Ultracool Objects: L, T, and Y Dwarfs

Part of the Astrophysics and Space Science Library book series (ASSL, volume 401)


The discovery of the first bona fide brown dwarfs in 1995 ushered in a new era in both stellar and planetary astrophysics. The emergent spectra of brown dwarfs are distinct from those of the lowest-mass stars and thus the creation of three new spectral classes, L, T, and Y, were required in order to classify them. In this chapter, I provide a historical review of the creation of these spectral classes and briefly discuss the physical conditions that give rise to the variations in spectral morphology used for classification.


Spectral Index Spectral Sequence Effective Temperature Spectral Type Vanadium Oxide 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.



I would like to thank Morag Hastie and J. Davy Kirkpatrick for providing useful comments on early versions of the manuscript and J. Davy Kirkpatrick and Adam Burgasser for ensuring the accuracy of the early history of the L and T dwarfs. The spectra shown in Figs. 24 were kindly provided by J. Davy Kirkpatrick, Adam Burgasser, and Sandy Leggett. This paper has benefitted from the SpeX Prism Spectral Libraries, maintained by Adam Burgasser at, and has made use of the NASA/ IPAC Infrared Science Archive, which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration. Finally I also would like to thank Viki Joergens for organizing the thoroughly enjoyable conference 50 Years of Brown Dwarfs: from Theoretical Prediction to Astrophysical Studies held at Ringberg Castle, Bavaria, Germany in October 2012.


  1. Ackerman, A.S., Marley, M.S.: Precipitating condensation clouds in substellar atmospheres. ApJ 556, 872–884 (2001)ADSCrossRefGoogle Scholar
  2. Adams, W.S., Joy, A.H., Humason, M.L.: The absolute magnitudes and parallaxes of 410 stars of type M. ApJ 64, 225–242 (1926)ADSCrossRefGoogle Scholar
  3. Allard, F., Hauschildt, P.H., Alexander, D.R., Starrfield, S.: Model atmospheres of very low mass stars and brown dwarfs. ARA&A 35, 137–177 (1997)ADSCrossRefGoogle Scholar
  4. Allard, F., Hauschildt, P.H., Alexander, D.R., Tamanai, A., Schweitzer, A.: The limiting effects of dust in brown dwarf model atmospheres. ApJ 556, 357–372 (2001)ADSCrossRefGoogle Scholar
  5. Allers, K.N., Jaffe, D.T., Luhman, K.L., Liu, M.C., Wilson, J.C., Skrutskie, M.F., Nelson, M., Peterson, D.E., Smith, J.D., Cushing, M.C.: Characterizing young brown dwarfs using low-resolution near-infrared spectra. ApJ 657, 511–520 (2007)ADSCrossRefGoogle Scholar
  6. Basri, G.: Observations of brown dwarfs. ARA&A 38, 485–519 (2000)ADSCrossRefGoogle Scholar
  7. Basri, G., Mohanty, S., Allard, F., Hauschildt, P.H., Delfosse, X., Martín, E.L., Forveille, T., Goldman, B.: An effective temperature scale for late-M and L dwarfs, from resonance absorption lines of Cs I and Rb I. ApJ 538, 363–385 (2000)ADSCrossRefGoogle Scholar
  8. Becklin, E.E., Zuckerman, B.: A low-temperature companion to a white dwarf star. Nature 336, 656–658 (1988)ADSCrossRefGoogle Scholar
  9. Bessell, M.S.: The late-M dwarfs. AJ 101, 662–676 (1991)ADSCrossRefGoogle Scholar
  10. Bochanski, J.J., Burgasser, A.J., Simcoe, R.A., West, A.A.: FIRE spectroscopy of the ultra-cool brown dwarf, UGPS J072227.51-054031.2: kinematics, rotation and atmospheric parameters. AJ 142, 169 (2011)Google Scholar
  11. Boeshaar, P.C.: The spectral classification of M-dwarf stars. PhD thesis, Ohio State University, Columbus (1976)Google Scholar
  12. Boeshaar, P.C., Tyson, J.A.: New limits on the surface density of M dwarfs. I – photographic survey and preliminary CCD data. AJ 90, 817–822 (1985)ADSCrossRefGoogle Scholar
