297 (1): 28—40. Bibcode:1998MNRAS.297...28D. doi:10.1046/j.1365-8711.1998.01397.x .
Ken'ichi Nomoto; Yoji Kondo (1991). „Conditions for accretion-induced collapse of white dwarfs”. Astrophysical Journal. 367: L19—L22. Bibcode:1991ApJ...367L..19N. doi:10.1086/185922.

Спољашње везе

HubbleSite newscenter – Weather patterns on a brown dwarf
Allard, France; Homeier, Derek (2007). „Brown dwarfs”. Scholarpedia. 2 (12): 4475. Bibcode:2007SchpJ...2.4475A. doi:10.4249/scholarpedia.4475 .
Stellar evolution simulator
Pisa Stellar Models
MESA stellar evolution codes (Modules for Experiments in Stellar Astrophysics)
"The Life of Stars", BBC Radio 4 discussion with Paul Murdin, Janna Levin and Phil Charles (In Our Time, Mar. 27, 2003)

Историја

S. S. Kumar, Low-Luminosity Stars. Gordon and Breach, London, 1969—an early overview paper on brown dwarfs
The Columbia Encyclopedia

Детаљи

A current list of L and T dwarfs
A geological definition of brown dwarfs, contrasted with stars and planets (via Berkeley)
Neill Reid's pages at the Space Telescope Science Institute:
- On spectral analysis of M dwarfs, L dwarfs, and T dwarfs
- Temperature and mass characteristics of low-temperature dwarfs
First X-ray from brown dwarf observed, Spaceref.com, 2000
Brown Dwarfs and ultracool dwarfs (late-M, L, T)—D. Montes, UCM
Wild Weather: Iron Rain on Failed Stars—scientists are investigating astonishing weather patterns on brown dwarfs, Space.com, 2006
NASA Brown dwarf detectives—Detailed information in a simplified sense
Brown Dwarfs—Website with general information about brown dwarfs (has many detailed and colorful artist's impressions)

Звезде

Cha Halpha 1 stats and history
A census of observed brown dwarfs (not all confirmed), ca 1998
Luhman et al, Discovery of a Planetary-Mass Brown Dwarf with a Circumstellar Disk
Discovery Narrows the Gap Between Planets and Brown Dwarfs, 2007
Y-Spectral class for Ultra-Cool Dwarfs, N.R.Deacon and N.C.Hambly, 2006

[SorahanaYamamura2013-1] Sorahana, S.; et al. (2013). „On the Radii of Brown Dwarfs Measured with AKARI Near-infrared Spectroscopy”. The Astrophysical Journal. 767 (1): 77. Bibcode:2013ApJ...767...77S. arXiv:1304.1259 . doi:10.1088/0004-637X/767/1/77 . „We find that the brown dwarf radius ranges between 0.64-1.13 RJ with an average radius of 0.83 RJ.”

[2] Boss, Alan (3. 4. 2001). „Are They Planets or What?” (на језику: енглески). Carnegie Institution of Washington. Архивирано из оригинала 28. 09. 2006. г. Приступљено 8. 6. 2006.

[BossCarnegie-3] Boss, Alan (2001-04-03). „Are They Planets or What?”. Carnegie Institution of Washington. Архивирано из оригинала 2006-09-28. г. Приступљено 2006-06-08.

[Wethington-4] а ^б Nicholos Wethington (6. 10. 2008). „Dense Exoplanet Creates Classification Calamity”. Universetoday.com. Приступљено 30. 1. 2013.

[PT-June2008-5] а ^б ^в Burgasser, A. J. (јун 2008). „Brown dwarfs: Failed stars, super Jupiters” (PDF). Physics Today. 61 (6): 70—71. Bibcode:2008PhT....61f..70B. doi:10.1063/1.2947658. Архивирано из оригинала (PDF) 8. 5. 2013. г. Приступљено 11. 1. 2016.

