WISE 0647−6232
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:
- using the Infrared Array Camera (IRAC) on Spitzer Space Telescope, starting from MJD 55458.43 (possibly 16 September 2010);
- J- and H-band images using Persson's Auxiliary Nasmyth Infrared Camera (PANIC) at the 6.5-meter Magellan Baade telescope at the Las Campanas Observatory, Chile, on 25 November 2010;
- with the FourStar infrared camera also at Magellan Baade telescope on 15 January 2013 and 23 March 2013;
- with the Folded-port InfraRed Echellette (FIRE) spectrograph also at Magellan Baade telescope on 24 March 2013;
- using the Wide Field Camera 3 (WFC3) on Hubble Space Telescope on 13–14 May 2013, and pre-image was obtained on 11 February 2013.
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
−0.2 pc, or 32.5+0.8
−0.8 ly.
| Source | Parallax, mas | Distance, pc | Distance, ly | Ref. |
|---|---|---|---|---|
| Kirkpatrick et al. (2013) | 115 ± 12 | 8.7 −0.8 |
28.4 −2.7 |
|
| Kirkpatrick et al. (2019) | 100.3 ± 2.4 | 10.0 −0.2 |
32.5 −0.8 |
The best 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). For ages from 0.1 to more than 10 Gyr log(g)=4.0–5.0.
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
- ^ 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.
- ^ 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.
- ^ 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.