  13. Burgasser, A.J., Kirkpatrick, J.D., Brown, M.E., Reid, I.N., Burrows, A., Liebert, J., Matthews, K., Gizis, J.E., Dahn, C.C., Monet, D.G., Cutri, R.M., Skrutskie, M.F.: The spectra of T dwarfs. I. Near-infrared data and spectral classification. ApJ 564, 421–451 (2002a)Google Scholar
  14. Burgasser, A.J., Marley, M.S., Ackerman, A.S., Saumon, D., Lodders, K., Dahn, C.C., Harris, H.C., Kirkpatrick, J.D.: Evidence of cloud disruption in the L/T dwarf transition. ApJ 571, L151–L154 (2002b)ADSCrossRefGoogle Scholar
  15. Burgasser, A.J., Kirkpatrick, J.D., Burrows, A., Liebert, J., Reid, I.N., Gizis, J.E., McGovern, M.R., Prato, L., McLean, I.S.: The first substellar subdwarf? Discovery of a metal-poor L dwarf with halo kinematics. ApJ 592, 1186–1192 (2003a)Google Scholar
  16. Burgasser, A.J., Kirkpatrick, J.D., Liebert, J., Burrows, A.: The spectra of T dwarfs. II. Red optical data. ApJ 594, 510–524 (2003b)Google Scholar
  17. Burgasser, A.J., Burrows, A., Kirkpatrick, J.D.: A method for determining the physical properties of the coldest known brown dwarfs. ApJ 639, 1095–1113 (2006a)ADSCrossRefGoogle Scholar
  18. Burgasser, A.J., Geballe, T.R., Leggett, S.K., Kirkpatrick, J.D., Golimowski, D.A.: A unified near-infrared spectral classification scheme for T dwarfs. ApJ 637, 1067–1093 (2006b)ADSCrossRefGoogle Scholar
  19. Burgasser, A.J., Tinney, C.G., Cushing, M.C., Saumon, D., Marley, M.S., Bennett, C.S., Kirkpatrick, J.D.: 2MASS J09393548-2448279: the coldest and least luminous brown dwarf binary known? ApJ 689, L53–L56 (2008)ADSCrossRefGoogle Scholar
  20. Burningham, B., Pinfield, D.J., Leggett, S.K., Tamura, M., Lucas, P.W., Homeier, D., Day-Jones, A., Jones, H.R.A., Clarke, J.R.A., Ishii, M., Kuzuhara, M., Lodieu, N., Zapatero Osorio, M.R., Venemans, B.P., Mortlock, D.J., Barrado y Navascués, D., Martín, E.L., Magazzù, A.: Exploring the substellar temperature regime down to ∼ 550K. MNRAS 391, 320–333 (2008)ADSCrossRefGoogle Scholar
  21. Burningham, B., Pinfield, D.J., Leggett, S.K., Tinney, C.G., Liu, M.C., Homeier, D., West, A.A., Day-Jones, A., Huelamo, N., Dupuy, T.J., Zhang, Z., Murray, D.N., Lodieu, N., Barrado y Navascués, D., Folkes, S., Galvez-Ortiz, M.C., Jones, H.R.A., Lucas, P.W., Calderon, M.M., Tamura, M.: The discovery of an M4+T8.5 binary system. MNRAS 395, 1237–1248 (2009)ADSCrossRefGoogle Scholar
  22. Burningham, B., Pinfield, D.J., Lucas, P.W., Leggett, S.K., Deacon, N.R., Tamura, M., Tinney, C.G., Lodieu, N., Zhang, Z.H., Huelamo, N., Jones, H.R.A., Murray, D.N., Mortlock, D.J., Patel, M., Barrado y Navascués, D., Zapatero Osorio, M.R., Ishii, M., Kuzuhara, M., Smart, R.L.: 47 new T dwarfs from the UKIDSS large area survey. MNRAS 406, 1885–1906 (2010)ADSGoogle Scholar
  23. Burningham, B., Lucas, P.W., Leggett, S.K., Smart, R., Baker, D., Pinfield, D.J., Tinney, C.G., Homeier, D., Allard, F., Zhang, Z.H., Gomes, J., Day-Jones, A.C., Jones, H.R.A., Kovács, G., Lodieu, N., Marocco, F., Murray, D.N., Sipőcz, B.: The discovery of the T8.5 dwarf UGPS J0521+3640. MNRAS 414, L90–L94 (2011)ADSCrossRefGoogle Scholar
  24. Burrows, A., Liebert, J.: The science of brown dwarfs. Rev. Mod. Phys. 65, 301–336 (1993)ADSCrossRefGoogle Scholar
  25. Burrows, A., Sharp, C.M.: Chemical equilibrium abundances in brown dwarf and extrasolar giant planet atmospheres. ApJ 512, 843–863 (1999)ADSCrossRefGoogle Scholar
  26. Burrows, A., Hubbard, W.B., Lunine, J.I., Liebert, J.: The theory of brown dwarfs and extrasolar giant planets. Rev. Mod. Phys. 73, 719–765 (2001)ADSCrossRefGoogle Scholar
  27. Burrows, A., Sudarsky, D., Lunine, J.I.: Beyond the T dwarfs: theoretical spectra, colors, and detectability of the coolest brown dwarfs. ApJ 596, 587–596 (2003)ADSCrossRefGoogle Scholar
