Jump to content

Y dwarf

From Wikipedia, the free encyclopedia
(Redirected from Y class dwarf)

An object with a spectral type Y (also called Y dwarf) is either a brown dwarf or a free-floating planetary-mass object. They have temperatures below around 500 Kelvin (227°C; 440°F) and are colder than T-dwarfs.[1][2] Y-dwarfs have a similar spectrum when compared to the giant planet Jupiter.[3]

Early theories and discovery

[edit]
James Webb Space Telescope images, showing the movement of WISE 0855-0714, the coldest Y-dwarf

When the spectral classes of L dwarfs and T dwarfs were defined it was mentioned that the letter Y was available for an additional spectral class.[4] In the early 2000s it was already theorized that objects "beyond the T dwarfs" should exist and that these objects would bridge the gap between T dwarfs and the giant planets of the Solar System. Objects colder than T dwarfs would primarily emit infrared as thermal radiation, so observations and discoveries with infrared telescopes such as WISE, Spitzer and James Webb Space Telescope were anticipated. Modelling of such cold objects predicted the disappearance of the sodium (Na D) and potassium (K I) features at around 500 K and the appearance of water clouds at around 400–500 K. Ammonia clouds were predicted to exist below around 160 K.[5] The formation of these clouds were theorized earlier in the Sudarsky's gas giant classification.[6]

After some candidates were proposed in 2010 and 2011,[7][8][9] a larger sample of Y-dwarfs were discovered with WISE and the Y-dwarf spectral type was established, using UGPS 0722-05 as the T9 standard and WISE 1738+2732 as the Y0 standard.[1][2] A significant discovery was the discovery of WISE J0855−0714, which remains the coldest and closest Y-dwarf discovered.[10] It has a temperature of 285 K (12 °C; 53 °F) and has the latest spectral type of Y4.[11]

The Y-class

[edit]
Spectrum of WISE 0359−5401 with JWST, showing different molecular absorption bands.

A Y-dwarf is characterized by its deep methane (CH4) and water vapor (H2O) bands, as well as a narrower J-band peak than the T9 standard. The J-band peak will get narrower with a spectral type later than T8. Early observations also showed evidence of ammonia (NH3) in the near-infrared spectrum.[1][2] Modern observations with JWST detect CH4, H2O, NH3, carbon monoxide (CO) and carbon dioxide (CO2) in the atmosphere of Y-dwarfs. Phosphine (PH3) is missing from the atmosphere, despite being predicted to be present.[12][13] JWST observations showed that models under-predict the abundance of CO2 and over-predict PH3 for late T and Y dwarfs. Proposed explanations for the missing PH3 are that it condenses into clouds of ammonium dihydrogen phosphate (NH4H2PO4), an incomplete understanding of phosphorus chemistry or a different mixing of the atmosphere. The overabundance of CO2 is explained with a better understanding of the CO2 chemistry in respect to CO chemistry.[14] CH4, H2O and NH3 absorption features get deeper with lower temperature. The 5 μm peak does not show such a correlation and instead shows a large diversity. This region is influenced by multiple molecules, including CO and CO2, which vary a lot between sources. The reason for this variation could be due to a different surface gravity or due to differences in metallicity.[13][15] CO2 was noted to slightly decrease from T dwarfs to Y dwarfs, but not CO.[15] Hydrogen sulfide (H2S) is used to improve the spectral fits of T- and Y-dwarfs. Currently the only Y-dwarfs with detected H2S are WISE 1828+26 and WISE 0359−5401.[16]

Colder lower atmosphere

[edit]

Usually brown dwarfs have a pressure–temperature (P–T) profile in an adiabatic form, which means that the pressure and temperature increase with depth. JWST spectroscopy and photometry suggest that Y-dwarfs have P–T profiles that are not in the standard adiabatic form. This means that upper layers of the atmosphere have a warmer temperature and lower layers of the atmosphere have a colder temperature. This is explained by the rapid rotation of these isolated objects. The rapid rotation leads to dynamical, thermal, and chemical changes, which disrupt the convective transport of heat from the lower to the upper atmosphere. This different P–T profile influences the shape of the spectrum and influences the composition of carbon- and nitrogen-bearing molecules in the atmospheres of Y-dwarfs.[17]

Clouds and variability

[edit]

Water clouds were theorized since the early 2000s to exist in Y-dwarfs.[6][5] The Y-dwarfs do however likely also have clouds made of other condensates, such as sulfides, potassium chloride (KCl) and possibly ammonium dihydrogen phosphate (NH4H2PO4). These clouds would exist below any water clouds for colder Y-dwarfs.[18] Some Y-dwarfs are likely too warm to form water clouds, but could have other observable clouds.[19] The first discovered variable Y-dwarf was WISE 1405+5534 (Y0) and its variability is modelled with a single bright spot.[20] Another variable Y dwarf is WISE 1738+2732 (Y0) and its variability is explained with the breakup of KCl and sodium sulfide (Na2S) clouds into a patchy cloud cover.[19] WISE 0855−0714 (Y4) is suspected to have water ice clouds, which should produce large amplitude variations. It does show relatively small variations of 4–5%, which could mean that both hemispheres have a similar cloud cover.[21]

