WISE 0647−6232

WISE 0647−6232

WISE 0647-6232
Credit: unWISE
Observation data
Epoch J2000      Equinox J2000
Constellation Pictor
Right ascension 06h 47m 23.2270s
Declination −62° 32′ 39.744″
Characteristics
Spectral type Y1±0.5
Apparent magnitude (J (LCO filter system)) >23.0±0.1
Apparent magnitude (J (MKO filter system)) 22.65±0.27
Apparent magnitude (H (LCO filter system)) >21.7±0.3
Apparent magnitude (H (MKO filter system)) 23.40±0.29
Apparent magnitude (W1) >19.09
Apparent magnitude (W2) 15.32±0.08
Apparent magnitude (W3) >13.49
Apparent magnitude (W4) >9.66
Astrometry
Proper motion (μ) RA: +1.19±1.18 mas/yr
Dec.: +393.81±0.78 mas/yr
Parallax (π)110.06±2.25 mas
Distance29.6 ± 0.6 ly
(9.1 ± 0.2 pc)
Details
Mass5–30 MJup
Surface gravity (log g)3.0–5.0 cgs
Temperature350–400 K
Other designations
WISE J064723.23−623235.5
WISE 0647−6232
Database references
SIMBADdata

WISE J064723.23−623235.5 (abbreviated WISE 0647−6232) is a nearby brown dwarf of spectral type Y1±0.5, located in constellation Pictor at approximately 32.5 light-years from Earth. It is one of the two or three reddest and one of the four latest-type brown dwarfs known.

History of observations

Discovery

WISE 0647−6232 was discovered by Kirkpatrick et al. from data, collected by 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. The discovery was announced in 2013. WISE 0647−6232 was first imaged by WISE on 9 May 2010. On 17 June 2010 after preliminary data processing it was uncovered as a very cold brown dwarf candidate.

Then were carried out follow-up observations:

On 25 August 2013 Kirkpatrick et al. submitted the discovery paper to The Astrophysical Journal. WISE 0647−6232 became the 17th Y-type dwarf discovered and confirmed spectroscopically (in addition, WD 0806-661B is also almost certainly a Y-type dwarf, which was found before discovery of WISE 0647−6232, but it still lacks a spectroscopical confirmation).

Distance

Currently the most accurate distance estimate of WISE 0647−6232 is a trigonometric parallax, published in 2019 by Kirkpatrick et al.: 10.0±0.2 pc, or 32.5±0.8 ly.

WISE 0647-6232 distance estimates
SourceParallax, masDistance, pcDistance, lyRef.
Kirkpatrick et al. (2013)115±128.7+1.0
−0.8		28.4+3.3
−2.7
Kirkpatrick et al. (2019)100.3±2.410.0±0.232.5±0.8

The most reliable estimate is marked in bold.

Properties

WISE 0647−6232 has effective temperature 350–400 K and mass ~5–30 MJup, but its kinematics suggests that it may belong to Columba moving group (probability of this is 92.9%, and corresponding radial velocity should be ~22 km/s), if it is so, it may be very young (~30 Myr) and have even lower mass (<2 MJup). Its blue J − H color may suggest that its surface gravity may be relatively low (log(g)=3.0–3.5, where g is in units of cm·s−2). For ages from 0.1 to more than 10 Gyr log(g)=4.0–5.0. One team found a 93.2% probability of this object belonging to a group called OCEMG, which would result in a mass of 4.6+3.0
−2.2 MJ.

The only redder than WISE 0647−6232 confirmed Y dwarf is WISE 1828+2650. WD 0806-661B may also be redder than WISE 0647−6232.

The other three latest-type Y dwarfs are: WISE 0350−5658 (Y1), WISE 0535−7500 (≥Y1) and WISE 1828+2650 (≥Y2).

See also

References

  1. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 Kirkpatrick, J. Davy; Cushing, Michael C.; Gelino, Christopher R.; Beichman, Charles A.; Tinney, C. G.; Faherty, Jacqueline K.; Schneider, Adam; Mace, Gregory N. (2013). "Discovery of the Y1 Dwarf WISE J064723.23-623235.5". The Astrophysical Journal. 776 (2): 128. arXiv:1308.5372v1. Bibcode:2013ApJ...776..128K. doi:10.1088/0004-637X/776/2/128. S2CID 6230841.
  2. 1 2 3 Fontanive, Clémence; Bedin, Luigi R.; Albert, Loïc; Gagliuffi, Daniella C. Bardalez (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. 537 (1): 419. arXiv:2412.16679. Bibcode:2025MNRAS.537..419F. doi:10.1093/mnras/staf032.
  3. 1 2 3 Kirkpatrick, J. Davy; Martin, Emily C.; Smart, Richard L.; Cayago, Alfred J.; Beichman, Charles A.; Marocco, Federico; et al. (February 2019). "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): 69. arXiv:1812.01208. Bibcode:2019ApJS..240...19K. doi:10.3847/1538-4365/aaf6af. 19.
  4. ↑ Gagné, Jonathan; Moranta, Leslie; Faherty, Jacqueline K.; Curtis, Jason Lee; Bickle, Thomas P.; Couture, Dominic; Chiasson David, Amélie; Christie, Katie; Lambier, Samantha; Leclerc, Elise; Poliquin, Livia; Belzile, Danika; Mamajek, Eric E. (17 Feb 2026). "The Montreal Open Clusters and Associations (MOCA) Database: A Census of Nearby Associations, Open Clusters, and Young Substellar Objects within 500 pc of the Sun". arXiv:2602.15695 [astro-ph.SR].
  5. ↑ Marsh, Kenneth A.; Wright, Edward L.; Kirkpatrick, J. Davy; Gelino, Christopher R.; Cushing, Michael C.; Griffith, Roger L.; Skrutskie, Michael F.; Eisenhardt, Peter R. (2013). "Parallaxes and Proper Motions of Ultracool Brown Dwarfs of Spectral Types Y and Late T". The Astrophysical Journal. 762 (2): 119. arXiv:1211.6977. Bibcode:2013ApJ...762..119M. doi:10.1088/0004-637X/762/2/119. S2CID 42923100.