  28. Cannon, A.J., Pickering, E.C.: Spectra of bright southern stars photographed with the 13-inch Boyden telescope as part of the Henry Draper Memorial. Ann. Harv. Coll. Obs. 28, 129 (1901)ADSGoogle Scholar
  29. Chabrier, G., Baraffe, I.: Theory of low-mass stars and substellar objects. ARA&A 38, 337–377 (2000)ADSCrossRefGoogle Scholar
  30. Cruz, K.L., Kirkpatrick, J.D., Burgasser, A.J.: Young L dwarfs identified in the field: a preliminary low-gravity, optical spectral sequence from L0 to L5. AJ 137, 3345–3357 (2009) http://0812.0364Google Scholar
  31. Cushing, M.C., Rayner, J.T., Vacca, W.D.: An infrared spectroscopic sequence of M, L, and T dwarfs. ApJ 623, 1115–1140 (2005)ADSCrossRefGoogle Scholar
  32. Cushing, M.C., Roellig, T.L., Marley, M.S., Saumon, D., Leggett, S.K., Kirkpatrick, J.D., Wilson, J.C., Sloan, G.C., Mainzer, A.K., Van Cleve, J.E., Houck, J.R.: A spitzer infrared spectrograph spectral sequence of M, L, and T dwarfs. ApJ 648, 614–628 (2006)ADSCrossRefGoogle Scholar
  33. Cushing, M.C., Marley, M.S., Saumon, D., Kelly, B.C., Vacca, W.D., Rayner, J.T., Freedman, R.S., Lodders, K., Roellig, T.L.: Atmospheric parameters of field L and T dwarfs. ApJ 678, 1372–1395 (2008)ADSCrossRefGoogle Scholar
  34. Cushing, M.C., Kirkpatrick, J.D., Gelino, C.R., Griffith, R.L., Skrutskie, M.F., Mainzer, A., Marsh, K.A., Beichman, C.A., Burgasser, A.J., Prato, L.A., Simcoe, R.A., Marley, M.S., Saumon, D., Freedman, R.S., Eisenhardt, P.R., Wright, E.L.: The discovery of Y dwarfs using data from the Wide-field Infrared Survey Explorer (WISE). ApJ 743, 50 (2011)ADSCrossRefGoogle Scholar
  35. Delfosse, X., Tinney, C.G., Forveille, T., Epchtein, N., Borsenberger, J., Fouqué, P., Kimeswenger, S., Tiphène, D.: Searching for very low-mass stars and brown dwarfs with DENIS. A&AS 135, 41–56 (1999)ADSCrossRefGoogle Scholar
  36. Delorme, P., Delfosse, X., Albert, L., Artigau, E., Forveille, T., Reylé, C., Allard, F., Homeier, D., Robin, A.C., Willott, C.J., Liu, M.C., Dupuy, T.J.: CFBDS J005910.90-011401.3: reaching the T-Y brown dwarf transition? A&A 482, 961–971 (2008a)ADSCrossRefGoogle Scholar
  37. Delorme, P., Willott, C.J., Forveille, T., Delfosse, X., Reylé, C., Bertin, E., Albert, L., Artigau, E., Robin, A.C., Allard, F., Doyon, R., Hill, G.J.: Finding ultracool brown dwarfs with MegaCam on CFHT: method and first results. A&A 484, 469–478 (2008b)ADSCrossRefGoogle Scholar
  38. Delorme, P., Albert, L., Forveille, T., Artigau, E., Delfosse, X., Reylé, C., Willott, C.J., Bertin, E., Wilkins, S.M., Allard, F., Arzoumanian, D.: Extending the Canada-France brown dwarfs survey to the near-infrared: first ultracool brown dwarfs from CFBDSIR. A&A 518, A39 (2010)ADSCrossRefGoogle Scholar
  39. Epchtein, N., de Batz, B., Capoani, L., Chevallier, L., Copet, E., Fouqué, P., Lacombe, P., Le Bertre, T., Pau, S., Rouan, D., Ruphy, S., Simon, G., Tiphène, D., Burton, W.B., Bertin, E., Deul, E., Habing, H., Borsenberger, J., Dennefeld, M., Guglielmo, F., Loup, C., Mamon, G., Ng, Y., Omont, A., Provost, L., Renault, J., Tanguy, F., Kimeswenger, S., Kienel, C., Garzon, F., Persi, P., Ferrari-Toniolo, M., Robin, A., Paturel, G., Vauglin, I., Forveille, T., Delfosse, X., Hron, J., Schultheis, M., Appenzeller, I., Wagner, S., Balazs, L., Holl, A., Lépine, J., Boscolo, P., Picazzio, E., Duc, P., Mennessier, M.: The deep near-infrared southern sky survey (DENIS). The Messenger 87, 27–34 (1997)ADSGoogle Scholar
  40. Evans, A., Geballe, T.R., Rushton, M.T., Smalley, B., van Loon, J.T., Eyres, S.P.S., Tyne, V.H.: V838 Mon: an L supergiant? MNRAS 343, 1054–1056 (2003)ADSCrossRefGoogle Scholar