Peculiar Y-dwarfs

[edit]
Aurora in CWISEP J1935-1546 detected by its methane emission

Currently only the suffix pec, standing for "peculiar" or unusual, exists for Y-dwarfs. Any spectral peculiarity is denoted this way, such as the Y-band peak and Y-J color of WISE 1639−6847 (Y0pec), which is different from other Y-dwarfs.[22] In some cases the peculiarity is explained with a non-solar metallicity or an unusual surface gravity. An example is CWISE J1055+5443, for which researchers find that low gravity models fit the spectrum better, likely due to a young age.[23] JWST observations found two Y-dwarfs with unusual spectral features of the carbon-bearing molecules. CWISEP J1047+54 showed abnormally strong CO and CO2 and likely weaker CH4.[13] Similar strong CO and CO2 absorption features were found in WISE J1206+8401.[15] WISE J0535−75 on the other hand showed no discernable CO2 and almost undetectable CO, but it also showed stronger NH3 absorption when compared to Y-dwarfs with similar temperature.[13] Another notable spectral discovery with JWST is the emission of methane in CWISEP J1935-1546, which is interpreted with the presence of an aurora.[24] One of the first suspected Y-type subdwarfs is WISEA J1534−1043, which shows an unusual blue color. Spectroscopic observations are however required to confirm this hypothesis.[25]

Exoplanets and companions

[edit]

Masses estimated for Y-dwarfs are between 3–29 MJ, but more typically below 21 MJ. This makes them similar to massive exoplanets.[26][27][28]

There is only one confirmed Y-dwarf that co-moves with a white dwarf, called WD 0806−661 B.[29] Though of planetary mass, Rodriguez et al. suggest it is unlikely to have formed in the same manner as planets.[8] Additionally there is the T/Y companion Ross 19B, which orbits a main-sequence star.[30] A small sample of (candidate) exoplanets exist with a temperature below 500 K, which could be spectroscopically confirmed as Y-dwarfs in the future. These exoplanets are Epsilon Indi Ab (275 K),[31] WD 1202–232b, WD 2105–82b (both low temperature),[32] GALEX J071816.4+373139b (400 K),[33] and WD 0310–688b (248+84
−61 K).[34]

Binaries

[edit]

Binaries consisting of a late T dwarf primary and a Y dwarf secondary are known since the discovery of CFBDS J1458+10 during the early discovery of Y-dwarfs.[9] Other such binaries are WISEPC J1217+1626[35] and WISE J0146+4234.[36] The first Y+Y binary is WISE J0336−0143, discovered in 2023 with JWST.[37]

Individual discoveries

[edit]
See also: List of Y-dwarfs

Timeline of Y-dwarf discoveries:

  • February 2011: Luhman et al. reported the discovery of WD 0806−661 B, a brown dwarf companion to a nearby white dwarf, with a temperature of c. 300 K (27 °C; 80 °F) and mass of 7 MJ.[29]
  • February 2011: Shortly after that, Liu et al. published an account of a "very cold" (c. 370 K (97 °C; 206 °F)) brown dwarf orbiting another very-low-mass brown dwarf and noted, "Given its low luminosity, atypical colors and cold temperature, CFBDS J1458+10B is a promising candidate for the hypothesized Y spectral class."[9]
  • August 2011: Scientists using data from NASA's Wide-field Infrared Survey Explorer (WISE) discovered six objects that they classified as Y dwarfs with temperatures as cool as 25 °C (298 K; 77 °F).[38][39] These were published in two papers.[1][2]
  • July 2012: Seven new Y-dwarfs were discovered, making the total number of confirmed Y-dwarfs fourteen.[40][41] One of the Y dwarfs, called WISE 1828+2650, was, as of August 2011, the record holder for the coldest brown dwarf—emitting no visible light at all, this type of object resembles a free-floating planet more than a star. WISE 1828+2650 was initially estimated to have an atmospheric temperature cooler than 300 K (27 °C; 80 °F).[42] Its temperature has since been revised, and newer estimates put it in the range of 250 to 400 K (−23 to 127 °C; −10 to 260 °F).[43]
  • November 2012: WISE J1639−6847 was discovered. As of February 2024, it was the second-closest known Y-dwarf to Earth.[44]
  • April 2014: WISE 0855−0714 was announced, with a temperature profile estimated around 225 to 260 K (−48 – −13 °C; −55–8 °F) and a mass of 3 to 10 MJ.[10] It was also unusual in that its observed parallax meant a distance close to 7.2 ± 0.7 light-years from the Solar System.
  • May 2015: Three Y-dwarfs were discovered with Hubble, bringing the total number of confirmed Y-dwarfs to 21.[49]
  • June 2018: WISEA J0302−5817 was published as a Y-dwarf, and WISEA J1141−3326 was confirmed as a Y-dwarf.[47]
  • August 2019: A search of the CatWISE catalog revealed CWISEP J1935-1546, one of the coldest brown dwarfs with an estimated temperature of 270 to 360 K (−3–87 °C; 26–188 °F).[50] In 2023 it was announced that CWISEP J1935-1546 had methane emission due to an aurora.[51]
  • February 2020: The CatWISE catalog combined NASA's WISE and NEOWISE surveys.[53] It expanded the number of faint sources and has therefore been used to find the faintest brown dwarfs, including Y dwarfs. Seventeen candidate Y dwarfs were discovered by the CatWISE researchers. Initial color with the Spitzer Space Telescope indicated that CW1446 is one of the reddest and coldest Y dwarfs.[54] Additional data with Spitzer showed that CW1446 is the fifth-reddest brown dwarf, with a temperature of about 310 to 360 K (37–87 °C; 98–188 °F) and a distance of about 10 parsecs.[55]
  • August 2020: Five candidate Y-dwarfs were discovered via the Backyard Worlds project.[56]
  • April 2021: New Y-dwarf candidates were published by the CatWISE and Backyard Worlds teams in a collaborative paper.[57]
  • August 2021: Ross 19B, an old object near the T/Y-boundary orbiting an M-dwarf, was discovered by the Backyard Worlds team.[30]
  • April 2023: WISE J0336−0143 was confirmed as a Y-dwarf binary with JWST.[58] The B secondary is likely one of the coldest confirmed Y-dwarfs as of December 2023, with an estimated temperature of 246 to 404 K (−27–131 °C; −17–268 °F).[59]
  • November 2023: CWISE J1055+5443, an object previously classified as a T-dwarf, was confirmed as a nearby Y-dwarf.[60]
  • December 2023: Three new Y-dwarf candidates were published.[59] The total number of confirmed Y-dwarfs was 27, and 30 additional Y-dwarf candidates existed as of February 2024.