[MichaelCushing2014-6] Cushing, Michael C. (2014), „Ultracool Objects: L, T, and Y Dwarfs”, Ур.: Joergens, Viki, 50 Years of Brown Dwarfs – From Prediction to Discovery to Forefront of Research, Astrophysics and Space Science Library, 401, Springer, стр. 113—140, ISBN 978-3-319-01162-2, doi:10.1007/978-3-319-01162-2_7

[Cain-7] а ^б Cain, Fraser (6. 1. 2009). „If Brown Isn't a Color, What Color are Brown Dwarfs?”. Приступљено 24. 9. 2013.

[Burrows2001-8] Burrows, A.; Hubbard, W.B.; Lunine, J.I.; Liebert, J. (2001). „The Theory of Brown Dwarfs and Extrasolar Giant Planets”. Reviews of Modern Physics. 73 (3): 719—765. Bibcode:2001RvMP...73..719B. S2CID 204927572. arXiv:astro-ph/0103383 . doi:10.1103/RevModPhys.73.719.

[9] Ian O'Neill (13. 9. 2011). „Violent Storms Rage on Nearby Brown Dwarf”. Seeker.com.

[10] Kumar, Shiv S. (1962). „Study of Degeneracy in Very Light Stars”. Astronomical Journal. 67: 579. Bibcode:1962AJ.....67S.579K. doi:10.1086/108658 .

[JillTarter2014-11] Tarter, Jill (2014), „Brown is Not a Color: Introduction of the Term 'Brown Dwarf'”, Ур.: Joergens, Viki, 50 Years of Brown Dwarfs – From Prediction to Discovery to Forefront of Research, Astrophysics and Space Science Library, 401, Springer, стр. 19—24, ISBN 978-3-319-01162-2, doi:10.1007/978-3-319-01162-2_3

[12] Croswell, Ken (1999). Planet Quest: The Epic Discovery of Alien Solar Systems. Oxford University Press. стр. 118—119. ISBN 9780192880833.

[Kumar1963-13] Kumar, S. (1963). „The Structure of Stars of Very Low Mass”. Astrophysical Journal. 137: 1121. Bibcode:1963ApJ...137.1121K. doi:10.1086/147589.

[Hayashi1963-14] Hayashi, C.; Nakano, T. (1963). „Evolution of Stars of Small Masses in the Pre-Main-Sequence Stages”. Progress of Theoretical Physics. 30 (4): 460—474. Bibcode:1963PThPh..30..460H. doi:10.1143/PTP.30.460 .

[Nakano2014-15] Nakano, Takenori (2014), „Pre-main Sequence Evolution and the Hydrogen-Burning Minimum Mass”, Ур.: Joergens, Viki, 50 Years of Brown Dwarfs – From Prediction to Discovery to Forefront of Research, Astrophysics and Space Science Library, 401, Springer, стр. 5—17, ISBN 978-3-319-01162-2, doi:10.1007/978-3-319-01162-2_2

