CWISEP J1446−2317 (CWISEP J144606.62−231717.8, CWISEP 1446−2317) is a brown dwarf or planetary-mass object.[4] It is a Y-dwarf with a spectral type of Y1.[1]

CWISEP J1446−2317

JWST NIRCam image of CWISEP J1446−2317 (faint orange "star" at the center)
Observation data
Epoch J2000      Equinox J2000
Constellation Libra
Right ascension 14h 46m 07.43s
Declination −23° 17′ 04.33″
Characteristics
Evolutionary stage (sub-)brown dwarf
Spectral type Y1[1]
Astrometry
Proper motion (μ) RA: -796.1 ±48.8 mas/yr[2]
Dec.: -913.0 ±24.3 mas/yr[2]
Parallax (π)103.8 ± 5.0 mas[1]
Distance31 ± 2 ly
(9.6 ± 0.5 pc)
Details
Mass4–14[3] MJup
Luminosity (bolometric)10-6.779 ± 0.043[1] L
Temperature366 ±14[1] K
Age1.5–6.5[3] Gyr
Other designations
CWISE J144606.58-231719.0, CWISEP J144606.62-231717.8
Database references
SIMBADdata

CWISEP J1446−2317 was discovered as an unusual red object (Spitzer ch1-ch2 = 3.71 ±0.44 mag) in the new combined WISE/NEOWISE catalog, called CatWISE. The object was found using supervised machine-learning, by using XGBoost. The temperature was estimated to be lower than 381 Kelvin for this object.[4] Follow-up observations however revised the color to ch1-ch2 = 2.986 ±0.048 mag, making it the fifth reddest object at the time, with an estimated temperature of 310−360 K. The mass was estimated between 2 and 20 MJ for an age range of ~500 Myr–13 Gyr. The object is however unlikely to be young because of its high tangential velocity of around 60 km/s. If this object is similar to other ultracool dwarf in the solar neighbourhood, it would have an age of about 1.5–6.5 Gyrs and therefore a mass of 4–14 MJ according to the authors.[3]

In 2024 observations of CWISEP J1446−2317 with JWST were published. These observations were carried out with NIRSpec and MIRI spectroscopy. These observations established this object to have a spectral type of Y1, due to the narrow J-band peaks. There were however difficulties to precisely determine the spectral type. CWISEP J1446−2317 is not discussed in detail in this work. The authors however mention that they detect absorption features in their sample. These include water vapor, methane, ammonia, carbon monoxide and carbon dioxide. None of the objects in their sample show absorption due to phosphine, which is predicted to be present in the atmosphere of these cold objects.[1]

See also

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References

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  1. ^ a b c d e f Beiler, Samuel A.; Cushing, Michael C.; Kirkpatrick, J. Davy; Schneider, Adam C.; Mukherjee, Sagnick; Marley, Mark S.; Marocco, Federico; Smart, Richard L. (11 Jul 2024). "Precise Bolometric Luminosities and Effective Temperatures of 23 late-T and Y dwarfs Obtained with JWST". arXiv:2407.08518 [astro-ph.SR].
  2. ^ Kirkpatrick, J. Davy; Gelino, Christopher R.; Faherty, Jacqueline K.; Meisner, Aaron M.; Caselden, Dan; Schneider, Adam C.; Marocco, Federico; Cayago, Alfred J.; Smart, R. L.; Eisenhardt, Peter R.; Kuchner, Marc J.; Wright, Edward L.; Cushing, Michael C.; Allers, Katelyn N.; Bardalez Gagliuffi, Daniella C. (2021-03-01). "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. 253 (1): 7. arXiv:2011.11616. Bibcode:2021ApJS..253....7K. doi:10.3847/1538-4365/abd107. ISSN 0067-0049.
  3. ^ a b c Marocco, Federico; Kirkpatrick, J. Davy; Meisner, Aaron M.; Caselden, Dan; Eisenhardt, Peter R. M.; Cushing, Michael C.; Faherty, Jacqueline K.; Gelino, Christopher R.; Wright, Edward L. (2020-01-01). "Improved Infrared Photometry and a Preliminary Parallax Measurement for the Extremely Cold Brown Dwarf CWISEP J144606.62-231717.8". The Astrophysical Journal. 888 (2): L19. arXiv:1912.07692. Bibcode:2020ApJ...888L..19M. doi:10.3847/2041-8213/ab6201. ISSN 0004-637X.
  4. ^ a b Meisner, Aaron M.; Caselden, Dan; Kirkpatrick, J. Davy; Marocco, Federico; Gelino, Christopher R.; Cushing, Michael C.; Eisenhardt, Peter R. M.; Wright, Edward L.; Faherty, Jacqueline K.; Koontz, Renata; Marchese, Elijah J.; Khalil, Mohammed; Fowler, John W.; Schlafly, Edward F. (2020-02-01). "Expanding the Y Dwarf Census with Spitzer Follow-up of the Coldest CatWISE Solar Neighborhood Discoveries". The Astrophysical Journal. 889 (2): 74. arXiv:1911.12372. Bibcode:2020ApJ...889...74M. doi:10.3847/1538-4357/ab6215. ISSN 0004-637X.