Epoch MJD 55424.22 Equinox J2000
|Right ascension||16h 17m 05.74s|
|Declination||18° 07′ 14.21″|
|Apparent magnitude (Y)||18.71 ± 0.04|
|Apparent magnitude (J (MKO filter system))||17.659 ± 0.080|
|Apparent magnitude (H (MKO filter system))||18.234 ± 0.078|
|Proper motion (μ)||RA: -46 ± 231 mas/yr
Dec.: -89 ± 174 mas/yr
|Distance||~ 50.2 ly
(~ 15.4 ± 0.6 pc)
|Mass||7 ± 3 MJup|
|Surface gravity (log g)||4.0 ± 0.3 cgs|
|Temperature||600 ± 30 K|
|Age||0.2 ± 0.3 Gyr|
WISEPA J161705.75+180714.3 (designation abbreviated to WISE 1617+1807, or WISE J1617+1807) is a brown dwarf of spectral class T8, located in constellation Hercules at approximately 50 light-years from Earth.
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:
- on 2010 March 21 (UT) JH-band photometry with the SpartanIRC on the 4.1 m SOAR telescope;
- on 2010 April 1 (UT) Y-band photometry with the FanCam, a near-infrared imager mounted on the University of Virginia’s 0.8 m Fan Mountain telescope;
- on 2010 April 7 (UT) spectroscopy with the FIRE spectrograph mounted on the Magellan 6.5 m Baade Telescope located at Las Campanas Observatory in Chile.
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. Also, this is one of six earliest brown dwarf discoveries from data, collected by WISE, — published before Kirkpatrick et al. (2011)
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|||
|Burgasser et al. (2011)
(spectral model fit)
|13.1 ± 0.6||42.7 ± 2.0|||
|Kirkpatrick et al. (2011)||~12.7||~41.4|||
|Kirkpatrick et al. (2012)||~15.4||~50.2|||
Non-trigonometric distance estimates are marked in italic.
Failed attempt to detect binarity
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
Properties of WISE 1617+1807 as well as other similar objects may indicate a trend that younger brown dwarf have cloudier atmospheres.
The other five earliest brown dwarf discoveries from data collected by WISE:
- published by Mainzer et al. (2011):
- WISE 0458+6434 (T8.5 + T9.5 binary)
- published by Burgasser et al. (2011):
The other eight objects, checked for binarity by Gelino et al. (2011) on Keck II:
- binarity found:
- binarity not found:
- 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).
- 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.
- 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.
- 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.
- 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.
- 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.