WISEPA J161705.75+180714.3

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Coordinates: Sky map 16h 17m 05.74s, +18° 07′ 14.21″

WISEPA J161705.75+180714.3
Observation data
Epoch MJD 55424.22[1]      Equinox J2000[1]
Constellation Hercules
Right ascension 16h 17m 05.74s[1]
Declination 18° 07′ 14.21″[1]
Spectral type T8[2][1][3]
Apparent magnitude (Y) 18.71 ± 0.04[2]
Apparent magnitude (J (MKO filter system)) 17.659 ± 0.080[1]
Apparent magnitude (H (MKO filter system)) 18.234 ± 0.078[1]
Proper motion (μ) RA: -46 ± 231[1] mas/yr
Dec.: -89 ± 174[1] mas/yr
Distance ~ 50.2[3] ly
(~ 15.4 ± 0.6[3] pc)
Mass 7 ± 3[2] MJup
Surface gravity (log g) 4.0 ± 0.3[2] cgs
Temperature 600 ± 30[2] K
Age 0.2 ± 0.3[2] Gyr
Other designations
WISEPA J161705.75+180714.3[1]
WISE J1617+1807[1]

WISEPA J161705.75+180714.3 (designation abbreviated to WISE 1617+1807, or WISE J1617+1807) is a brown dwarf of spectral class T8,[2][1][3] located in constellation Hercules at approximately 50 light-years from Earth.[3]


WISE 1617+1807 was discovered in 2011 by Burgasser et al. from data, collected by Wide-field Infrared Survey Explorer (WISE) Earth-orbiting satellite — NASA infrared-wavelength 40 cm (16 in) space telescope, which mission lasted from December 2009 to February 2011.

In 2010 Burgasser et al. had conducted follow-up observations of WISE 1617+1807:

In 2011 Burgasser et al. published a paper in The Astrophysical Journal, where they presented discovery of five new found by WISE brown dwarfs, including WISE 1617+1807.[2] Also, this is one of six earliest brown dwarf discoveries from data, collected by WISE, — published before Kirkpatrick et al. (2011)[1]


Trigonometric parallax of WISE 1617+1807 is not yet measured. Therefore, there are only distance estimates of this object, obtained by indirect — spectrofotometric — means (see table).

WISE 1617+1807 distance estimates

Source Parallax, mas Distance, pc Distance, ly Ref.
Burgasser et al. (2011)
13.0 ± 1.5 42.4 ± 4.9 [2]
Burgasser et al. (2011)
(spectral model fit)
13.1 ± 0.6 42.7 ± 2.0 [2]
Kirkpatrick et al. (2011) ~12.7 ~41.4 [1]
Kirkpatrick et al. (2012) ~15.4 ~50.2 [3]

Non-trigonometric distance estimates are marked in italic.

Failed attempt to detect binarity[edit]

In 2011 Gelino et al. examined for binarity nine brown dwarfs using Laser Guide Star Adaptive Optics system (LGS-AO) on Keck II telescope on Mauna Kea; seven of these nine brown dwarfs were also newfound, and two were discovered before, including WISE 1617+1807. These observations had indicated that two of these nine brown dwarfs are binary, but the other seven, including WISE 1617+1807, are single brown dwarfs.

Clouds and young age[edit]

According its discovery paper, WISE 1617+1807 is a cloudy and young brown dwarf of age about 0.2 (0 to 0.5) Gyr.[2]

Properties of WISE 1617+1807 as well as other similar objects may indicate a trend that younger brown dwarf have cloudier atmospheres.[2]

See also[edit]

The other five earliest brown dwarf discoveries from data collected by WISE:

The other eight objects, checked for binarity by Gelino et al. (2011) on Keck II:[5]


  1. ^ Presented in Gelino et al. (2011), but this is not mentioned in Kirkpatrick et al. (2011) and Kirkpatrick et al. (2012) — according these two articles, the only discovery paper of WISE 0750+2725 is Kirkpatrick et al. (2011).


  1. ^ a b c d e f g h i j k l m n 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
  2. ^ a b c d e f g h i j k l m Burgasser, Adam J.; Cushing, Michael C.; Kirkpatrick, J. Davy; Gelino, Christopher R.; Griffith, Roger L.; Looper, Dagny L.; Tinney, Christopher; Simcoe, Robert A.; Bochanski, John J.; Skrutskie, Michael F.; Mainzer, A.; Thompson, Maggie A.; Marsh, Kenneth A.; Bauer, James M.; Wright, Edward L. (2011). "Fire Spectroscopy of Five Late-type T Dwarfs Discovered with the Wide-field Infrared Survey Explorer". The Astrophysical Journal 735 (2): 116. arXiv:1104.2537. Bibcode:2011ApJ...735..116B. doi:10.1088/0004-637X/735/2/116.  edit
  3. ^ a b c d e f 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. (2012). "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.  edit
  4. ^ a b Mainzer, A.; Cushing, Michael C.; Skrutskie, M.; Gelino, C. R.; Kirkpatrick, J. Davy; Jarrett, T.; Masci, F.; Marley, Mark S.; Saumon, D.; Wright, E.; Beaton, R.; Dietrich, M.; Eisenhardt, P.; Garnavich, P.; Kuhn, O.; Leisawitz, D.; Marsh, K.; McLean, I.; Padgett, D.; Rueff, K. (2011). "The First Ultra-cool Brown Dwarf Discovered by the Wide-field Infrared Survey Explorer". The Astrophysical Journal 726 (1): 30. arXiv:1011.2279. Bibcode:2011ApJ...726...30M. doi:10.1088/0004-637X/726/1/30.  edit
  5. ^ Gelino, Christopher R.; Kirkpatrick, J. Davy; Cushing, Michael C.; Eisenhardt, Peter R.; Griffith, Roger L.; Mainzer, Amanda K.; Marsh, Kenneth A.; Skrutskie, Michael F.; Wright, Edward L. (2011). "WISE Brown Dwarf Binaries: The Discovery of a T5+T5 and a T8.5+T9 System". The Astronomical Journal 142 (2): 57. arXiv:1106.3142. Bibcode:2011AJ....142...57G. doi:10.1088/0004-6256/142/2/57.  edit