WISEPA J022623.98-021142.8

WISE 0226−0211

Keck image of WISE 0226−0211AB Credit: Keck Observatory; Brooks et al.[1]
Observation data Epoch J2000      Equinox J2000
Constellation	Cetus
Right ascension	02^h 26^m 24.20^s
Declination	−02° 11′ 37.66″
Characteristics
Evolutionary stage	brown dwarf
Spectral type	T8+Y0[2]
Astrometry
Proper motion (μ)	RA: -294.4 ±1.4 mas/yr[3] Dec.: -432.3 ±1.2 mas/yr[3]
Parallax (π)	56.3 ± 2.5 mas[3]
Distance	58 ± 3 ly (17.8 ± 0.8 pc)
Details[3]
WISE 0226−0211A
Temperature	686 ± 79 K
WISE 0226−0211B
Temperature	511 ± 79 K
Position (relative to WISE 0226−0211A)[2]
Component	WISE 0226−0211B
Angular distance	2.1″
Other designations
CNS5 617, WISEA J022623.99-021142.7, WISEP J022623.98-021142.8, WISE J022623.98-021142.8, EQ J0226-0211
Database references
SIMBAD	data

WISE 0226−0211 (also known as WISEPA J022623.98−021142.8) is a brown dwarf binary with a combined spectral type of T7.^[4] Its individual components have a spectral type that is as of now somewhat uncertain at T8-T8.5 for the primary and T9.5-Y0 for the secondary.^[2]

The object was first discovered in 2011 with the Wide-field Infrared Survey Explorer and follow-up observations with Keck revealed a spectral type of T7.^[4] In 2019 the same team showed that the object is a common proper motion binary with a separation of 2.1 arcseconds from Spitzer images and one H-band Keck image (acquired by David Ciardi). The H-ch2 colors suggest a spectral type of about T8-T8.5 for the primary and about Y0 for the secondary. The absolute magnitudes on the other hand suggest spectral types of about T8-T8.5 for the primary and about T9.5-Y0 for the secondary. It is suspected that the combined spectral type of T7 is in error.^[2]

See also

• List of Y-dwarfs

other late T to Y dwarf binaries:

• WISE 1217+1626 T9+Y0
• WISE J0336−0143 Y+Y
• CFBDSIR J1458+1013 T9+Y0
• WISE 0146+4234 T9+Y0
• WISE J1711+3500 T8+T9.5

References

1. Brooks, Hunter; Kirkpatrick, J. Davy; Meisner, Aaron M.; Gelino, Christopher R.; Bardalez Gagliuffi, Daniella C.; Marocco, Federico; Schneider, Adam C.; Faherty, Jacqueline K.; Casewell, S. L.; Raghu, Yadukrishna; Kuchner, Marc J.; Backyard Worlds: Planet 9 Collaboration (2023-06-01). "Long-term 4.6 μm Variability in Brown Dwarfs and a New Technique for Identifying Brown Dwarf Binary Candidates". The Astronomical Journal. 165 (6): 232. arXiv:2304.05630. Bibcode:2023AJ....165..232B. doi:10.3847/1538-3881/acccf7. ISSN 0004-6256.
2. Kirkpatrick, J. Davy; Martin, Emily C.; Smart, Richard L.; Cayago, Alfred J.; Beichman, Charles A.; Marocco, Federico; Gelino, Christopher R.; Faherty, Jacqueline K.; Cushing, Michael C.; Schneider, Adam C.; Mace, Gregory N.; Tinney, Christopher G.; Wright, Edward L.; Lowrance, Patrick J.; Ingalls, James G. (2019-02-01). "Preliminary Trigonometric Parallaxes of 184 Late-T and Y Dwarfs and an Analysis of the Field Substellar Mass Function into the "Planetary" Mass Regime". The Astrophysical Journal Supplement Series. 240 (2): 19. arXiv:1812.01208. Bibcode:2019ApJS..240...19K. doi:10.3847/1538-4365/aaf6af. ISSN 0067-0049.
3. 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: 7. arXiv:2011.11616. Bibcode:2021ApJS..253....7K. doi:10.3847/1538-4365/abd107. ISSN 0067-0049.
4. Kirkpatrick, J. Davy; Cushing, Michael C.; Gelino, Christopher R.; Griffith, Roger L.; Skrutskie, Michael F.; Marsh, Kenneth A.; Wright, Edward L.; Mainzer, A.; Eisenhardt, Peter R.; McLean, Ian S.; Thompson, Maggie A.; Bauer, James M.; Benford, Dominic J.; Bridge, Carrie R.; Lake, Sean E. (2011-12-01). "The First Hundred Brown Dwarfs Discovered by the Wide-field Infrared Survey Explorer (WISE)". The Astrophysical Journal Supplement Series. 197 (2): 19. arXiv:1108.4677. Bibcode:2011ApJS..197...19K. doi:10.1088/0067-0049/197/2/19. ISSN 0067-0049.