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@@ Ред 1: / Ред 1: @@
+{{short description|Тип подзвезданог објекта већи од гасног гиганта}}{{rut}}
-[[Датотека:Brown Dwarf Gliese 229B.jpg|мини|250п|десно|Смеђи патуљак (мањи објекат) кружи око звезде [[Gliese 229]], која се налази у сазвежђу [[Зец (сазвежђе)|Зец]], око 19 [[светлосна година|светлосних година]] од Земље. Смеђи патуљак, [[Gliese 229b]], има масу око 20 до 50 пута већу од масе Јупитера.]]
+{{multiple image
-'''Смеђи патуљак''' (понекад '''браон патуљак''' или '''мрки патуљак''') је субстеларни објекат чија маса је испод нивоа неопходног за одржавање фузионих реакција сагоревањем [[водоник]]а. Смеђи патуљци имају масу између великих [[планета]] [[планета Јупитеровог типа|гасних џинова]], и [[звезда]] најмање масе; горња граница је између 75<ref>{{cite web | first = Alan | last = Boss | date = 3. 4. 2001. | url = http://www.carnegieinstitution.org/News4-3,2001.html | title = Are They Planets or What? | publisher = Carnegie Institution of Washington | language = English | accessdate = 8. 6. 2006. | archive-url = https://web.archive.org/web/20060928065124/http://www.carnegieinstitution.org/News4-3,2001.html | archive-date = 28. 09. 2006 |url-status=dead | df =  }}</ref> и 80 маса [[Јупитер]]а (<math>M_J</math>). Тренутно траје дебата о томе који критеријум да се користи за разликовање смеђих патуљака од великих планета код смеђих патуљака врло малих маса (~13 <math>M_J</math> ), и да ли је неопходно да су смеђи патуљци доводили до фузије у неком тренутку у својој историји. У сваком случају, смеђи патуљци тежи од 13 <math>M_J</math> врше фузију [[деутеријум]]а, а они изнад ~65 <math>M_J</math> врше и фузију [[литијум]]а. Једина планета за коју је познато да кружи око смеђег патуљка је [[2M1207b]].
+| direction = vertical
+| align = right
+| width = 275
+| image1 = Artist’s conception of a brown dwarf like 2MASSJ22282889-431026.jpg
+| caption1 = Artist's concept of a T-type brown dwarf
+| image2 = Brown_Dwarf_Comparison_2020.png
+| caption2 = Comparison: most brown dwarfs are slightly smaller than Jupiter (15–20%),<ref name="SorahanaYamamura2013">{{cite journal|last1=Sorahana|first1=S.|last2=Yamamura|first2=I.|last3=Murakami|first3=H.|display-authors=1|title=On the Radii of Brown Dwarfs Measured with AKARI Near-infrared Spectroscopy|journal=The Astrophysical Journal|volume=767|issue=1|year=2013|pages=77|doi=10.1088/0004-637X/767/1/77|arxiv=1304.1259|bibcode=2013ApJ...767...77S|doi-access=free|quote=We find that the brown dwarf radius ranges between 0.64-1.13 RJ with an average radius of 0.83 RJ.}}</ref> but are still up to 80 times more massive due to greater density. Image is not to scale; Jupiter's radius is 10 times that of Earth, and the Sun's radius is 10 times that of Jupiter.}}
+[[Датотека:Brown Dwarf Gliese 229B.jpg|мини|275п|десно|Смеђи патуљак (мањи објекат) кружи око звезде [[Gliese 229]], која се налази у сазвежђу [[Зец (сазвежђе)|Зец]], око 19 [[светлосна година|светлосних година]] од Земље. Смеђи патуљак, [[Gliese 229b]], има масу око 20 до 50 пута већу од масе Јупитера.]]
+'''Смеђи патуљак''' (понекад '''браон патуљак''' или '''мрки патуљак''') је [[substellar object|субстеларни објекат]] чија маса је испод нивоа неопходног за одржавање [[Nuklearna fuzija|фузионих реакција]] сагоревањем [[водоник]]а ([[hydrogen-1|<sup>1</sup>-{H}-]]) into helium in their cores, unlike [[main sequence]] stars. Смеђи патуљци имају масу између великих [[планета]] [[планета Јупитеровог типа|гасних џинова]], и [[звезда]] најмање масе; горња граница је између 75<ref>{{cite web | first = Alan | last = Boss | date = 3. 4. 