  41. Geballe, T.R., Kulkarni, S.R., Woodward, C.E., Sloan, G.C.: The near-infrared spectrum of the brown dwarf Gliese 229B. ApJ 467, L101 (1996)ADSCrossRefGoogle Scholar
  42. Geballe, T.R., Knapp, G.R., Leggett, S.K., Fan, X., Golimowski, D.A., Anderson, S., Brinkmann, J., Csabai, I., Gunn, J.E., Hawley, S.L., Hennessy, G., Henry, T.J., Hill, G.J., Hindsley, R.B., Ivezić, Ž., Lupton, R.H., McDaniel, A., Munn, J.A., Narayanan, V.K., Peng, E., Pier, J.R., Rockosi, C.M., Schneider, D.P., Smith, J.A., Strauss, M.A., Tsvetanov, Z.I., Uomoto, A., York, D.G., Zheng, W.: Toward spectral classification of L and T dwarfs: infrared and optical spectroscopy and analysis. ApJ 564, 466–481 (2002)ADSCrossRefGoogle Scholar
  43. Golimowski, D.A., Leggett, S.K., Marley, M.S., Fan, X., Geballe, T.R., Knapp, G.R., Vrba, F.J., Henden, A.A., Luginbuhl, C.B., Guetter, H.H., Munn, J.A., Canzian, B., Zheng, W., Tsvetanov, Z.I., Chiu, K., Glazebrook, K., Hoversten, E.A., Schneider, D.P., Brinkmann, J.: L’ and M’ photometry of ultracool dwarfs. AJ 127, 3516–3536 (2004)ADSCrossRefGoogle Scholar
  44. Gorlova, N.I., Meyer, M.R., Rieke, G.H., Liebert, J.: Gravity indicators in the near-infrared spectra of brown dwarfs. ApJ 593, 1074–1092 (2003)ADSCrossRefGoogle Scholar
  45. Gray, R.O., Corbally, C.J.: Stellar Spectral Classification. Princeton University Press, Princeton/Woodstock (2009)Google Scholar
  46. Hanel, R., Conrath, B., Herath, L., Kunde, V., Pirraglia, J.: Albedo, internal heat, and energy balance of Jupiter – preliminary results of the Voyager infrared investigation. J. Geophys. Res. 86, 8705–8712 (1981)ADSCrossRefGoogle Scholar
  47. Hayashi, C., Nakano, T.: Evolution of stars of small masses in the pre-main-sequence stages. Prog. Theor. Phys. 30, 460–474 (1963)ADSCrossRefGoogle Scholar
  48. Jones, H.R.A., Tsuji, T.: Spectral evidence for dust in late-type M dwarfs. ApJ 480, L39 (1997)ADSCrossRefGoogle Scholar
  49. Joy, A.H.: Radial velocities and spectral types of 181 dwarf stars. ApJ 105, 96 (1947)ADSCrossRefGoogle Scholar
  50. Kimble, R.A., MacKenty, J.W., O’Connell, R.W., Townsend, J.A.: Wide Field Camera 3: a powerful new imager for the Hubble Space Telescope. In: Presented at the Society of Photo-Optical Instrumentation Engineers (SPIE) Conference, Marseille. Society of Photo-Optical Instrumentation Engineers (SPIE) Conference Series, vol. 7010 (2008)Google Scholar
  51. Kirkpatrick, J.D.: Spectroscopic properties of ultra-cool dwarfs and brown dwarf (invited review). In: Rebolo, R., Martín, E.L., Zapatero Osorio, M.R. (eds.) Brown Dwarfs and Extrasolar Planets. Astronomical Society of the Pacific Conference Series, vol. 134, p. 405. Astronomical Society of the Pacific, San Francisco (1998)Google Scholar
  52. Kirkpatrick, J.D.: New spectral types L and T. ARA&A 43, 195–245 (2005)ADSCrossRefGoogle Scholar
  53. Kirkpatrick, J.D.: Outstanding issues in our understanding of L, T, and Y dwarfs. In: van Belle, G. (ed.) 14th Cambridge Workshop on Cool Stars, Stellar Systems, and the Sun, Pasadena. Astronomical Society of the Pacific Conference Series, vol. 384, p. 85 (2008)Google Scholar
  54. Kirkpatrick, J.D., Henry, T.J., McCarthy, D.W., Jr.: A standard stellar spectral sequence in the red/near-infrared – Classes K5 to M9. ApJS 77, 417–440 (1991)ADSCrossRefGoogle Scholar
  55. Kirkpatrick, J.D., Henry, T.J., Liebert, J.: The unique spectrum of the brown dwarf candidate GD 165B and comparison to the spectra of other low-luminosity objects. ApJ 406, 701–707 (1993)ADSCrossRefGoogle Scholar
  56. Kirkpatrick, J.D., Allard, F., Bida, T., Zuckerman, B., Becklin, E.E., Chabrier, G., Baraffe, I.: An improved optical spectrum and new model FITS of the likely brown dwarf GD 165B. ApJ 519, 834–843 (1999a)ADSCrossRefGoogle Scholar
