WISEPA J182831.08+265037.8
Coordinates: 18h 28m 31.10s, +26° 50′ 37.79″
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[ 1] |
Apparent magnitude (J (MKO filter system)) | 23.57 ± 0.35[ 1] |
Apparent magnitude (H (MKO filter system)) | 22.45 ± 0.08[ 1] |
Astrometry | |
Proper motion (μ) | RA: 954 ± 11[ 1] mas/yr Dec.: 153 ± 12.5[ 1] mas/yr |
Parallax (π) | 70 ± 14[ 1] mas |
Distance | approx. 47 ly (approx. 14 pc) |
Details | |
Mass | ~ 3—6 (0.5—20)[ 1] MJup |
Temperature | 250—400[ 1] K |
Age | ~ 2—4 (0.1—10)[ 1] Gyr |
Other designations | |
WISEPA J182831.08+265037.8 (designation is abbreviated to WISE 1828+2650) is a brown dwarf or free-floating planet[ 1] of spectral class >Y2,[ 1] located in constellation Lyra at approximately 47 light-years from Earth.[ 1] It is the "archetypal member" of the Y spectral class.[ 1]
History of observations
Discovery
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][ 1]
- 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.[ 1] These seven objects are also the faintest seven of 98 brown dwarfs, presented in Kirkpatrick et al. (2011).[ 1]
Distance
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.[ 1]
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 | [ 1] |
Beichman et al. (2013) | 90 ± 9.5[~ 2] | 11.2+1.3 −1.0 | 36.5+4.2 −3.3 | [ 1] |
Dupuy & Kraus (2013) | 70 ± 14[~ 3] | 14.3+3.6 −2.4 | 46.6+11.6 −7.8 | [ 1] |
Non-trigonometric distance estimates are marked in italic. The most precise estimate is marked in bold.
Proper motion
WISE 1828+2650 has proper motion of about 966 milliarcseconds per year.[ 1]
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 | [ 1] |
Dupuy & Kraus (2013) | 1034 ± 15 | 80.4 ± 0.9 | 1020 ± 15 | 173 ± 16 | [ 1] |
Non-trigonometric distance estimates are marked in italic. The best estimate is marked in bold.
Physical properties
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).[ 1] It has a temperature in the range 250—400 K[ 1] (-23—127 °C / -10—260 °F) (initially was estimated below 300 K[ 1] (about 27 °C / 80 °F)). It has been assigned the latest known spectral class (>Y2,[ 1] initially estimated as >Y0[ 1]).
Mass of WISE 1828+2650 is in the range 0.5—20 MJup for ages of 0.1—10 Gyr.[ 1]
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.[ 1][~ 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.[ 1]
Possible binarity
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.[ 1]
See also
The other six discoveries of brown dwarfs, published by Cushing et al. in 2011:[ 1]
- WISE 0148-7202 (T9.5)
- WISE 0410+1502 (Y0)
- WISE 1405+5534 (Y0 (pec?))
- WISE 1541-2250 (Y0.5)
- WISE 1738+2732 (Y0)
- WISE 2056+1459 (Y0)
Notes
- ↑ 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.
- ↑ According Dupuy & Kraus (2013), this measurement uncertainty is likely underestimated.
- ↑ Relative parallax.
- ↑ 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
- ↑ 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.
- ↑ 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.
- ↑ 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.
- ↑ 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.
- ↑ 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.
External links
- Choi, Charles Q. (August 26, 2011). "Y dwarf star? Because they're cool, that's Y!". Space.com. Retrieved August 31, 2011.
- NASA news release
- Science news
- Infrared image of WISE 1828+2650 at Astronomy Picture of the Day, 2011 August 30
- Solstation.com (New Objects within 20 light-years)
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