References

[edit]
  1. ^ a b c d Kirkpatrick, J. Davy; Cushing, Michael C.; Gelino, Christopher R.; Griffith, Roger L.; Skrutskie, Michael F.; Marsh, Kenneth A.; Wright, Edward L.; Mainzer, A.; Eisenhardt, Peter R.; McLean, Ian S.; Thompson, Maggie A.; Bauer, James M.; Benford, Dominic J.; Bridge, Carrie R.; Lake, Sean E. (2011-12-01). "The First Hundred Brown Dwarfs Discovered by the Wide-field Infrared Survey Explorer (WISE)". The Astrophysical Journal Supplement Series. 197 (2): 19. arXiv:1108.4677. Bibcode:2011ApJS..197...19K. doi:10.1088/0067-0049/197/2/19. ISSN 0067-0049. S2CID 16850733.
  2. ^ a b c d Cushing, Michael C.; Kirkpatrick, J. Davy; Gelino, Christopher R.; Griffith, Roger L.; Skrutskie, Michael F.; Mainzer, A.; Marsh, Kenneth A.; Beichman, Charles A.; Burgasser, Adam J.; Prato, Lisa A.; Simcoe, Robert A.; Marley, Mark S.; Saumon, D.; Freedman, Richard S.; Eisenhardt, Peter R. (2011-12-01). "The Discovery of Y Dwarfs using Data from the Wide-field Infrared Survey Explorer (WISE)". The Astrophysical Journal. 743 (1): 50. arXiv:1108.4678. Bibcode:2011ApJ...743...50C. doi:10.1088/0004-637X/743/1/50. ISSN 0004-637X. S2CID 286881.
  3. ^ Coulter, Daniel J.; Barnes, Jason W.; Fortney, Jonathan J. (2022-11-01). "Jupiter and Saturn as Spectral Analogs for Extrasolar Gas Giants and Brown Dwarfs". The Astrophysical Journal Supplement Series. 263 (1): 15. arXiv:2208.05541. Bibcode:2022ApJS..263...15C. doi:10.3847/1538-4365/ac886a. ISSN 0067-0049.
  4. ^ Kirkpatrick, J. Davy; Reid, I. Neill; Liebert, James; Cutri, Roc M.; Nelson, Brant; Beichman, Charles A.; Dahn, Conard C.; Monet, David G.; Gizis, John E.; Skrutskie, Michael F. (1999-07-01). "Dwarfs Cooler than M: The Definition of Spectral Type L Using Discoveries from the 2 Micron All-Sky Survey (2MASS)". The Astrophysical Journal. 519 (2): 802–833. Bibcode:1999ApJ...519..802K. doi:10.1086/307414. ISSN 0004-637X.
  5. ^ a b Burrows, Adam; Sudarsky, David; Lunine, Jonathan I. (2003-10-01). "Beyond the T Dwarfs: Theoretical Spectra, Colors, and Detectability of the Coolest Brown Dwarfs". The Astrophysical Journal. 596 (1): 587–596. arXiv:astro-ph/0304226. Bibcode:2003ApJ...596..587B. doi:10.1086/377709. ISSN 0004-637X.
  6. ^ a b Sudarsky, David; Burrows, Adam; Hubeny, Ivan (2003-05-01). "Theoretical Spectra and Atmospheres of Extrasolar Giant Planets". The Astrophysical Journal. 588 (2): 1121–1148. arXiv:astro-ph/0210216. Bibcode:2003ApJ...588.1121S. doi:10.1086/374331. ISSN 0004-637X.
  7. ^ a b Eisenhardt, Peter R. M.; Griffith, Roger L.; Stern, Daniel; Wright, Edward L.; Ashby, Matthew L. N.; Brodwin, Mark; Brown, Michael J. I.; Bussmann, R. S.; Dey, Arjun; Ghez, Andrea Mia; Glikman, Eilat; Gonzalez, Anthony H.; Kirkpatrick, J. Davy; Konopacky, Quinn; Mainzer, Amy; Vollbach, David; Wright, Shelley A. (2010). "Ultracool Field Brown Dwarf Candidates Selected at 4.5 microns". The Astronomical Journal. 139 (6): 2455. arXiv:1004.1436. Bibcode:2010AJ....139.2455E. doi:10.1088/0004-6256/139/6/2455. S2CID 2019463.
  8. ^ a b Rodriguez, David R.; Zuckerman, Benjamin; Melis, Carl; Song, Inseok (10 May 2011). "The ultra cool brown dwarf companion of WD 0806-661B: age, mass, and formation mechanism". The Astrophysical Journal. 732 (2): L29. arXiv:1103.3544. Bibcode:2011ApJ...732L..29R. doi:10.1088/2041-8205/732/2/L29. S2CID 118382542.
  9. ^ a b c Liu, Michael C.; Delorme, Philippe; Dupuy, Trent J.; Bowler, Brendan P.; Albert, Loïc; Artigau, Étienne; Reylé, Céline; Forveille, Thierry; Delfosse, Xavier (28 Feb 2011). "CFBDSIR J1458+1013B: A Very Cold (>T10) Brown Dwarf in a Binary System". The Astrophysical Journal. 740 (2): 108. arXiv:1103.0014. Bibcode:2011ApJ...740..108L. doi:10.1088/0004-637X/740/2/108. S2CID 118344589.
  10. ^ a b Clavin, Whitney; Harrington, J. D. (25 April 2014). "NASA's Spitzer and WISE Telescopes Find Close, Cold Neighbor of Sun". NASA.gov. Archived from the original on 26 April 2014.