2001. | url = http://www.carnegieinstitution.org/News4-3,2001.html | title = Are They Planets or What? | publisher = Carnegie Institution of Washington | language = English | accessdate = 8. 6. 2006. | archive-url = https://web.archive.org/web/20060928065124/http://www.carnegieinstitution.org/News4-3,2001.html | archive-date = 28. 09. 2006 |url-status=dead | df =  }}</ref> и 80 маса [[Јупитер]]а (<math>M_J</math>). Тренутно траје дебата о томе који критеријум да се користи за разликовање смеђих патуљака од [[Планета Јупитеровог типа|великих]] планета код смеђих патуљака врло малих маса (~13 <math>M_J</math> ),<ref name="BossCarnegie">{{cite web |first=Alan |last=Boss |date=2001-04-03 |url=http://www.carnegieinstitution.org/News4-3,2001.html |title=Are They Planets or What? |publisher=Carnegie Institution of Washington |access-date=2006-06-08 |archive-url=https://web.archive.org/web/20060928065124/http://www.carnegieinstitution.org/News4-3%2C2001.html |archive-date=2006-09-28 |url-status=dead }}</ref><ref name="Wethington" /> и да ли је неопходно да су смеђи патуљци доводили до фузије у неком тренутку у својој историји. У сваком случају, смеђи патуљци тежи од 13 <math>M_J</math> врше фузију [[деутеријум]]а, а они изнад ~65 <math>M_J</math> врше и фузију [[литијум]]а. Једина планета за коју је познато да кружи око смеђег патуљка је [[2M1207b]].<ref name="Wethington">{{cite news |url=http://www.universetoday.com/19237/dense-exoplanet-creates-classification-calamity/ |title=Dense Exoplanet Creates Classification Calamity |author=Nicholos Wethington |work=Universetoday.com |date=October 6, 2008 |access-date=January 30, 2013}}</ref>
-== Извори ==
-{{reflist}}
+Astronomers classify self-luminous objects by [[spectral classification|spectral class]], a distinction intimately tied to the surface temperature, and brown dwarfs occupy types M, L, T, and Y.<ref name="PT-June2008">{{cite journal |last=Burgasser |first=A. J. |title=Brown dwarfs: Failed stars, super Jupiters |url=http://astro.berkeley.edu/~gmarcy/astro160/papers/brown_dwarfs_failed_stars.pdf |date=June 2008 |journal=[[Physics Today]] |volume=61 |issue=6 |pages=70–71 |access-date=11 January 2016 |bibcode=2008PhT....61f..70B |doi=10.1063/1.2947658 |archive-url=https://web.archive.org/web/20130508182012/http://astro.berkeley.edu/~gmarcy/astro160/papers/brown_dwarfs_failed_stars.pdf |archive-date=8 May 2013 |url-status=dead }}</ref><ref name="MichaelCushing2014">{{citation |last=Cushing |first=Michael C. |chapter=Ultracool Objects: L, T, and Y Dwarfs |pages=113–140 |editor-last=Joergens |editor-first=Viki |title=50 Years of Brown Dwarfs – From Prediction to Discovery to Forefront of Research |series=Astrophysics and Space Science Library |volume=401 |publisher=Springer |publication-date=2014 |isbn=978-3-319-01162-2 |chapter-url=https://www.springer.com/astronomy/book/978-3-319-01161-5|doi=10.1007/978-3-319-01162-2_7 |year=2014 }}</ref> As brown dwarfs do not undergo stable hydrogen fusion they cool down over time, progressively passing through later spectral types as they age.
+Despite their name, to the naked eye brown dwarfs would appear different colors depending on their temperature.<ref name="PT-June2008" /> The warmest are possibly orange or red,<ref name="Cain">{{cite web |last=Cain |first=Fraser |title=If Brown Isn't a Color, What Color are Brown Dwarfs? |url=http://www.universetoday.com/23247/if-brown-isnt-a-color-what-color-are-brown-dwarfs/ |access-date=24 September 2013 |date=January 6, 2009}}</ref> while cooler brown dwarfs would likely appear [[magenta]] to the human eye.