WISE 0647-6232

From Wikipedia, the free encyclopedia
Jump to: navigation, search

Coordinates: Sky map 06h 47m 23.2270s, −62° 32′ 39.744″

WISE J064723.23-623235.5
Observation data
Epoch J2000[1]      Equinox J2000[1]
Constellation Pictor
Right ascension 06h 47m 23.2270s[1]
Declination −62° 32′ 39.744″[1]
Spectral type Y1 ± 0.5[1]
Apparent magnitude (J (LCO filter system)) >23.0 ± 0.1[1]
Apparent magnitude (J (MKO filter system)) 22.65 ± 0.27[1]
Apparent magnitude (H (LCO filter system)) >21.7 ± 0.3[1]
Apparent magnitude (H (MKO filter system)) 23.40 ± 0.29[1]
Apparent magnitude (W1) >19.09[1]
Apparent magnitude (W2) 15.32 ± 0.08[1]
Apparent magnitude (W3) >13.49[1]
Apparent magnitude (W4) >9.66[1]
Proper motion (μ) RA: 7 ± 12[1] mas/yr
Dec.: 387 ± 22[1] mas/yr
Parallax (π) 115 ± 12[1] mas
Distance approx. 28 ly
(approx. 8.7 pc)
Mass ∼5—30[1] MJup
Surface gravity (log g) 3.0—5.0[1] cgs
Temperature 350—400[1] K
Other designations
WISE J064723.23-623235.5[1]
WISE 0647-6232[1]

WISE 0647-6232 (full designation is WISE J064723.23-623235.5) is a nearby brown dwarf of spectral type Y1 ± 0.5, located in constellation Pictor at approximately 28 light-years from Earth. It is one of the two or three reddest and one of the four latest-type brown dwarfs known.[1]

History of observations[edit]


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 09 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).[1]


Preliminary parallax of WISE 0647-6232, measured using WISE, HST and Spitzer and published in its discovery paper is 115 ± 12 mas, corresponding to a distance 8.7+1.0
pc, or 28.4+3.3

WISE 0647-6232 distance estimates

Source Parallax, mas Distance, pc Distance, ly Ref.
Kirkpatrick et al. (2013) 115 ± 12 8.7+1.0

The best estimate is marked in bold.


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.[1]

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

The other three latest-type Y dwarfs are: WISE 0350-5658 (Y1), WISE 0535-7500 (≥Y1)[2] and WISE 1828+2650 (≥Y2).[1]


  1. ^ a b c d e f g h i j k l m n o p q r s t u v w x y z aa 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". arXiv:1308.5372v1 [astro-ph.SR]. Bibcode 2013arXiv1308.5372K.
  2. ^ 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.  edit