  11. ^ Luhman, K. L.; Tremblin, P.; et al. (January 2024). "JWST/NIRSpec Observations of the Coldest Known Brown Dwarf". The Astronomical Journal. 167 (1): 5. arXiv:2311.17316. Bibcode:2024AJ....167....5L. doi:10.3847/1538-3881/ad0b72. ISSN 0004-6256.
  12. ^ Beiler, Samuel A.; Cushing, Michael C.; Kirkpatrick, J. Davy; Schneider, Adam C.; Mukherjee, Sagnick; Marley, Mark S. (2023-07-01). "The First JWST Spectral Energy Distribution of a Y Dwarf". The Astrophysical Journal. 951 (2): L48. arXiv:2306.11807. Bibcode:2023ApJ...951L..48B. doi:10.3847/2041-8213/ace32c. ISSN 0004-637X.
  13. ^ a b c d Beiler, Samuel A.; Cushing, Michael C.; Kirkpatrick, J. Davy; Schneider, Adam C.; Mukherjee, Sagnick; Marley, Mark S.; Marocco, Federico; Smart, Richard L. (11 Jul 2024). "Precise Bolometric Luminosities and Effective Temperatures of 23 late-T and Y dwarfs Obtained with JWST". The Astrophysical Journal. 973 (2): 107. arXiv:2407.08518. Bibcode:2024ApJ...973..107B. doi:10.3847/1538-4357/ad6301.
  14. ^ Beiler, Samuel A.; Mukherjee, Sagnick; Cushing, Michael C.; Kirkpatrick, J. Davy; Schneider, Adam C.; Kothari, Harshil; Marley, Mark S.; Visscher, Channon (2024-09-01). "A Tale of Two Molecules: The Underprediction of CO2 and Overprediction of PH3 in Late T and Y Dwarf Atmospheric Models". The Astrophysical Journal. 973 (1): 60. arXiv:2407.15950. Bibcode:2024ApJ...973...60B. doi:10.3847/1538-4357/ad6759. ISSN 0004-637X.
  15. ^ a b c Zhijun, Tu; Shu, Wang; Liu, Jifeng (28 September 2024). "Physical Parameters and Properties of 20 Cold Brown Dwarfs in JWST". arXiv:2409.19191 [astro-ph].
  16. ^ Kothari, Harshil; Cushing, Michael C.; Burningham, Ben; Beiler, Samuel A.; Kirkpatrick, J. Davy; Schneider, Adam C.; Mukherjee, Sagnick; Marley, Mark S. (10 June 2024). "Probing the Heights and Depths of Y Dwarf Atmospheres: A Retrieval Analysis of the JWST Spectral Energy Distribution of WISE J035934.06−540154.6". arXiv:2406.06493 [astro-ph.SR].
  17. ^ Leggett, S. K.; Tremblin, Pascal (25 Sep 2023). "The First Y Dwarf Data From JWST Show That Dynamic and Diabatic Processes Regulate Cold Brown Dwarf Atmospheres". The Astrophysical Journal. 959 (2): 86. arXiv:2309.14567. Bibcode:2023ApJ...959...86L. doi:10.3847/1538-4357/acfdad.
  18. ^ Morley, Caroline V.; Fortney, Jonathan J.; Marley, Mark S.; Visscher, Channon; Saumon, Didier; Leggett, S. K. (2012-09-01). "Neglected Clouds in T and Y Dwarf Atmospheres". The Astrophysical Journal. 756 (2): 172. arXiv:1206.4313. Bibcode:2012ApJ...756..172M. doi:10.1088/0004-637X/756/2/172. ISSN 0004-637X. S2CID 118398946.
  19. ^ a b Leggett, S. K.; Cushing, Michael C.; Hardegree-Ullman, Kevin K.; Trucks, Jesica L.; Marley, M. S.; Morley, Caroline V.; Saumon, D.; Carey, S. J.; Fortney, J. J.; Gelino, C. R.; Gizis, J. E.; Kirkpatrick, J. D.; Mace, G. N. (2016-10-01). "Observed Variability at 1 and 4 μm in the Y0 Brown Dwarf WISEP J173835.52+273258.9". The Astrophysical Journal. 830 (2): 141. arXiv:1607.07888. Bibcode:2016ApJ...830..141L. doi:10.3847/0004-637X/830/2/141. ISSN 0004-637X.
  20. ^ Cushing, Michael C.; Hardegree-Ullman, Kevin K.; Trucks, Jesica L.; Morley, Caroline V.; Gizis, John E.; Marley, Mark S.; Fortney, Jonathan J.; Kirkpatrick, J. Davy; Gelino, Christopher R.; Mace, Gregory N.; Carey, Sean J. (2016-06-01). "The First Detection of Photometric Variability in a Y Dwarf: WISE J140518.39+553421.3". The Astrophysical Journal. 823 (2): 152. arXiv:1602.06321. Bibcode:2016ApJ...823..152C. doi:10.3847/0004-637X/823/2/152. ISSN 0004-637X.
  21. ^ Esplin, T. L.; Luhman, K. L.; Cushing, M. C.; Hardegree-Ullman, K. K.; Trucks, J. L.; Burgasser, A. J.; Schneider, A. C. (2016-11-01). "Photometric Monitoring of the Coldest Known Brown Dwarf with the Spitzer Space Telescope". The Astrophysical Journal. 832 (1): 58. arXiv:1609.05850. Bibcode:2016ApJ...832...58E. doi:10.3847/0004-637X/832/1/58. ISSN 0004-637X.