<ref name="PT-June2008" /><ref name=Burrows2001>{{cite journal |last1=Burrows |first1=A. |last2=Hubbard |first2=W.B. |last3=Lunine |first3=J.I. |last4=Liebert |first4=J. |title=The Theory of Brown Dwarfs and Extrasolar Giant Planets |journal=Reviews of Modern Physics |volume=73 |issue=3 |year=2001 |doi=10.1103/RevModPhys.73.719 |bibcode=2001RvMP...73..719B |arxiv=astro-ph/0103383 |pages=719–765|s2cid=204927572}}</ref> Brown dwarfs may be fully [[convective]], with no layers or chemical differentiation by depth.<ref>{{cite web |url=https://www.seeker.com/violent-storms-rage-on-nearby-brown-dwarf-1765411574.html |title=Violent Storms Rage on Nearby Brown Dwarf |author=Ian O'Neill |publisher=Seeker.com |date=13 September 2011}}</ref>
+== Историја ==
+=== Рано теоретисање  ===
+[[File:PIA23685-Planets-BrownDwarfs-Stars.jpg|thumb|left|200px|Planets, brown dwarfs, stars]]
+The objects now called "brown dwarfs" were theorized by Shiv S. Kumar in the 1960s to exist and were originally called [[black dwarf]]s,<ref>{{cite journal |last=Kumar |first=Shiv S. |title=Study of Degeneracy in Very Light Stars |journal=Astronomical Journal |volume=67 |page=579 |date=1962 |doi=10.1086/108658 |bibcode=1962AJ.....67S.579K|doi-access=free }}</ref> a classification for dark substellar objects floating freely in space that were not massive enough to sustain hydrogen fusion. However: (a)&nbsp;the term black dwarf was already in use to refer to a cold [[white dwarf]]; (b)&nbsp;[[red dwarf]]s fuse hydrogen; and (c)&nbsp;these objects may be luminous at visible wavelengths early in their lives. Because of this, alternative names for these objects were proposed, including planetar{{typo help inline|reason=similar to planetary|date=June 2021}} and [[Substellar object|substar]]. In 1975, [[Jill Tarter]] suggested the term "brown dwarf", using "brown" as an approximate color.<ref name="Cain" /><ref name="JillTarter2014">{{citation |last=Tarter |first=Jill |chapter=Brown is Not a Color: Introduction of the Term 'Brown Dwarf' |pages=19–24 |editor-last=Joergens |editor-first=Viki |title=50 Years of Brown Dwarfs – From Prediction to Discovery to Forefront of Research |series=Astrophysics and Space Science Library |volume=401 |publisher=Springer |publication-date=2014 |isbn=978-3-319-01162-2 |chapter-url=https://www.springer.com/astronomy/book/978-3-319-01161-5|doi=10.1007/978-3-319-01162-2_3 |year=2014 }}</ref><ref>{{cite book|last1=Croswell|first1=Ken|title=Planet Quest: The Epic Discovery of Alien Solar Systems|date=1999|publisher=Oxford University Press|isbn=9780192880833|pages=118–119}}</ref>
+The term "black dwarf" still refers to a [[white dwarf]] that has cooled to the point that it no longer emits significant amounts of light. However, the time required for even the lowest-mass white dwarf [[White dwarf#Radiation and cooling|to cool to this temperature]] is calculated to be longer than the current age of the universe; hence such objects are expected to not yet exist.
+Early theories concerning the nature of the lowest-mass stars and the hydrogen-burning limit suggested that a [[population I]] object with a mass less than 0.07&nbsp;[[solar mass]]es ({{Solar mass|link=y}}) or a [[population II]] object less than {{Solar mass|0.09}} would never go through normal [[stellar evolution]] and would become a completely [[degenerate star]].<ref name="Kumar1963">{{cite journal|last=Kumar|first=S.|date=1963|title=The Structure of Stars of Very Low Mass|journal=Astrophysical Journal|volume=137|page=1121|bibcode=1963ApJ...137.1121K|doi=10.1086/147589}}</ref> The first self-consistent calculation of the hydrogen-burning minimum mass confirmed a value between 0.07 and 0.08&nbsp;solar masses for population I objects.