  57. Kirkpatrick, J.D., Reid, I.N., Liebert, J., Cutri, R.M., Nelson, B., Beichman, C.A., Dahn, C.C., Monet, D.G., Gizis, J.E., Skrutskie, M.F.: Dwarfs cooler than “M”: the definition of spectral type “L” using discoveries from the 2 Micron All-Sky Survey (2MASS). ApJ 519, 802–833 (1999b)ADSCrossRefGoogle Scholar
  58. Kirkpatrick, J.D., Barman, T.S., Burgasser, A.J., McGovern, M.R., McLean, I.S., Tinney, C.G., Lowrance, P.J.: Discovery of a very young field L dwarf, 2MASS J01415823-4633574. ApJ 639, 1120–1128 (2006)ADSCrossRefGoogle Scholar
  59. Kirkpatrick, J.D., Looper, D.L., Burgasser, A.J., Schurr, S.D., Cutri, R.M., Cushing, M.C., Cruz, K.L., Sweet, A.C., Knapp, G.R., Barman, T.S., Bochanski, J.J., Roellig, T.L., McLean, I.S., McGovern, M.R., Rice, E.L.: Discoveries from a near-infrared proper motion survey using multi-epoch Two Micron All-Sky survey data. ApJS 190, 100–146 (2010)ADSCrossRefGoogle Scholar
  60. Kirkpatrick, J.D., Cushing, M.C., Gelino, C.R., Griffith, R.L., Skrutskie, M.F., Marsh, K.A., Wright, E.L., Mainzer, A., Eisenhardt, P.R., McLean, I.S., Thompson, M.A., Bauer, J.M., Benford, D.J., Bridge, C.R., Lake, S.E., Petty, S.M., Stanford, S.A., Tsai, C.W., Bailey, V., Beichman, C.A., Bloom, J.S., Bochanski, J.J., Burgasser, A.J., Capak, P.L., Cruz, K.L., Hinz, P.M., Kartaltepe, J.S., Knox, R.P., Manohar, S., Masters, D., Morales-Calderón, M., Prato, L.A., Rodigas, T.J., Salvato, M., Schurr, S.D., Scoville, N.Z., Simcoe, R.A., Stapelfeldt, K.R., Stern, D., Stock, N.D., Vacca, W.D.: The first hundred brown dwarfs discovered by the Wide-field Infrared Survey Explorer (WISE). ApJS 197, 19 (2011)ADSCrossRefGoogle Scholar
  61. Kirkpatrick, J.D., Gelino, C.R., Cushing, M.C., Mace, G.N., Griffith, R.L., Skrutskie, M.F., Marsh, K.A., Wright, E.L., Eisenhardt, P.R., McLean, I.S., Mainzer, A.K., Burgasser, A.J., Tinney, C.G., Parker, S., Salter, G.: Further defining spectral type “Y” and exploring the low-mass end of the field brown dwarf mass function. ApJ 753, 156 (2012)ADSCrossRefGoogle Scholar
  62. Knapp, G.R., Leggett, S.K., Fan, X., Marley, M.S., Geballe, T.R., Golimowski, D.A., Finkbeiner, D., Gunn, J.E., Hennawi, J., Ivezić, Z., Lupton, R.H., Schlegel, D.J., Strauss, M.A., Tsvetanov, Z.I., Chiu, K., Hoversten, E.A., Glazebrook, K., Zheng, W., Hendrickson, M., Williams, C.C., Uomoto, A., Vrba, F.J., Henden, A.A., Luginbuhl, C.B., Guetter, H.H., Munn, J.A., Canzian, B., Schneider, D.P., Brinkmann, J.: Near-infrared photometry and spectroscopy of L and T dwarfs: the effects of temperature, clouds, and gravity. AJ 127, 3553–3578 (2004)ADSCrossRefGoogle Scholar
  63. Kuiper, G.P.: The nearest stars. ApJ 95, 201 (1942)ADSCrossRefGoogle Scholar
  64. Kumar, S.S.: The structure of stars of very low mass. ApJ 137, 1121 (1963)ADSCrossRefGoogle Scholar
  65. Lawrence, A., Warren, S.J., Almaini, O., Edge, A.C., Hambly, N.C., Jameson, R.F., Lucas, P., Casali, M., Adamson, A., Dye, S., Emerson, J.P., Foucaud, S., Hewett, P., Hirst, P., Hodgkin, S.T., Irwin, M.J., Lodieu, N., McMahon, R.G., Simpson, C., Smail, I., Mortlock, D., Folger, M.: The UKIRT Infrared Deep Sky Survey (UKIDSS). MNRAS 379, 1599–1617 (2007)ADSCrossRefGoogle Scholar
  66. Leggett, S.K., Marley, M.S., Freedman, R., Saumon, D., Liu, M.C., Geballe, T.R., Golimowski, D.A., Stephens, D.C.: Physical and spectral characteristics of the T8 and later type dwarfs. ApJ 667, 537–548 (2007)ADSCrossRefGoogle Scholar
