WISEPA J173835.53+273258.9 explained
WISEPA J173835.53+273258.9 (abbreviated WISE 1738+2732) is a brown dwarf of spectral class Y0, located in the constellation Hercules at 24.9 light-years from Earth.
History of observations
Discovery
WISE 1738+2732 was discovered in 2011 from data, collected by the 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. WISE 1738+2732 has two discovery papers: Kirkpatrick et al. (2011) and Cushing et al. (2011), however, basically with the same authors and published nearly simultaneously.
- Kirkpatrick et al. presented discovery of 98 new found by WISE brown dwarf systems with components of spectral types M, L, T and Y, among which also was WISE 1738+2732.[1]
- Cushing et al. presented discovery of seven brown dwarfs — one of T9.5 type, and six of Y-type — first members of the Y spectral class, ever discovered and spectroscopically confirmed, including "archetypal member" of the Y spectral class WISE 1828+2650, and WISE 1738+2732. These seven objects are also the faintest seven of 98 brown dwarfs, presented in Kirkpatrick et al. (2011).
Distance
Currently the most accurate distance estimate of WISE 1738+2732 is a trigonometric parallax, published in 2021 by Kirkpatrick et al.:, corresponding to a distance of, or .
Space motion
WISE 1738+2732 has a proper motion of milliarcseconds per year.
Properties
The object's temperature estimate is 350 (350–400) K. Its spectrum is similar with spectrum of another Y-dwarf WISE 1405+5534.
Disequilibrium chemistry models suggest that this Y-dwarf has a low mass of about 3-9, making it a possible isolated planetary-mass object, together with WISE 0350-5658.[2] A more recent paper finds a mass of 5-14 .[3]
WISE 1405 is variable in the near- and mid-infrared. The observations were made with the Gemini Observatory and Spitzer. It has a rotation period of 6.0±0.1 hours and the amplitude is 3% for 4.5 μm and may be as high as 5-30% in the near-infrared. This dependence on wavelength can be reproduced with patchy cloud layers made up of potassium chloride (KCl) and sodium sulfide (Na2S).[4]
See also
References
- Marsh . Kenneth A. . Wright, Edward L. . Kirkpatrick, J. Davy . Gelino, Christopher R. . Cushing, Michael C. . Griffith, Roger L. . Skrutskie, Michael F. . Eisenhardt, Peter R. . 2013 . Parallaxes and Proper Motions of Ultracool Brown Dwarfs of Spectral Types Y and Late T . . 762 . 2 . 119 . 1211.6977 . 2013ApJ...762..119M . 10.1088/0004-637X/762/2/119. 42923100 .
Notes and References
- These 98 brown dwarf systems are only among first, not all brown dwarf systems, discovered from data, collected by WISE: six discoveries were published earlier (however, also listed in Kirkpatrick et al. (2011)) in Mainzer et al. (2011) and Burgasser et al. (2011), and the other discoveries were published later.
- Leggett . S. K. . Tremblin . P. . Saumon . D. . Marley . M. S. . Morley . Caroline V. . Amundsen . D. S. . Baraffe . I. . Chabrier . G. . 2016-06-01 . Near-infrared Spectroscopy of the Y0 WISEP J173835.52+273258.9 and the Y1 WISE J035000.32-565830.2: The Importance of Non-equilibrium Chemistry . The Astrophysical Journal . 824 . 1 . 2 . 10.3847/0004-637X/824/1/2 . 1603.09400 . 2016ApJ...824....2L . 0004-637X . free .
- Leggett . S. K. . Tremblin . P. . Esplin . T. L. . Luhman . K. L. . Morley . Caroline V. . 2017-06-01 . The Y-type Brown Dwarfs: Estimates of Mass and Age from New Astrometry, Homogenized Photometry, and Near-infrared Spectroscopy . The Astrophysical Journal . 842 . 2 . 118 . 10.3847/1538-4357/aa6fb5 . 1704.03573 . 2017ApJ...842..118L . 0004-637X . free .
- Leggett . S. K. . Cushing . Michael C. . Hardegree-Ullman . Kevin K. . Trucks . Jesica L. . Marley . M. S. . Morley . Caroline V. . Saumon . D. . Carey . S. J. . Fortney . J. J. . Gelino . C. R. . Gizis . J. E. . Kirkpatrick . J. D. . Mace . G. N. . 2016-10-01 . Observed Variability at 1 and 4 μm in the Y0 Brown Dwarf WISEP J173835.52+273258.9 . The Astrophysical Journal . 830 . 2 . 141 . 10.3847/0004-637X/830/2/141 . 1607.07888 . 2016ApJ...830..141L . 0004-637X . free .