<ref name="Hayashi1963">{{cite journal|last2=Nakano|first2=T.|date=1963|title=Evolution of Stars of Small Masses in the Pre-Main-Sequence Stages|journal=Progress of Theoretical Physics|volume=30|pages=460–474|bibcode=1963PThPh..30..460H|doi=10.1143/PTP.30.460|last1=Hayashi|first1=C.|number=4|doi-access=free}}</ref><ref name=Nakano2014>{{citation |last=Nakano |first=Takenori |chapter=Pre-main Sequence Evolution and the Hydrogen-Burning Minimum Mass |pages=5–17 |editor-last=Joergens |editor-first=Viki |title=50 Years of Brown Dwarfs – From Prediction to Discovery to Forefront of Research |series=Astrophysics and Space Science Library |volume=401 |publisher=Springer |publication-date=2014 |isbn=978-3-319-01162-2 |chapter-url=https://www.springer.com/astronomy/book/978-3-319-01161-5|doi=10.1007/978-3-319-01162-2_2 |year=2014 }}</ref>
 == Види још ==
@@ Ред 15: / Ред 36: @@
 ** [[Екстрасоларне планете|Екстрасоларна планета]]
 ** [[Планетар (астрономија)|Планетар]]
+== Извори ==
+{{reflist}}
+== Литература ==
+{{refbegin|}}
+* {{cite web
+ |first1=Davy |last1=Kirkpatrick |author1-link=J. Davy Kirkpatrick
+ |first2=Adam |last2=Burgasser
+ |date=6 November 2012
+ |title=Photometry, spectroscopy, and astrometry of M, L, and T dwarfs
+ |website=DwarfArchives.org
+ |publisher=California Institute of Technology
+ |place=Pasadena, CA
+ |url=http://spider.ipac.caltech.edu/staff/davy/ARCHIVE/index.shtml
+ |access-date=2012-12-28 }}
+* {{cite book | last1=Hansen | first1=Carl J. | last2=Kawaler | first2=Steven D. | last3=Trimble | first3=Virginia | title= Stellar interiors: physical principles, structure, and evolution | date=2004 | edition=2nd | publisher=Springer-Verlag | isbn=0-387-20089-4}}
+* {{cite book | first=Dina | last=Prialnik | title=An Introduction to the Theory of Stellar Structure and Evolution | date=2000 | publisher=Cambridge University Press | isbn=0-521-65065-8}}
+* {{cite book | title= Stellar Evolution and Nucleosynthesis | first1=Sean G. | last1=Ryan | first2=Andrew J. | last2=Norton | isbn= 978-0-521-13320-3 | publisher=Cambridge University Press | date=2010}}
+* [http://www.astro.umd.edu/~miller/teaching/astr606/ Astronomy 606 (Stellar Structure and Evolution) lecture notes], Cole Miller, Department of Astronomy, [[University of Maryland, College Park|University of Maryland]]
+* [http://www.astronomy.ohio-state.edu/~pogge/Ast162/Unit2/ Astronomy 162, Unit 2 (The Structure & Evolution of Stars) lecture notes], Richard W. Pogge, Department of Astronomy, [[Ohio State University]]
+* {{cite journal | last1=Demarque | first1=P. | last2=Guenther | first2=D. B. | last3=Li | first3=L. H. | last4=Mazumdar | first4=A. | last5=Straka | first5=C. W. |date=August 2008 | title=YREC: the Yale rotating stellar evolution code | journal=Astrophysics and Space Science | volume=316 | issue=1–4 | pages=31–41 | doi=10.1007/s10509-007-9698-y | bibcode=2008Ap&SS.316...31D | arxiv = 0710.4003 | isbn=9781402094408}}
+* {{cite journal | author=D'Amico, N. | author2=Stappers, B. W. | author3=Bailes, M. | author4=Martin, C. E. | author5=Bell, J. F. | author6=Lyne, A. G. | author7=Manchester, R. N. | journal=Monthly Notices of the Royal Astronomical Society | date=1998 | doi=10.1046/j.1365-8711.1998.01397.x | volume=297 | issue=1 | pages=28–40|bibcode = 1998MNRAS.297...28D | title=The Parkes Southern Pulsar Survey - III. Timing of long-period pulsars | doi-access=free }}
+* {{cite journal |author=Ken'ichi Nomoto |author2=Yoji Kondo |title=Conditions for accretion-induced collapse of white dwarfs |journal=Astrophysical Journal |date=1991 |volume=367 |pages=L19–L22 |bibcode=1991ApJ...367L..19N |doi=10.1086/185922}}
