UGPS J072227.51-054031.2

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UGPS J072227.51-054031.2
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Monoceros
Right ascension 07h 22m 27.29s[1]
Declination −05° 40′ 30.0″[2]
Spectral type T9[2]
Apparent magnitude (i (AB SDSS)) 24.32 ± 0.12[3]
Apparent magnitude (z) 20.51 ± 0.09[1][4]
Apparent magnitude (Y) 17.37 ± 0.02[1]
Apparent magnitude (J) 16.52 ± 0.02[1]
Apparent magnitude (H) 16.90 ± 0.02[1]
Apparent magnitude (K) 17.07 ± 0.08[1]
Apparent magnitude (L') 13.4 ± 0.3[1]
Apparent magnitude (N) 10.28 ± 0.24[1]
Radial velocity (Rv) 46.9 ± 2.5[4] km/s
Proper motion (μ) RA: −904.14 ± 1.71[3] mas/yr
Dec.: 352.025 ± 1.21[3] mas/yr
Parallax (π) 242.8 ± 2.4[3] mas
Distance 13.4 ± 0.1 ly
(4.12 ± 0.04 pc)
Mass (10.7 ± 0.2)—(25.8 ± 0.9)[5] MJup
Radius (0.886 ± 0.005)—(1.0192 ± 0.0005)[5] RJup
Luminosity (bolometric) (6.3 ± 0.4×10−7[5] L
Surface gravity (log g) (4.39 ± 0.01)—(4.90 ± 0.01)[5] cgs
Temperature (502 ± 10)—(539 ± 12)[5] K
Rotational velocity (v sin i) 40 ± 10[4] km/s
Age 1–5[4] Gyr
Other designations
WISEPA J072227.27-054029.9[6]
Database references

UGPS J072227.51-054031.2 (designation often abbreviated to UGPS 0722-05) is a brown dwarf of late T type, located approximately 4.1 parsecs (13 light-years) from Earth.[3]

History of observations[edit]


The astronomical object was discovered by Philip Lucas at the University of Hertfordshire and announced in 2010. The discovery image was taken on 28 November 2006 by the UKIRT Infrared Deep Sky Survey (UKIDSS) with a recovery image confirming the object's proper motion on 2 March 2010.[1] The reported distance is derived from the current measured parallax of 246 milliarcseconds. The object was initially reported to be at an even closer distance of 2.9 parsecs, which would have placed it among the ten nearest stars to the Sun[7] but later measurements revealed that the object was in fact located at a greater distance than initially thought, at 4.1+0.6

Adaptive optics observations[edit]

In 2010 Bouy et al. observed UGPS 0722-05 using adaptive optics at the Very Large Telescope. Any companion with H magnitude ≲ 19.4 at separations larger than 50 mas, or with H magnitude ≲ 21.4 at separations larger than 100 mas was not detected.[8]

Assignment of spectral class[edit]

In 2010 Lucas et al. provisionally assigned to UGPS 0722-05 spectral class T10 and suggested that it may be the first example of a new spectral class.[1]

In 2011 paper Cushing et al. established a boundary between spectral class T and new spectral class Y—a feature of spectrum, associated with NH3, and introduced spectral standards at the T/Y transition—for classes T9 and Y0. UGPS 0722-05 was reclassified to T9, and was declared the T9 spectral standard.[2]


Currently the most accurate distance estimate of UGPS 0722-05 is a trigonometric parallax, published in 2013 by Leggett et al.: 0.2428 ± 0.0024 arcsecond, corresponding to a distance 4.12 ± 0.04 pc, or 13.43 ± 0.13 ly.[3]

Space motion[edit]

UGPS 0722-05 has proper motion of about 970 milliarcseconds per year.[3]

Radial velocity of UGPS 0722-05, measured by Bochanski et al. and published in 2011, is 46.9 ± 2.5 km/s.[4][~ 1]


The object is roughly the volume of Jupiter, but is estimated to have 5–40 Jupiter masses (MJ).[1] This would make it less massive than ε Indi Ba. Planets have a mass of less than about 13 Jupiter masses. Infrared spectra shows the object contains water vapor and methane and has a surface temperature of approximately 480–560 Kelvin.[1]


  1. ^ Positive value of radial velocity indicates that UGPS 0722-05 currently moves away from us. A significant excess of radial velocity (46.9 km/s) over tangential velocity (19 km/s) indicates that UGPS 0722-05 was much closer to us in past (assuming proper motion and parallax from Leggett et al. (2012), minimal distance from Solar system to UGPS 0722-05 was 5.0 ly about 72000 BC, and probably it was one of the nearest Solar neighbours at the time).


