WISE 0535-7500

WISE J053516.80−750024.9

WISE 0535-7500 Credit: NASA/ESA/CSA JWST MIRI
Observation data Epoch J2000[1]      Equinox J2000[1]
Constellation	Mensa
Right ascension	05h 35m 16.8s[1]
Declination	−75° 00′ 24.9″[1]
Characteristics
Spectral type	Y1[2]
Apparent magnitude (J (MKO-NIR filter system))	>21.1[1]
Apparent magnitude (H (MKO-NIR filter system))	>21.6[1]
Astrometry
Proper motion (μ)	RA: −127±4 mas/yr[3] Dec.: 13±4 mas/yr[3]
Parallax (π)	68.7±2.0 mas[2]
Distance	47 ± 1 ly (14.6 ± 0.4 pc)
Details[4]
Single object case
Mass	22+3 −4 MJup
Radius	1.53±0.04 RJup
Luminosity	10−6.216±0.026[2] L☉
Surface gravity (log g)	4.37+0.06 −0.07 cgs
Temperature	395±6 K
Metallicity	[ M / H ] {\displaystyle {\begin{smallmatrix}\left[{\ce {M}}/{\ce {H}}\right]\end{smallmatrix}}}  = +0.23±0.05
Age	2 Gyr
A (binary case)
Mass	18[5] MJup
Surface gravity (log g)	4.5[5] cgs
Temperature	480[6] K
Age	5[5] Gyr
B (binary case)
Mass	12[5] MJup
Surface gravity (log g)	4.5[5] cgs
Temperature	340[6] K
Age	5[5] Gyr
Other designations
WISE J053516.80−750024.9,[1] WISE 0535−7500[1]
Database references
SIMBAD	data

WISE J053516.80−750024.9 (designation abbreviated to WISE 0535−7500) is a possible binary system^[3] of two Y1-class^[2] brown dwarfs, in the constellation Mensa. Based on its parallax, its distance is roughly 48 light-years (14.6 parsecs).^[2]

History of observations

WISE 0535−7500 was discovered in 2012 by J. Davy Kirkpatrick et al. from data, collected by Wide-field Infrared Survey Explorer (WISE) Earth-orbiting satellite—NASA infrared-wavelength 40-centimetre (16 in) space telescope, which mission lasted from December 2009 to February 2011. In 2012 Kirkpatrick et al. published a paper in The Astrophysical Journal, where they presented the discovery of seven new found by WISE brown dwarfs of spectral type Y, among which also was WISE 0535−7500.^[1]

In 2014, it was found that WISE 0535 is more luminous than predicted by atmospheric models.^[7] In 2016, it was suggested that such an over-luminosity could be explained if it is, in fact, a binary system of similar components. Close imaging has not revealed any companions within the detection capacities, implying that the separation between the components is less than 1.9 astronomical units.^[8] One 2024 study found that while the overluminosity could be reasonably explained by a metal-poor atmosphere, an unresolved binary system is a better possibility. The primary was estimated to have a mass of 18 M_J and an effective temperature of 450 K (177 °C; 350 °F), while the secondary has an estimated mass of 12 M_J and an effective temperature of 350 K (77 °C; 170 °F), with a system age of 5 Gyr.^[5] Similarly, a 2026 study found that the overluminosity can be explained by either binarity or a high surface gravity with or without a metal-poor atmosphere. The components would have temperatures of 480 K (207 °C; 404 °F) and 340 K (67 °C; 152 °F) with a near-solar metallicity.^[6] For the case that WISE 0535 is single star, a mass of 22+3
−4 M_J, a radius of 1.53±0.04 R_J and an effective temperature of 395 ± 6 K (121.85 ± 6.00 °C; 251.33 ± 10.80 °F) have been measured.^[4]

WISE 0535−7500 was studied with JWST by Beiler et al. in 2024 together with 22 other late-T and Y-dwarfs. WISE 0535−7500 stands out due to it having no discernable CO₂ band and an almost undetectable CO band. This could be due a low metallicity or high surface gravity. These features make this object extremely red in Spitzer colors. This object also showed stronger NH₃ absorption when compared to objects of the same temperature. Other common prominent features like H₂O and CH₄ are present in its spectrum. But like other late-T and Y-dwarfs it is missing PH₃, which is predicted to occur for these objects.^[2]

See also

• List of star systems within 45–50 light-years
• List of Y-dwarfs

References