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[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) | 90 ± 9.5[2] mas |
| Distance | approx. 36 ly (approx. 11 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 (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 37 light-years from Earth.[2] It is the "archetypal member" of the Y spectral class.[3]
Contents |
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][3] 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][note 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.[3] This seven objects are also the faintest seven of 98 brown dwarfs, presented in Kirkpatrick et al. (2011).[1]
Distance [edit]
Trigonometric parallax of WISE 1828+2650 by Beichman et al., published in 2013, is 0.090 ± 0.0095 arcsecond, corresponding to a distance 11.2+1.3
−1.0 pc, or 36.5+4.2
−3.3 ly.[2]
Photometric distance estimate of this object, published in its discovery paper, was <9.4 pc (<30.7 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 |
[4] |
| Beichman et al. (2013) | 90 ± 9.5 | 11.2+1.3 −1.0 |
36.5+4.2 −3.3 |
[2] |
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] |
The most accurate estimates are marked in bold.
Physical properties [edit]
WISE 1828+2650 may be the coolest currently known brown dwarf or the first example of free-floating planet (it is not currently known if it 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[3] (about 27 °C / 80 °F)). It has been assigned the latest known spectral class (>Y2,[2] initially estimated as >Y0[3]).
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][note 2]
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]
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:[3]
- 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 [edit]
- ^ 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.
- ^ 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]
- ^ a b c d e f g h i j k l m n 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.
- ^ a b c d e f g h i j k l m n o p q r s t u v w Beichman, Charles A.; 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". arXiv:1301.1669v1 [astro-ph.SR]. Bibcode 2013arXiv1301.1669B.
- ^ 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.
- ^ Kirkpatrick, J. Davy; Gelino, Christopher R.; Cushing, Michael C.; Mace, Gregory N.; Griffith, Roger L.; Skrutskie, Michael F.; Marsh, Kenneth A.; Wright, Edward L.; Eisenhardt, Peter R.; McLean, Ian S.; Mainzer, Amanda K.; Burgasser, Adam J.; Tinney, C. G.; Parker, Stephen; Salter, Graeme (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.
External links [edit]
- 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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