  67. Leggett, S.K., Cushing, M.C., Saumon, D., Marley, M.S., Roellig, T.L., Warren, S.J., Burningham, B., Jones, H.R.A., Kirkpatrick, J.D., Lodieu, N., Lucas, P.W., Mainzer, A.K., Martín, E.L., McCaughrean, M.J., Pinfield, D.J., Sloan, G.C., Smart, R.L., Tamura, M., Van Cleve, J.: The physical properties of four 600 K T dwarfs. ApJ 695, 1517–1526 (2009)ADSCrossRefGoogle Scholar
  68. Leggett, S.K., Saumon, D., Marley, M.S., Lodders, K., Canty, J., Lucas, P., Smart, R.L., Tinney, C.G., Homeier, D., Allard, F., Burningham, B., Day-Jones, A., Fegley, B., Ishii, M., Jones, H.R.A., Marocco, F., Pinfield, D.J., Tamura, M.: The properties of the 500 K dwarf UGPS J072227.51-054031.2 and a study of the far-red flux of cold brown dwarfs. ApJ 748, 74 (2012)Google Scholar
  69. Leggett, S.K., Morley, C.V., Marley, M.S., Saumon, D., Fortney, J.J., Visscher, C.: A comparison of near-infrared photometry and spectra for Y dwarfs with a new generation of cool cloudy models. ApJ 763, 130 (2013)ADSCrossRefGoogle Scholar
  70. Linsky, J.L.: On the pressure-induced opacity of molecular hydrogen in late-type stars. ApJ 156, 989 (1969)ADSCrossRefGoogle Scholar
  71. Liu, M.C., Delorme, P., Dupuy, T.J., Bowler, B.P., Albert, L., Artigau, E., Reylé, C., Forveille, T., Delfosse, X.: CFBDSIR J1458+1013B: a very cold ( > T10) brown dwarf in a binary system. ApJ 740, 108 (2011)ADSCrossRefGoogle Scholar
  72. Lodders, K.: Alkali element chemistry in cool dwarf atmospheres. ApJ 519, 793–801 (1999)ADSCrossRefGoogle Scholar
  73. Lucas, P.W., Tinney, C.G., Burningham, B., Leggett, S.K., Pinfield, D.J., Smart, R., Jones, H.R.A., Marocco, F., Barber, R.J., Yurchenko, S.N., Tennyson, J., Ishii, M., Tamura, M., Day-Jones,s A.C., Adamson, A., Allard, F., Homeier, D.: The discovery of a very cool, very nearby brown dwarf in the Galactic plane. MNRAS 408, L56–L60 (2010) http://1004.0317Google Scholar
  74. Luhman, K.L., Burgasser, A.J., Bochanski, J.J.: Discovery of a candidate for the coolest known brown dwarf. ApJ 730, L9 (2011)ADSCrossRefGoogle Scholar
  75. Luhman, K.L., Burgasser, A.J., Labbé, I., Saumon, D., Marley, M.S., Bochanski, J.J., Monson, A.J., Persson, S.E.: Confirmation of one of the coldest known brown dwarfs. ApJ 744, 135 (2012)ADSCrossRefGoogle Scholar
  76. Martín, E.L., Basri, G., Delfosse, X., Forveille, T.: Keck HIRES spectra of the brown dwarf DENIS-P J1228.2-1547. A&A 327, L29–L32 (1997)ADSGoogle Scholar
  77. Martín, E.L., Delfosse, X., Basri, G., Goldman, B., Forveille, T., Zapatero Osorio, M.R.: Spectroscopic classification of late-M and L field dwarfs. AJ 118, 2466–2482 (1999)ADSCrossRefGoogle Scholar
  78. McLean, I.S., Prato, L., Kim, S.S., Wilcox, M.K., Kirkpatrick, J.D., Burgasser, A.: Near-infrared spectroscopy of brown dwarfs: methane and the transition between the L and T spectral types. ApJ 561, L115–L118 (2001)ADSCrossRefGoogle Scholar
  79. McLean, I.S., McGovern, M.R., Burgasser, A.J., Kirkpatrick, J.D., Prato, L., Kim, S.S.: The NIRSPEC brown dwarf spectroscopic survey. I. Low-resolution near-infrared spectra. ApJ 596, 561–586 (2003)Google Scholar
  80. Morgan, W.W.: On the spectral types and luminosities of the M dwarfs. ApJ 87, 589 (1938)ADSCrossRefGoogle Scholar
  81. Morgan, W.W.: The MK system and the MK process. In: Garrison, R.F. (ed.) The MK Process and Stellar Classification, p. 18. David Dunlap Observatory, University of Toronto, Toronto (1984)Google Scholar
  82. Morgan, W.W., Keenan, P.C., Kellman, E.: An atlas of stellar spectra, with an outline of spectral classification. The University of Chicago Press, Chicago (1943)Google Scholar
  83. Morley, C.V., Fortney, J.J., Marley, M.S., Visscher, C., Saumon, D., Leggett, S.K.: Neglected clouds in T and Y dwarf atmospheres. ApJ 756, 172 (2012)ADSCrossRefGoogle Scholar
