WISEPA J182831.08+265037.8

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Coordinates: Sky map 18h 28m 31.10s, +26° 50′ 37.79″

WISEPA J182831.08+265037.8
WISE 1828+2650.jpg
Infrared image from WISE satellite. WISE 1828+2650 is circled green dot at the centre.
Observation data
Epoch MJD 55467.61[1]      Equinox J2000[1]
Constellation Lyra
Right ascension 18h 28m 31.10s[1]
Declination 26° 50′ 37.79″[1]
Characteristics
Spectral type >Y2[2]
Apparent magnitude (J (MKO filter system)) 23.57 ± 0.35[1]
Apparent magnitude (H (MKO filter system)) 22.45 ± 0.08[2]
Astrometry
Proper motion (μ) RA: 954 ± 11[2] mas/yr
Dec.: 153 ± 12.5[2] mas/yr
Parallax (π) 70 ± 14[3] mas
Distance approx. 47 ly
(approx. 14 pc)
Details
Mass ~ 3—6 (0.5—20)[2] MJup
Temperature 250—400[2] K
Age ~ 2—4 (0.1—10)[2] Gyr
Other designations
WISEPA J182831.08+265037.8[1]
WISEP J182831.08+265037.8[2]
WISEP J1828+2650[4]
WISE J1828+2650[1]
WISE 1828+2650[1]

WISEPA J182831.08+265037.8 (designation is abbreviated to WISE 1828+2650) is a brown dwarf or free-floating planet[2] of spectral class >Y2,[2] located in constellation Lyra at approximately 47 light-years from Earth.[3] It is the "archetypal member" of the Y spectral class.[4]

History of observations[edit]

Discovery[edit]

WISE 1828+2650 was discovered in 2011 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. WISE 1828+2650 has two discovery papers: Kirkpatrick et al. (2011) and Cushing et al. (2011), however, basically with the same authors and published nearly simultaneously.[1][4]

  • Kirkpatrick et al. presented discovery of 98 new found by WISE brown dwarf systems with components of spectral types M, L, T and Y, among which also was WISE 1828+2650 — coolest of them.[1][~ 1]
  • Cushing et al. presented discovery of seven brown dwarfs — one of T9.5 type, and six of Y-type — first members of the Y spectral class, ever discovered and spectroscopically confirmed, including "archetypal member" of the Y spectral class — WISE 1828+2650.[4] These seven objects are also the faintest seven of 98 brown dwarfs, presented in Kirkpatrick et al. (2011).[1]

Distance[edit]

Currently the most accurate distance estimate of WISE 1828+2650 is a trigonometric parallax, measured using Spitzer Space Telescope and published in 2013 by Trent Dupuy and Adam Kraus: 0.070 ± 0.014 arcsec, corresponding to a distance 14.3+3.6
−2.4
pc, or 46.6+11.6
−7.8
ly.[3]

WISE 1828+2650 distance estimates

Source Parallax, mas Distance, pc Distance, ly Ref.
Kirkpatrick et al. (2011)
(Table 6)
<9.4 <30.7 [1]
Beichman et al. (2013)
(according Kirkpatrick et al. (2012))
122 ± 13 8.2+1.0
−0.8
26.7+3.2
−2.6
[5]
Beichman et al. (2013) 90 ± 9.5[~ 2] 11.2+1.3
−1.0
36.5+4.2
−3.3
[2]
Dupuy & Kraus (2013) 70 ± 14[~ 3] 14.3+3.6
−2.4
46.6+11.6
−7.8
[3]

Non-trigonometric distance estimates are marked in italic. The most precise estimate is marked in bold.

Proper motion[edit]

WISE 1828+2650 has proper motion of about 966 milliarcseconds per year.[2]

WISE 1828+2650 proper motion estimates

Source μ,
mas/yr
P. A.,
°
μRA,
mas/yr
μDEC,
mas/yr
Ref.
Kirkpatrick et al. (2011) 1084 84 1078 ± 327 118 ± 409 [1]
Beichman et al. (2013) 966 81 954 ± 11 153 ± 12.5 [2]
Dupuy & Kraus (2013) 1034 ± 15 80.4 ± 0.9 1020 ± 15 173 ± 16 [3]

Non-trigonometric distance estimates are marked in italic. The best estimate is marked in bold.

Physical properties[edit]

WISE 1828+2650 may be the coldest currently known brown dwarf or the first example of free-floating planet (it is not currently known if it is a brown dwarf or a free-floating planet).[2] It has a temperature in the range 250—400 K[2] (-23—127 °C / -10—260 °F) (initially was estimated below 300 K[4] (about 27 °C / 80 °F)). It has been assigned the latest known spectral class (>Y2,[2] initially estimated as >Y0[4]).