  22. ^ Schneider, Adam C.; Cushing, Michael C.; Kirkpatrick, J. Davy; Gelino, Christopher R.; Mace, Gregory N.; Wright, Edward L.; Eisenhardt, Peter R.; Skrutskie, M. F.; Griffith, Roger L.; Marsh, Kenneth A. (2015-05-01). "Hubble Space Telescope Spectroscopy of Brown Dwarfs Discovered with the Wide-field Infrared Survey Explorer". The Astrophysical Journal. 804 (2): 92. arXiv:1502.05365. Bibcode:2015ApJ...804...92S. doi:10.1088/0004-637X/804/2/92. ISSN 0004-637X.
  23. ^ Robbins, Grady; Meisner, Aaron M.; Schneider, Adam C.; Burgasser, Adam J.; Kirkpatrick, J. Davy; Gagné, Jonathan; Hsu, Chih-Chun; Moranta, Leslie; Casewell, Sarah; Marocco, Federico; Gerasimov, Roman; Faherty, Jacqueline K.; Kuchner, Marc J.; Caselden, Dan; Cushing, Michael C. (2023-11-01). "CWISE J105512.11+544328.3: A Nearby Y Dwarf Spectroscopically Confirmed with Keck/NIRES". The Astrophysical Journal. 958 (1): 94. arXiv:2310.09524. Bibcode:2023ApJ...958...94R. doi:10.3847/1538-4357/ad0043. ISSN 0004-637X.
  24. ^ Faherty, Jacqueline K.; Burningham, Ben; Gagné, Jonathan; Suárez, Genaro; Vos, Johanna M.; Alejandro Merchan, Sherelyn; Morley, Caroline V.; Rowland, Melanie; Lacy, Brianna; Kiman, Rocio; Caselden, Dan; Kirkpatrick, J. Davy; Meisner, Aaron; Schneider, Adam C.; Kuchner, Marc Jason; Bardalez Gagliuffi, Daniella Carolina; Beichman, Charles; Eisenhardt, Peter; Gelino, Christopher R.; Gharib-Nezhad, Ehsan; Gonzales, Eileen; Marocco, Federico; Rothermich, Austin James; Whiteford, Niall (2024-04-17). "Methane emission from a cool brown dwarf". Nature. 628 (8008): 511–514. arXiv:2404.10977. Bibcode:2024Natur.628..511F. doi:10.1038/s41586-024-07190-w. ISSN 1476-4687. PMC 11023930. PMID 38632480.
  25. ^ Kirkpatrick, J. Davy; Marocco, Federico; Caselden, Dan; Meisner, Aaron M.; Faherty, Jacqueline K.; Schneider, Adam C.; Kuchner, Marc J.; Casewell, S. L.; Gelino, Christopher R.; Cushing, Michael C.; Eisenhardt, Peter R.; Wright, Edward L.; Schurr, Steven D. (2021). "The Enigmatic Brown Dwarf WISEA J153429.75-104303.3 (A.k.a. "The Accident")". The Astrophysical Journal Letters. 915 (1): L6. arXiv:2106.13408. Bibcode:2021ApJ...915L...6K. doi:10.3847/2041-8213/ac0437. ISSN 2041-8205. S2CID 235651911.
  26. ^ Leggett, S. K.; Tremblin, P.; Esplin, T. L.; Luhman, K. L.; Morley, Caroline V. (2017-06-01). "The Y-type Brown Dwarfs: Estimates of Mass and Age from New Astrometry, Homogenized Photometry, and Near-infrared Spectroscopy". The Astrophysical Journal. 842 (2): 118. arXiv:1704.03573. Bibcode:2017ApJ...842..118L. doi:10.3847/1538-4357/aa6fb5. ISSN 0004-637X.
  27. ^ Fontanive, Clémence; Bedin, Luigi R.; De Furio, Matthew; Biller, Beth; Anderson, Jay; Bonavita, Mariangela; Allers, Katelyn; Pantoja, Blake (2023-12-01). "An HST survey of 33 T8 to Y1 brown dwarfs: NIR photometry and multiplicity of the coldest isolated objects". Monthly Notices of the Royal Astronomical Society. 526 (2): 1783–1798. arXiv:2309.09923. Bibcode:2023MNRAS.526.1783F. doi:10.1093/mnras/stad2870. ISSN 0035-8711.
  28. ^ Leggett, S. K.; Tremblin, Pascal (2024-01-01). "James Webb Space Telescope Spectra of Cold Brown Dwarfs are Well-reproduced by Phosphine-free, Diabatic, ATMO2020++ Models". Research Notes of the American Astronomical Society. 8 (1): 13. Bibcode:2024RNAAS...8...13L. doi:10.3847/2515-5172/ad1b61. ISSN 2515-5172.
  29. ^ a b Luhman, Kevin L.; Burgasser, Adam J.; Bochanski, John J. (20 March 2011). "Discovery of a candidate for the coolest known brown dwarf". The Astrophysical Journal Letters. 730 (1): L9. arXiv:1102.5411. Bibcode:2011ApJ...730L...9L. doi:10.1088/2041-8205/730/1/L9. S2CID 54666396.
  30. ^ a b Schneider, Adam C.; Meisner, Aaron M.; Gagné, Jonathan; Faherty, Jacqueline K.; Marocco, Federico; Burgasser, Adam J.; Kirkpatrick, J. Davy; Kuchner, Marc J.; Gramaize, Léopold; Rothermich, Austin; Brooks, Hunter; Vrba, Frederick J.; Bardalez Gagliuffi, Daniella; Caselden, Dan; Cushing, Michael C. (2021-11-01). "Ross 19B: An Extremely Cold Companion Discovered via the Backyard Worlds: Planet 9 Citizen Science Project". The Astrophysical Journal. 921 (2): 140. arXiv:2108.05321. Bibcode:2021ApJ...921..140S. doi:10.3847/1538-4357/ac1c75. ISSN 0004-637X.