  84. Nakajima, T., Oppenheimer, B.R., Kulkarni, S.R., Golimowski, D.A., Matthews, K., Durrance, S.T.: Discovery of a cool brown dwarf. Nature 378, 463–465 (1995)ADSCrossRefGoogle Scholar
  85. Oppenheimer, B.R., Kulkarni, S.R., Matthews, K., Nakajima, T.: Infrared spectrum of the cool brown dwarf Gl 229B. Science 270, 1478–1479 (1995)ADSCrossRefGoogle Scholar
  86. Oppenheimer, B.R., Kulkarni, S.R., Matthews, K., van Kerkwijk, M.H.: The spectrum of the brown dwarf Gliese 229B. ApJ 502, 932 (1998)ADSCrossRefGoogle Scholar
  87. Pickering, E.C.: The Draper catalogue of stellar spectra photographed with the 8-inch Bache telescope as a part of the Henry Draper memorial. Ann. Harv. Coll. Obs. 27, 1–388 (1890)ADSGoogle Scholar
  88. Reid, I.N., Kirkpatrick, J.D., Gizis, J.E., Liebert, J.: BRI 0021-0214: another surprise at the bottom of the main sequence. ApJ 527, L105–L107 (1999)ADSCrossRefGoogle Scholar
  89. Reid, I.N., Burgasser, A.J., Cruz, K.L., Kirkpatrick, J.D., Gizis, J.E.: Near-infrared spectral classification of late M and L dwarfs. AJ 121, 1710–1721 (2001)ADSCrossRefGoogle Scholar
  90. Saumon, D., Marley, M.S., Cushing, M.C., Leggett, S.K., Roellig, T.L., Lodders, K., Freedman, R.S.: Ammonia as a tracer of chemical equilibrium in the T7.5 dwarf Gliese 570D. ApJ 647, 552–557 (2006)ADSCrossRefGoogle Scholar
  91. Saumon, D., Marley, M.S., Leggett, S.K., Geballe, T.R., Stephens, D., Golimowski, D.A., Cushing, M.C., Fan, X., Rayner, J.T., Lodders, K., Freedman, R.S.: Physical parameters of two very cool T dwarfs. ApJ 656, 1136–1149 (2007)ADSCrossRefGoogle Scholar
  92. Saumon, D., Marley, M.S., Abel, M., Frommhold, L., Freedman, R.S.: New H2 collision-induced absorption and NH3 opacity and the spectra of the coolest brown dwarfs. ApJ 750, 74 (2012)ADSCrossRefGoogle Scholar
  93. Skrutskie, M.F., Cutri, R.M., Stiening, R., Weinberg, M.D., Schneider, S., Carpenter, J.M., Beichman, C., Capps, R., Chester, T., Elias, J., Huchra, J., Liebert, J., Lonsdale, C., Monet, D.G., Price, S., Seitzer, P., Jarrett, T., Kirkpatrick, J.D., Gizis, J.E., Howard, E., Evans, T., Fowler, J., Fullmer, L., Hurt, R., Light, R., Kopan, E.L., Marsh, K.A., McCallon, H.L., Tam, R., Van Dyk, S., Wheelock, S.: The Two Micron All Sky Survey (2MASS). AJ 131, 1163–1183 (2006)ADSCrossRefGoogle Scholar
  94. Stephens, D.C., Leggett, S.K., Cushing, M.C., Marley, M.S., Saumon, D., Geballe, T.R., Golimowski, D.A., Fan, X., Noll, K.S.: The 0.8–14.5 μm spectra of mid-L to mid-T dwarfs: diagnostics of effective temperature, grain sedimentation, gas transport, and surface gravity. ApJ 702, 154–170 (2009)ADSCrossRefGoogle Scholar
  95. Stevenson, D.J.: The search for brown dwarfs. ARA&A 29, 163–193 (1991)ADSCrossRefGoogle Scholar
  96. Testi, L.: A low-resolution near-infrared spectral library of M-, L-, and T-dwarfs. A&A 503, 639–650 (2009)ADSCrossRefGoogle Scholar
  97. Tinney, C.G., Faherty, J.K., Kirkpatrick, J.D., Wright, E.L., Gelino, C.R., Cushing, M.C., Griffith, R.L., Salter, G.: WISE J163940.83-684738.6: A Y dwarf identified by methane imaging. ApJ 759, 60 (2012)Google Scholar
  98. Tokunaga, A.T., Kobayashi, N.: K-band spectra and narrowband photometry of DENIS field brown dwarfs. AJ 117, 1010–1013 (1999)ADSCrossRefGoogle Scholar
  99. Tokunaga, A.T., Brooke, T.Y., Becklin, E.E., Zuckerman, B.: The infrared spectra of possible brown dwarf companions to G29-38 and GD 165A. Bull. Am. Astron. Soc. 22, 1078 (1990)ADSGoogle Scholar
  100. Vrba, F.J., Henden, A.A., Luginbuhl, C.B., Guetter, H.H., Munn, J.A., Canzian, B., Burgasser, A.J., Kirkpatrick, J.D., Fan, X., Geballe, T.R., Golimowski, D.A., Knapp, G.R., Leggett, S.K., Schneider, D.P., Brinkmann, J.: Preliminary parallaxes of 40 L and T dwarfs from the US Naval Observatory Infrared Astrometry Program. AJ 127, 2948–2968 (2004)ADSCrossRefGoogle Scholar