Mass of WISE 1828+2650 is in the range 0.5—20 MJup for ages of 0.1—10 Gyr.[2]

High tangential velocity of WISE 1828+2650, characteristic of an old disk population, indicates possible age of WISE 1828+2650 in the range 2—4 Gyr, leading to mass estimate of ~ 3—6 MJup.[2][~ 4]

WISE 1828+2650 is similar in appearance to the other Y-type object WD 0806-661 B. WD 0806-661 B could have formed as a planet close to its primary, WD 0806-661 A, and later, when the primary became a white dwarf and lost most of its mass, have migrated into a larger orbit of 2500 AU, and similarity between WD 0806-661 B and WISE 1828+2650 may indicate that WISE 1828+2650 had formed in the same way.[2]

Possible binarity[edit]

Comparison between WISE 1828+2650 and WD 0806-661 B may suggest that WISE 1828+2650 is a system of two equal-mass objects. Observations with Hubble Space Telescope (HST) and Keck-II LGS-AO system had not revealed binarity, suggesting that if any such companion exists, it would have an orbit less than 0.5 AU, and no evidence for binarity yet exists.[2]

See also[edit]

The other six discoveries of brown dwarfs, published by Cushing et al. in 2011:[4]

Notes[edit]

  1. ^ These 98 brown dwarf systems are only among first, not all brown dwarf systems, discovered from data, collected by WISE: six discoveries were published earlier (however, also listed in Kirkpatrick et al. (2011)) in Mainzer et al. (2011) and Burgasser et al. (2011), and the other discoveries were published later.
  2. ^ According Dupuy & Kraus (2013), this measurement uncertainty is likely underestimated.
  3. ^ Relative parallax.
  4. ^ This may indicate that WISE 1828+2650 is more likely a free-floating planet, not a brown dwarf, since it is below the lower mass limit for brown dwarfs (~13 MJup, see brown dwarf).

References[edit]

  1. ^ a b c d e f g h i j k l m 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.; Petty, Sara M.; Stanford, S. A.; Tsai, Chao-Wei; Bailey, Vanessa; Beichman, Charles A.; Bloom, Joshua S.; Bochanski, John J.; Burgasser, Adam J.; Capak, Peter L.; Cruz, Kelle L.; Hinz, Philip M.; Kartaltepe, Jeyhan S.; Knox, Russell P.; Manohar, Swarnima; Masters, Daniel; Morales-Calderon, Maria; Prato, Lisa A.; Rodigas, Timothy J.; Salvato, Mara; Schurr, Steven D.; Scoville, Nicholas Z.; Simcoe, Robert A.; Stapelfeldt, Karl R.; Stern, Daniel; Stock, Nathan D.; Vacca, William D. (2011). "The First Hundred Brown Dwarfs Discovered by the Wide-field Infrared Survey Explorer (WISE)". The Astrophysical Journal Supplement 197 (2): 19. arXiv:1108.4677v1. Bibcode:2011ApJS..197...19K. doi:10.1088/0067-0049/197/2/19.  edit
  2. ^ a b c d e f g h i j k l m n o p q r s t Beichman, C.; Gelino, Christopher R.; Kirkpatrick, J. Davy; Barman, Travis S.; Marsh, Kenneth A.; Cushing, Michael C.; Wright, E. L. (2013). "The Coldest Brown Dwarf (or Free-floating Planet)?: The Y Dwarf WISE 1828+2650". The Astrophysical Journal 764 (1): 101. arXiv:1301.1669. Bibcode:2013ApJ...764..101B. doi:10.1088/0004-637X/764/1/101.  edit
  3. ^ a b c d e Dupuy, Trent J.; Kraus, Adam L. (2013). "Distances, Luminosities, and Temperatures of the Coldest Known Substellar Objects". arXiv:1309.1422v1 [astro-ph.SR]. Bibcode 2013arXiv1309.1422D.
  4. ^ a b c d e f g Cushing, Michael C.; Kirkpatrick, J. Davy; Gelino, Christopher R.; Griffith, Roger L.; Skrutskie, Michael F.; Mainzer, A.; Marsh, Kenneth A.; Beichman, Charles A.; Burgasser, Adam J.; Prato, Lisa A.; Simcoe, Robert A.; Marley, Mark S.; Saumon, D.; Freedman, Richard S.; Eisenhardt, Peter R.; Wright, Edward L. (2011). "The Discovery of Y Dwarfs using Data from the Wide-field Infrared Survey Explorer (WISE)". arXiv:1108.4678v1 [astro-ph.SR]. Bibcode 2011ApJ...743...50C. doi:10.1088/0004-637X/743/1/50. edit
  5. ^ Kirkpatrick, J. D.; Gelino, C. R.; Cushing, M. C.; Mace, G. N.; Griffith, R. L.; Skrutskie, M. F.; Marsh, K. A.; Wright, E. L.; Eisenhardt, P. R.; McLean, I. S.; Mainzer, A. K.; Burgasser, A. J.; Tinney, C. G.; Parker, S.; Salter, G. (2012). "Further Defining Spectral Type "Y" and Exploring the Low-mass End of the Field Brown Dwarf Mass Function". The Astrophysical Journal 753 (2): 156. arXiv:1205.2122. Bibcode:2012ApJ...753..156K. doi:10.1088/0004-637X/753/2/156.  edit

External links[edit]