  31. ^ Matthews, E. C.; Carter, A. L.; et al. (July 2024). "A temperate super-Jupiter imaged with JWST in the mid-infrared". Nature. 633 (8031): 789–792. doi:10.1038/s41586-024-07837-8. PMC 11424479. PMID 39048015.
  32. ^ Mullally, Susan E.; Debes, John; Cracraft, Misty; Mullally, Fergal; Poulsen, Sabrina; Albert, Loic; Thibault, Katherine; Reach, William T.; Hermes, J. J.; Barclay, Thomas; Kilic, Mukremin; Quintana, Elisa V. (24 Jan 2024). "JWST Directly Images Giant Planet Candidates Around Two Metal-Polluted White Dwarf Stars". The Astrophysical Journal Letters. 962 (2): L32. arXiv:2401.13153. Bibcode:2024ApJ...962L..32M. doi:10.3847/2041-8213/ad2348.
  33. ^ Cheng, Sihao; Schlaufman, Kevin C.; Caiazzo, Ilaria (2024-08-01). "A Candidate Giant Planet Companion to the Massive, Young White Dwarf GALEX J071816.4+373139 Informs the Occurrence of Giant Planets Orbiting B Stars". arXiv:2408.03985 [astro-ph.EP].
  34. ^ Limbach, Mary Anne; Vanderburg, Andrew; Venner, Alexander; Blouin, Simon; Stevenson, Kevin B.; MacDonald, Ryan J.; Jenkins, Sydney; Bowens-Rubin, Rachel; Soares-Furtado, Melinda (2024-08-29). "The MIRI Exoplanets Orbiting White Dwarfs (MEOW) Survey: Mid-Infrared Excess Reveals a Giant Planet Candidate around a Nearby White Dwarf". The Astrophysical Journal. 973 (1): L11. arXiv:2408.16813. Bibcode:2024ApJ...973L..11L. doi:10.3847/2041-8213/ad74ed.
  35. ^ Liu, Michael C.; Dupuy, Trent J.; Bowler, Brendan P.; Leggett, S. K.; Best, William M. J. (2012-10-01). "Two Extraordinary Substellar Binaries at the T/Y Transition and the Y-band Fluxes of the Coolest Brown Dwarfs". The Astrophysical Journal. 758 (1): 57. arXiv:1206.4044. Bibcode:2012ApJ...758...57L. doi:10.1088/0004-637X/758/1/57. ISSN 0004-637X. S2CID 118402490.
  36. ^ Dupuy, Trent J.; Liu, Michael C.; Leggett, S. K. (2015-04-01). "Discovery of a Low-luminosity, Tight Substellar Binary at the T/Y Transition". The Astrophysical Journal. 803 (2): 102. arXiv:1502.04707. Bibcode:2015ApJ...803..102D. doi:10.1088/0004-637X/803/2/102. hdl:2152/35100. ISSN 0004-637X. S2CID 118507808.
  37. ^ Calissendorff, Per; De Furio, Matthew; Meyer, Michael; Albert, Loïc; Aganze, Christian; Ali-Dib, Mohamad; Bardalez Gagliuffi, Daniella C.; Baron, Frederique; Beichman, Charles A.; Burgasser, Adam J.; Cushing, Michael C.; Faherty, Jacqueline Kelly; Fontanive, Clémence; Gelino, Christopher R.; Gizis, John E. (2023-04-01). "JWST/NIRCam Discovery of the First Y+Y Brown Dwarf Binary: WISE J033605.05-014350.4". The Astrophysical Journal. 947 (2): L30. arXiv:2303.16923. Bibcode:2023ApJ...947L..30C. doi:10.3847/2041-8213/acc86d. ISSN 0004-637X.
  38. ^ Plait, Phil (24 August 2011). "WISE finds coolest brown dwarfs ever seen!". Discover Magazine. Archived from the original on 26 July 2014. Retrieved 30 October 2013.
  39. ^ Clavin, Whitney (8 June 2012). "WISE Finds Few Brown Dwarfs Close To Home". NASA. Archived from the original on 15 March 2014. Retrieved 30 October 2013.
  40. ^ Kirkpatrick, J. Davy; Gelino, Christopher R.; Cushing, Michael C.; Mace, Gregory N.; Griffith, Roger L.; Skrutskie, Michael F.; Marsh, Kenneth A.; Wright, Edward L.; Eisenhardt, Peter R.; McLean, Ian S.; Mainzer, Amanda K.; Burgasser, Adam J.; Tinney, C. G.; Parker, Stephen; Salter, Graeme (2012-07-01). "Further Defining Spectral Type "Y" and Exploring the Low-mass End of the Field Brown Dwarf Mass Function". The Astrophysical Journal. 753 (2): 156. arXiv:1205.2122. Bibcode:2012ApJ...753..156K. doi:10.1088/0004-637X/753/2/156. ISSN 0004-637X.
  41. ^ Kirkpatrick, J. Davy; Burgasser, Adam J. (6 November 2012). "Photometry, spectroscopy, and astrometry of M, L, and T dwarfs". DwarfArchives.org. Pasadena, CA: California Institute of Technology. Retrieved 2012-12-28. (M=536, L=918, T=355, Y=14)
  42. ^ Morse, Jon. "Discovered: Stars as Cool as the Human Body". Archived from the original on 7 October 2011. Retrieved 24 August 2011.