  1. ^ a b c d e f g h i j k l m Lucas, P. W.; Tinney, C. G.; Burningham, B.; Leggett, S. K.; Pinfield, D. J.; et al. (2010). "The discovery of a very cool, very nearby brown dwarf in the Galactic plane". Monthly Notices of the Royal Astronomical Society. 408 (1): L56–L60. arXiv:1004.0317Freely accessible. Bibcode:2010MNRAS.408L..56L. doi:10.1111/j.1745-3933.2010.00927.x. 
  2. ^ a b c 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.; Wright, Edward L. (2011). "The Discovery of Y Dwarfs using Data from the Wide-field Infrared Survey Explorer (WISE)". The Astrophysical Journal. 743 (1): 50. arXiv:1108.4678Freely accessible. Bibcode:2011ApJ...743...50C. doi:10.1088/0004-637X/743/1/50. 
  3. ^ a b c d e f g 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, Ben; Day-Jones, A.; Fegley, B.; Ishii, Miki; Jones, H. R. A.; Marocco, F.; Pinfield, D. J.; Tamura, M. (2012). "The Properties of the 500 K Dwarf UGPS J072227.51-054031.2 and a Study of the Far-red Flux of Cold Brown Dwarfs". The Astrophysical Journal. 748 (2): 74. arXiv:1201.2973Freely accessible. Bibcode:2012ApJ...748...74L. doi:10.1088/0004-637X/748/2/74. 
  4. ^ a b c d e Bochanski, John J.; Burgasser, Adam J.; Simcoe, Robert A.; West, Andrew A. (2011). "FIRE Spectroscopy of the Ultra-cool Brown Dwarf, UGPS J072227.51-054031.2: Kinematics, Rotation and Atmospheric Parameters". The Astronomical Journal. 142 (5): 169. arXiv:1109.2897Freely accessible. Bibcode:2011AJ....142..169B. doi:10.1088/0004-6256/142/5/169. 
  5. ^ a b c d e Dupuy, T. J.; Kraus, A. L. (2013). "Distances, Luminosities, and Temperatures of the Coldest Known Substellar Objects". Science. 341 (6153): 1492–5. arXiv:1309.1422Freely accessible. Bibcode:2013Sci...341.1492D. doi:10.1126/science.1241917. PMID 24009359. 
  6. ^ 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.; Petty, Sara M.; Stanford, S. A.; Tsai, Chao-Wei; Bailey, Vanessa; Beichman, Charles A.; Bloom, Joshua S.; Bochanski, John J.; Burgasser, Adam J.; Capak, Peter L.; Cruz, Kelle L.; Hinz, Philip M.; Kartaltepe, Jeyhan S.; Knox, Russell P.; Manohar, Swarnima; Masters, Daniel; Morales-Calderon, Maria; Prato, Lisa A.; Rodigas, Timothy J.; Salvato, Mara; Schurr, Steven D.; Scoville, Nicholas Z.; Simcoe, Robert A.; Stapelfeldt, Karl R.; Stern, Daniel; Stock, Nathan D.; Vacca, William D. (2011). "The First Hundred Brown Dwarfs Discovered by the Wide-field Infrared Survey Explorer (WISE)". The Astrophysical Journal Supplement. 197 (2): 19. arXiv:1108.4677v1Freely accessible. Bibcode:2011ApJS..197...19K. doi:10.1088/0067-0049/197/2/19. 
  7. ^ Lucas, Philip W.; Tinney; Burningham; Leggett; Pinfield; Smart; et al. (2010). "Discovery of a very cool brown dwarf amongst the ten nearest stars to the Solar System". arXiv:1004.0317v1Freely accessible [astro-ph.SR]. 
  8. ^ Bouy, H.; Girard, J. H. V.; Martín, E. L.; Huélamo, N.; Lucas, P. W. (2011). "Adaptive optics observations of the T10 ultracool dwarf UGPS J072227.51-054031.2". Astronomy and Astrophysics. 526: A55. arXiv:1008.3046Freely accessible. Bibcode:2011A&A...526A..55B. doi:10.1051/0004-6361/201015289. 

External links[edit]

Coordinates: Sky map 07h 22m 27.29s, −05° 40′ 30.0″