WISE J2354+0240
WISE J2354+0240 is a brown dwarf in the constellation of Pisces. From Wikipedia, the free encyclopedia
WISE J2354+0240 (WISE J235402.77+024015.0, WISE 2354+0240) is a brown dwarf or free-floating planetary-mass object. It is a Y-dwarf, meaning it is one of the coldest directly imaged astronomical objects.[1]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Pisces |
| Right ascension | 23h 54m 02.42s |
| Declination | +02° 40′ 18.54″ |
| Characteristics | |
| Evolutionary stage | brown dwarf or planetary-mass object |
| Spectral type | Y1[1] |
| Astrometry | |
| Proper motion (μ) | RA: 503.5 ±2.3 mas/yr[1] Dec.: -399.5 ±2.2 mas/yr[1] |
| Parallax (π) | 130.6±3.3 mas[1] |
| Distance | 25.0 ± 0.6 ly (7.7 ± 0.2 pc) |
| Details | |
| Mass | 11 ±3[2] MJup |
| Radius | 0.101[3][a] R☉ |
| Luminosity (bolometric) | 10−6.800 ±0.023[3] L☉ |
| Surface gravity (log g) | 4.0−5.0[1] cgs |
| Temperature | 362+10 −12[3] K |
| Age | >1.5[1] Gyr |
| Other designations | |
| WISEA J235402.79+024014.1, CNS5 5897, WISE J235402.77+024015.0 | |
| Database references | |
| SIMBAD | data |
It was discovered in 2015, using the Wide-field Infrared Survey Explorer and spectroscopy from the Hubble Space Telescope. The authors find that the J-band peak in the spectrum is narrower than the Y0 standard and therefore assigned a spectral type of Y1, with an estimated temperature of 300−400 Kelvin. The age was estimated to be at least 1.5 billion years.[1] Parallax measurement places this object at 7.7 parsec from the Solar System.[4]
Near-infrared photometry was later obtained with Hubble and a temperature of 335 ±11 K and a mass of 11 ±3 MJ was estimated.[2] WISE 2354+0240 was observed with the James Webb Space Telescope and the temperature was estimated to be 362+10
−12 K. The object is not described in detail in this work. The authors however mention that they see a number of absorption features in their sample, including water vapor, methane, ammonia, carbon monoxide and carbon dioxide. They note that none of their objects show absorption due to phosphine, which is predicted to occur in these objects.[3]
See also
- WISE J0825+2805 another Y-dwarf discovered by Schneider et al. 2015
Notes
References
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