WISEPA J173835.53+273258.9

History of observations

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.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.
• 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).

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 . 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. A more recent paper finds a mass of 5–14 .

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).

Notes

References

References

1. (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.
2. (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.
3. (2016-10-01). "Observed Variability at 1 and 4 μm in the Y0 Brown Dwarf WISEP J173835.52+273258.9". The Astrophysical Journal.
4. (2025). "Panchromatic characterization of the Y0 brown dwarf WISEP J173835.52+273258.9 using JWST/MIRI".
5. (2011). "The Discovery of Y Dwarfs using Data from the Wide-field Infrared Survey Explorer (WISE)". The Astrophysical Journal.
6. (2011). "The First Hundred Brown Dwarfs Discovered by the Wide-field Infrared Survey Explorer (WISE)". [[The Astrophysical Journal Supplement]].
7. (2012). "Further Defining Spectral Type "Y" and Exploring the Low-mass End of the Field Brown Dwarf Mass Function". [[The Astrophysical Journal]].
8. (2014). "WISE Y Dwarfs As Probes of the Brown Dwarf-Exoplanet Connection". [[The Astrophysical Journal]].
9. (March 2021). "The Field Substellar Mass Function Based on the Full-sky 20 pc Census of 525 L, T, and Y Dwarfs". [[The Astrophysical Journal Supplement Series]].
10. (2024-12-21). "The Y Dwarf Population with HST: unlocking the secrets of our coolest neighbours -- II. Parallaxes and Proper Motions". Monthly Notices of the Royal Astronomical Society.