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]
Characteristics
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]
Astrometry
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)
Details
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
SIMBAD data

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]

Discovery[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
−0.5
parsecs.[1]

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]

Distance[edit]

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]

UGPS J072227.51-054031.2 distance estimates

Source Parallax, mas Distance, pc Distance, ly Ref.
Lucas et al. (2010)
(e-print version 1)
340 ± 40 2.94+0.39
−0.31
9.6+1.3
−1
[7]
Lucas et al. (2010)
(UKIRT only)
237 ± 41 4.2+0.9
−0.6
13.8+2.9
−2
[1][4]
Lucas et al. (2010)
(UKIRT + 2MASS)
246 ± 33 4.1+0.6
−0.5
13.3+2.1
−1.6
[1]
Cushing et al. (2011) 11.1 (10.4–11.1) 36.2 (33.9–36.2) [1]
Leggett et al. (2012) 242.8 ± 2.4 4.12 ± 0.04 13.43 ± 0.13 [3]
Dupuy & Kraus (2013) 211 ± 23[~ 1] 4.7+0.6
−0.5
15.5+1.9
−1.5
[5]

Non-trigonometric distance estimates are marked in italic. The best estimate is marked in bold.

Space motion[edit]

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

UGPS J072227.51-054031.2 proper motion estimates

Source μ,
mas/yr
P. A.,
°
μRA,
mas/yr
μDEC,
mas/yr
Ref.
Lucas et al. (2010)
(e-print version 1)
929 ± 8 291.8 ± 0.2 −863 345 [7]
Lucas et al. (2010)
(UKIRT only)
972 ± 8 291.2 ± 0.2 −906 351 [1]
Lucas et al. (2010)
(UKIRT + 2MASS)
967 ± 8 291.1 ± 0.2 −902 348 [1]
Leggett et al. (2012) 970 291 −904.14 ± 1.71 352.025 ± 1.21 [3]
Dupuy & Kraus (2013) 959 ± 15 291.3 ± 0.7 −893 ± 16 349 ± 10 [5]

The most accurate estimates are marked in bold.

Radial velocity of UGPS 0722-05, measured by Bochanski et al. and published in 2011, is 46.9 ± 2.5 km/s.[4][~ 2]

Properties[edit]

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]

Notes[edit]

  1. ^ Relative parallax.
  2. ^ 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).

References[edit]

  1. ^ a b c d e f g h i j k l m n o p q r 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:1004.0317. Bibcode:2010MNRAS.408L..56L. doi:10.1111/j.1745-3933.2010.00927.x.  edit
  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)". arXiv:1108.4678v1 [astro-ph.SR]. Bibcode 2011ApJ...743...50C. doi:10.1088/0004-637X/743/1/50. edit
  3. ^ a b c d e f g h i 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:1201.2973. Bibcode:2012ApJ...748...74L. doi:10.1088/0004-637X/748/2/74.  edit
  4. ^ a b c d e f 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:1109.2897. Bibcode:2011AJ....142..169B. doi:10.1088/0004-6256/142/5/169.  edit
  5. ^ a b c d e f g Dupuy, Trent J.; Kraus, Adam L. (2013). "Distances, Luminosities, and Temperatures of the Coldest Known Substellar Objects". arXiv:1309.1422v1 [astro-ph.SR]. Bibcode 2013arXiv1309.1422D.
  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:1108.4677v1. Bibcode:2011ApJS..197...19K. doi:10.1088/0067-0049/197/2/19.  edit
  7. ^ a b c 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:1004.0317v1 [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:1008.3046. Bibcode:2011A&A...526A..55B. doi:10.1051/0004-6361/201015289.  edit

External links[edit]

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