  43. ^ Beichman, Charles A.; Gelino, Christopher R.; Kirkpatrick, J. Davy; Barman, Travis S.; Marsh, Kenneth A.; Cushing, Michael C.; Wright, Edward L. (2013). "The Coldest Brown Dwarf (or Free-floating Planet)?: The Y Dwarf WISE 1828+2650". The Astrophysical Journal. 764 (1): 101. arXiv:1301.1669. Bibcode:2013ApJ...764..101B. doi:10.1088/0004-637X/764/1/101. S2CID 118575478.
  44. ^ Tinney, C. G.; Faherty, Jacqueline K.; Kirkpatrick, J. Davy; Wright, Edward L.; Gelino, Christopher R.; Cushing, Michael C.; Griffith, Roger L.; Salter, Graeme (2012-11-01). "WISE J163940.83-684738.6: A Y Dwarf Identified by Methane Imaging". The Astrophysical Journal. 759 (1): 60. arXiv:1209.6123. Bibcode:2012ApJ...759...60T. doi:10.1088/0004-637X/759/1/60. ISSN 0004-637X.
  45. ^ Cushing, Michael C.; Kirkpatrick, J. Davy; Gelino, Christopher R.; Mace, Gregory N.; Skrutskie, Michael F.; Gould, Andrew (2014-05-01). "Three New Cool Brown Dwarfs Discovered with the Wide-field Infrared Survey Explorer (WISE) and an Improved Spectrum of the Y0 Dwarf WISE J041022.71+150248.4". The Astronomical Journal. 147 (5): 113. arXiv:1402.1378. Bibcode:2014AJ....147..113C. doi:10.1088/0004-6256/147/5/113. ISSN 0004-6256.
  46. ^ Tinney, C. G.; Faherty, Jacqueline K.; Kirkpatrick, J. Davy; Cushing, Mike; Morley, Caroline V.; Wright, Edward L. (2014-11-01). "The Luminosities of the Coldest Brown Dwarfs". The Astrophysical Journal. 796 (1): 39. arXiv:1410.0746. Bibcode:2014ApJ...796...39T. doi:10.1088/0004-637X/796/1/39. ISSN 0004-637X.
  47. ^ a b Tinney, C. G.; Kirkpatrick, J. Davy; Faherty, Jacqueline K.; Mace, Gregory N.; Cushing, Mike; Gelino, Christopher R.; Burgasser, Adam J.; Sheppard, Scott S.; Wright, Edward L. (2018-06-01). "New Y and T Dwarfs from WISE Identified by Methane Imaging". The Astrophysical Journal Supplement Series. 236 (2): 28. arXiv:1804.00362. Bibcode:2018ApJS..236...28T. doi:10.3847/1538-4365/aabad3. ISSN 0067-0049.
  48. ^ Dupuy, Trent J.; Liu, Michael C.; Leggett, S. K. (2015-04-01). "Discovery of a Low-luminosity, Tight Substellar Binary at the T/Y Transition". The Astrophysical Journal. 803 (2): 102. arXiv:1502.04707. Bibcode:2015ApJ...803..102D. doi:10.1088/0004-637X/803/2/102. hdl:2152/35100. ISSN 0004-637X. S2CID 118507808.
  49. ^ Schneider, Adam C.; Cushing, Michael C.; Kirkpatrick, J. Davy; Gelino, Christopher R.; Mace, Gregory N.; Wright, Edward L.; Eisenhardt, Peter R.; Skrutskie, M. F.; Griffith, Roger L.; Marsh, Kenneth A. (2015-05-01). "Hubble Space Telescope Spectroscopy of Brown Dwarfs Discovered with the Wide-field Infrared Survey Explorer". The Astrophysical Journal. 804 (2): 92. arXiv:1502.05365. Bibcode:2015ApJ...804...92S. doi:10.1088/0004-637X/804/2/92. ISSN 0004-637X.
  50. ^ Marocco, Federico; Caselden, Dan; Meisner, Aaron M.; Kirkpatrick, J. Davy; Wright, Edward L.; Faherty, Jacqueline K.; Gelino, Christopher R.; Eisenhardt, Peter R. M.; Fowler, John W.; Cushing, Michael C.; Cutri, Roc M.; Garcia, Nelson; Jarrett, Thomas H.; Koontz, Renata; Mainzer, Amanda; Marchese, Elijah J.; Mobasher, Bahram; Schlegel, David J.; Stern, Daniel; Teplitz, Harry I. (2019). "CWISEP J193518.59 − 154620.3: An Extremely Cold Brown Dwarf in the Solar Neighborhood Discovered with CatWISE". The Astrophysical Journal. 881 (1): 17. arXiv:1906.08913. Bibcode:2019ApJ...881...17M. doi:10.3847/1538-4357/ab2bf0. S2CID 195316522.
  51. ^ "NASA's Webb Finds Signs of Possible Aurorae on Isolated Brown Dwarf – NASA". 2024-01-09. Retrieved 2024-01-10.
  52. ^ Bardalez Gagliuffi, Daniella C.; Faherty, Jacqueline K.; Backyard Worlds: Planet 9 Citizen Science Collaboration; Schneider, Adam C.; Meisner, Aaron M.; Caselden, Dan; Colin, Guillaume; Goodman, Sam; Kirkpatrick, J. Davy; Kuchner, Marc J.; Gagne, Jonathan; Logsdon, Sarah E.; Burgasser, Adam J.; Allers, Katelyn N.; Debes, John H.; Wisniewski, John (January 2020). "WISE J0830+2837: the first Y dwarf from Backyard Worlds: Planet 9". AAS. 52: 132.06. Bibcode:2020AAS...23513206B.{{cite journal}}: CS1 maint: numeric names: authors list (link)