  101. Warren, S.J., Mortlock, D.J., Leggett, S.K., Pinfield, D.J., Homeier, D., Dye, S., Jameson, R.F., Lodieu, N., Lucas, P.W., Adamson, A.J., Allard, F., Barrado y Navascués, D., Casali, M., Chiu, K., Hambly, N.C., Hewett, P.C., Hirst, P., Irwin, M.J., Lawrence, A., Liu, M.C., Martín, E.L., Smart, R.L., Valdivielso, L., Venemans, B.P.: A very cool brown dwarf in UKIDSS DR1. MNRAS 381, 1400–1412 (2007)ADSCrossRefGoogle Scholar
  102. Witte, S., Helling, C., Barman, T., Heidrich, N., Hauschildt, P.H.: Dust in brown dwarfs and extra-solar planets. III. Testing synthetic spectra on observations. A&A 529, A44 (2011)Google Scholar
  103. Wright, E.L., Eisenhardt, P.R.M., Mainzer, A.K., Ressler, M.E., Cutri, R.M., Jarrett, T., Kirkpatrick, J.D., Padgett, D., McMillan, R.S., Skrutskie, M., Stanford, S.A., Cohen, M., Walker, R.G., Mather, J.C., Leisawitz, D., Gautier, T.N., McLean, I., Benford, D., Lonsdale, C.J., Blain, A., Mendez, B., Irace, W.R., Duval, V., Liu, F., Royer, D., Heinrichsen, I., Howard, J., Shannon, M., Kendall, M., Walsh, A.L., Larsen, M., Cardon, J.G., Schick, S., Schwalm, M., Abid, M., Fabinsky, B., Naes, L., Tsai, C.: The Wide-field Infrared Survey Explorer (WISE): mission description and initial on-orbit performance. AJ 140, 1868–1881 (2010)Google Scholar
  104. York, D.G., Adelman, J., Anderson, J.E., Jr., Anderson, S.F., Annis, J., Bahcall, N.A., Bakken, J.A., Barkhouser, R., Bastian, S., Berman, E., Boroski, W.N., Bracker, S., Briegel, C., Briggs, J.W., Brinkmann, J., Brunner, R., Burles, S., Carey, L., Carr, M.A., Castander, F.J., Chen, B., Colestock, P.L., Connolly, A.J., Crocker, J.H., Csabai, I., Czarapata, P.C., Davis, J.E., Doi, M., Dombeck, T., Eisenstein, D., Ellman, N., Elms, B.R., Evans, M.L., Fan, X., Federwitz, G.R., Fiscelli, L., Friedman, S., Frieman, J.A., Fukugita, M., Gillespie, B., Gunn, J.E., Gurbani, V.K., de Haas, E., Haldeman, M., Harris, F.H., Hayes, J., Heckman, T.M., Hennessy, G.S., Hindsley, R.B., Holm, S., Holmgren, D.J., Huang, C., Hull, C., Husby, D., Ichikawa, S., Ichikawa, T., Ivezić, Ž., Kent, S., Kim, R.S.J., Kinney, E., Klaene, M., Kleinman, A.N., Kleinman, S., Knapp, G.R., Korienek, J., Kron, R.G., Kunszt, P.Z., Lamb, D.Q., Lee, B., Leger, R.F., Limmongkol, S., Lindenmeyer, C., Long, D.C., Loomis, C., Loveday, J., Lucinio, R., Lupton, R.H., MacKinnon, B., Mannery, E.J., Mantsch, P.M., Margon, B., McGehee, P., McKay, T.A., Meiksin, A., Merelli, A., Monet, D.G., Munn, J.A., Narayanan, V.K., Nash, T., Neilsen, E., Neswold, R., Newberg, H.J., Nichol, R.C., Nicinski, T., Nonino, M., Okada, N., Okamura, S., Ostriker, J.P., Owen, R., Pauls, A.G., Peoples, J., Peterson, R.L., Petravick, D., Pier, J.R., Pope, A., Pordes, R., Prosapio, A., Rechenmacher, R., Quinn, T.R., Richards, G.T., Richmond, M.W., Rivetta, C.H., Rockosi, C.M., Ruthmansdorfer, K., Sandford, D., Schlegel, D.J., Schneider, D.P., Sekiguchi, M., Sergey, G., Shimasaku, K., Siegmund, W.A., Smee, S., Smith, J.A., Snedden, S., Stone, R., Stoughton, C., Strauss, M.A., Stubbs, C., SubbaRao, M., Szalay, A.S., Szapudi, I., Szokoly, G.P., Thakar, A.R., Tremonti, C., Tucker, D.L., Uomoto, A., Vanden Berk, D., Vogeley, M.S., Waddell, P., Wang, S., Watanabe, M., Weinberg, D.H., Yanny, B., Yasuda, N.: The Sloan Digital Sky Survey: technical summary. AJ 120, 1579–1587 (2000)Google Scholar

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© Springer International Publishing Switzerland 2014

Authors and Affiliations

  1. 1.Department of Physics and AstronomyUniversity of ToledoToledoUSA

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