+{{refend}}
 == Спољашње везе ==
 {{Commonscat|Brown dwarfs}}
+{{refbegin|30em}}
+* [http://hubblesite.org/newscenter/archive/releases/2013/02/image/a/ HubbleSite newscenter – Weather patterns on a brown dwarf]
+* {{cite journal | last1 = Allard | first1 = France | author-link = France Allard | author-link2 = Derek Homeier | last2 = Homeier | first2 = Derek | year = 2007 | title = Brown dwarfs | journal = [[Scholarpedia]] | volume = 2 | issue = 12 | page = 4475 | doi = 10.4249/scholarpedia.4475 | bibcode = 2007SchpJ...2.4475A | doi-access = free }}
+* [http://spiff.rit.edu/classes/phys230/lectures/star_age/evol_hr.swf Stellar evolution simulator]
+* [http://astro.df.unipi.it/stellar-models/ Pisa Stellar Models]
+* [http://mesa.sourceforge.net/ MESA stellar evolution codes (Modules for Experiments in Stellar Astrophysics)]
+* [http://www.bbc.co.uk/programmes/p00548w8 "The Life of Stars"], BBC Radio 4 discussion with Paul Murdin, Janna Levin and Phil Charles (''In Our Time'', Mar. 27, 2003)
+=== Историја ===
+* S. S. Kumar, ''Low-Luminosity Stars''. Gordon and Breach, London, 1969—an early overview paper on brown dwarfs
+* [https://web.archive.org/web/20050114164835/http://www.bartleby.com/65/br/browndwa.html The Columbia Encyclopedia]
+=== Детаљи ===
+* [http://www.dwarfarchives.org/ A current list of L and T dwarfs]
+* [https://web.archive.org/web/20050224110208/http://astron.berkeley.edu/~stars/bdwarfs/structbd.html A geological definition of brown dwarfs], contrasted with stars and planets (via Berkeley)
+* Neill Reid's pages at the [[Space Telescope Science Institute]]:
+** [https://archive.today/20121215095626/http://www-int.stsci.edu/~inr/ldwarf1.html On spectral analysis] of [[M dwarf]]s, [[L dwarf]]s, and [[T dwarf]]s
+** [https://archive.today/20130521055905/http://www-int.stsci.edu/~inr/ldwarf3.html Temperature and mass characteristics] of low-temperature dwarfs
+* [http://www.spaceref.com/news/viewpr.html?pid=2192 First X-ray from brown dwarf observed], Spaceref.com, 2000
+* [http://www.ucm.es/info/Astrof/recopilaciones/enanasmarrones.html Brown Dwarfs and ultracool dwarfs (late-M, L, T)]—[[D. Montes]], UCM
+* [http://www.space.com/scienceastronomy/060703_mystery_monday.html Wild Weather: Iron Rain on Failed Stars]—scientists are investigating astonishing weather patterns on brown dwarfs, Space.com, 2006
+* [http://www.nasa.gov/vision/universe/starsgalaxies/brown_dwarf_detectives.html NASA Brown dwarf detectives]—Detailed information in a simplified sense
+* [http://www.darkstar1.co.uk/ds3.htm Brown Dwarfs]—Website with general information about brown dwarfs (has many detailed and colorful artist's impressions)
+=== Звезде ===
+* [https://web.archive.org/web/20051201132115/http://ssc.spitzer.caltech.edu/documents/compendium/cha_halpha1/ Cha Halpha 1] stats and history
+* [https://web.archive.org/web/20050212200244/http://astron.berkeley.edu/~stars/bdwarfs/observbd.html A census of observed brown dwarfs] (not all confirmed), ca 1998
+* [http://www.iop.org/EJ/article/1538-4357/635/1/L93/20043.html Luhman et al, Discovery of a Planetary-Mass Brown Dwarf with a Circumstellar Disk]
+* [https://web.archive.org/web/20070609130324/http://www.gemini.edu/index.php?option=content&task=view&id=232 Discovery Narrows the Gap Between Planets and Brown Dwarfs, 2007]
+* [https://arxiv.org/abs/astro-ph/0607305 Y-Spectral class for Ultra-Cool Dwarfs, N.R.Deacon and N.C.Hambly, 2006]
+{{refend}}
+{{Authority control}}
 [[Категорија:Браон патуљци|*]]
 [[Категорија:Звезде]]
-[[Категорија:Типови планета]]
+[[Категорија:Типови звезда]]

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