  53. ^ Eisenhardt, Peter R. M.; Marocco, Federico; Fowler, John W.; Meisner, Aaron M.; Kirkpatrick, J. Davy; Garcia, Nelson; Jarrett, Thomas H.; Koontz, Renata; Marchese, Elijah J.; Stanford, S. Adam; Caselden, Dan (2020). "The CatWISE Preliminary Catalog: Motions from WISE and NEOWISE Data". The Astrophysical Journal Supplement Series. 247 (2): 69. arXiv:1908.08902. Bibcode:2020ApJS..247...69E. doi:10.3847/1538-4365/ab7f2a. S2CID 201645245.
  54. ^ Meisner, Aaron M.; Caselden, Dan; Kirkpatrick, J. Davy; Marocco, Federico; Gelino, Christopher R.; Cushing, Michael C.; Eisenhardt, Peter R. M.; Wright, Edward L.; Faherty, Jacqueline K.; Koontz, Renata; Marchese, Elijah J. (2020). "Expanding the Y Dwarf Census with Spitzer Follow-up of the Coldest CatWISE Solar Neighborhood Discoveries". The Astrophysical Journal. 889 (2): 74. arXiv:1911.12372. Bibcode:2020ApJ...889...74M. doi:10.3847/1538-4357/ab6215. S2CID 208513044.
  55. ^ Marocco, Federico; Kirkpatrick, J. Davy; Meisner, Aaron M.; Caselden, Dan; Eisenhardt, Peter R. M.; Cushing, Michael C.; Faherty, Jacqueline K.; Gelino, Christopher R.; Wright, Edward L. (2020). "Improved infrared photometry and a preliminary parallax measurement for the extremely cold brown dwarf CWISEP J144606.62-231717.8". The Astrophysical Journal. 888 (2): L19. arXiv:1912.07692. Bibcode:2020ApJ...888L..19M. doi:10.3847/2041-8213/ab6201. S2CID 209386563.
  56. ^ Meisner, Aaron M.; Faherty, Jacqueline K.; Kirkpatrick, J. Davy; Schneider, Adam C.; Caselden, Dan; Gagné, Jonathan; Kuchner, Marc J.; Burgasser, Adam J.; Casewell, Sarah L.; Debes, John H.; Artigau, Étienne; Bardalez Gagliuffi, Daniella C.; Logsdon, Sarah E.; Kiman, Rocio; Allers, Katelyn (2020-08-01). "Spitzer Follow-up of Extremely Cold Brown Dwarfs Discovered by the Backyard Worlds: Planet 9 Citizen Science Project". The Astrophysical Journal. 899 (2): 123. arXiv:2008.06396. Bibcode:2020ApJ...899..123M. doi:10.3847/1538-4357/aba633. ISSN 0004-637X. S2CID 221135837.
  57. ^ Kirkpatrick, J. Davy; Gelino, Christopher R.; Faherty, Jacqueline K.; Meisner, Aaron M.; Caselden, Dan; Schneider, Adam C.; Marocco, Federico; Cayago, Alfred J.; Smart, R. L.; Eisenhardt, Peter R.; Kuchner, Marc J.; Wright, Edward L.; Cushing, Michael C.; Allers, Katelyn N.; Bardalez Gagliuffi, Daniella C. (2021-03-01). "The Field Substellar Mass Function Based on the Full-sky 20 pc Census of 525 L, T, and Y Dwarfs". The Astrophysical Journal Supplement Series. 253 (1): 7. arXiv:2011.11616. Bibcode:2021ApJS..253....7K. doi:10.3847/1538-4365/abd107. ISSN 0067-0049.
  58. ^ Calissendorff, Per; De Furio, Matthew; Meyer, Michael; Albert, Loïc; Aganze, Christian; Ali-Dib, Mohamad; Gagliuffi, Daniella C. Bardalez; Baron, Frederique; Beichman, Charles A.; Burgasser, Adam J.; Cushing, Michael C.; Faherty, Jacqueline Kelly; Fontanive, Clémence; Gelino, Christopher R.; Gizis, John E. (2023-03-29). "JWST/NIRCam Discovery of the First Y+Y Brown Dwarf Binary: WISE J033605.05–014350.4". The Astrophysical Journal Letters. 947 (2): L30. arXiv:2303.16923. Bibcode:2023ApJ...947L..30C. doi:10.3847/2041-8213/acc86d. S2CID 257833714.
  59. ^ a b Kirkpatrick, J. Davy; et al. (December 2023). "The Initial Mass Function Based on the Full-sky 20-pc Census of ∼3,600 Stars and Brown Dwarfs". The Astrophysical Journal Supplement Series. 271 (2): 55. arXiv:2312.03639. Bibcode:2024ApJS..271...55K. doi:10.3847/1538-4365/ad24e2.{{cite journal}}: CS1 maint: numeric names: authors list (link)
  60. ^ Robbins, Grady; Meisner, Aaron M.; Schneider, Adam C.; Burgasser, Adam J.; Kirkpatrick, J. Davy; Gagné, Jonathan; Hsu, Chih-Chun; Moranta, Leslie; Casewell, Sarah; Marocco, Federico; Gerasimov, Roman; Faherty, Jacqueline K.; Kuchner, Marc J.; Caselden, Dan; Cushing, Michael C. (2023-11-01). "CWISE J105512.11+544328.3: A Nearby Y Dwarf Spectroscopically Confirmed with Keck/NIRES". The Astrophysical Journal. 958 (1): 94. arXiv:2310.09524. Bibcode:2023ApJ...958...94R. doi:10.3847/1538-4357/ad0043. ISSN 0004-637X.
Retrieved from "https://en.wikipedia.org/w/index.php?title=Y_dwarf&oldid=1261453360"