WISE 1217+1626
Coordinates: 12h 17m 56.96s, +16° 26′ 39.98″
Observation data Epoch MJD 55549.01[1] Equinox J2000[1] | |
---|---|
Constellation | Coma Berenices |
Right ascension | 12h 17m 56.96s[1] |
Declination | 16° 26′ 39.98″[1] |
Characteristics | |
Whole system | |
Apparent magnitude (Y (MKO filter system) | ±0.04 18.38[2] |
Apparent magnitude (J (2MASS filter system) | >18.52[1] |
Apparent magnitude (J (MKO filter system) | ±0.02 17.83[1][2] |
Apparent magnitude (H (2MASS filter system) | >17.50[1] |
Apparent magnitude (H (MKO filter system) | ±0.05 18.18[1][2] |
Apparent magnitude (KS (2MASS filter system) | >16.64[1] |
Apparent magnitude (K (MKO filter system) | ±0.04 18.80[2] |
Component A | |
Spectral type | T9[2] |
Apparent magnitude (Y (MKO filter system) | ±0.04 18.59[2] |
Apparent magnitude (J (MKO filter system) | ±0.02 17.98[2] |
Apparent magnitude (H (MKO filter system) | ±0.05 18.31[2] |
Apparent magnitude (K (MKO filter system) | ±0.04 18.94[2] |
Component B | |
Spectral type | Y0[2] |
Apparent magnitude (Y (MKO filter system) | ±0.04 20.26[2] |
Apparent magnitude (J (MKO filter system) | ±0.03 20.08[2] |
Apparent magnitude (H (MKO filter system) | ±0.06 20.51[2] |
Apparent magnitude (K (MKO filter system) | ±0.12 21.10[2] |
Astrometry | |
Proper motion (μ) | RA: ±42 786[3] mas/yr Dec.: ±27 −1224[3] mas/yr |
Parallax (π) | 99 ± 16[3] mas |
Distance | approx. 33 ly (approx. 10 pc) |
Orbit[2] | |
Primary | A |
Companion | B |
Period (P) | +220 −30— 120+380 −50 210yr |
Details | |
Component A | |
Mass | (±1.1)—( 11.5±3) 35[2] MJup |
Luminosity (bolometric) | 10−5.95 ± 0.18[2] L☉ |
Surface gravity (log g) | (±0.03)—( 4.39±0.05) 5.07[2] cgs |
Temperature | (±30)—( 490±40) 660[2] K |
Component B | |
Mass | (±1.2)—( 5.5±2) 20[2] MJup |
Luminosity (bolometric) | 10−6.79 ± 0.18[2] L☉ |
Surface gravity (log g) | (±0.10)—( 4.07±0.05) 4.77[2] cgs |
Temperature | (±40)—( 350±30) 470[2] K |
Position (relative to A) | |
Component | B |
Epoch of observation | UT 2012 January 29 |
Angular distance | ±1.4 758.2mas [2] |
Position angle | ±0.13 14.50° [2] |
Observed separation (projected) | ~ 8 AU [2] |
Other designations | |
WISEPC J121756.91+162640.2 (designation abbreviated to WISE 1217+1626, or WISE J1217+1626) is a binary brown dwarf system of spectral classes T9 + Y0,[2] located in constellation Coma Berenices at approximately 33 light-years from Earth.[3]
History of observations
Discovery
WISE 1217+1626 A was discovered in 2011 by J. Davy 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. In 2011 Kirkpatrick et al. published a paper in The Astrophysical Journal Supplement, where they 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 1217+1626.[1][~ 1]
Initial estimate of spectral type
Initial estimate of WISE 1217+1626' spectral type (before discovery of its binarity) was T9[1][4] (the same as the component's A type estimate made after this discovery).[2]
Discovery of component B
WISE 1217+1626 B was discovered in 2012 by Liu et al. with laser guide star (LGS) adaptive optics (AO) system of the 10-m Keck II Telescope on Mauna Kea, Hawaii, using infra-red camera NIRC2 (the observations were made on 2012 January 29 (UT)). On 2012 April 1 (UT) Liu et al. observed WISE J1217+1626AB using the near-IR camera NIRI on the Gemini-North 8.1-m telescope on Mauna Kea, Hawaii and the binary was marginally resolved. On 12 April 2012 (UT) they obtained resolved spectroscopy of WISE J1217+1626AB with the near-IR spectrograph NIRSPEC again on the Keck II Telescope. In 2012 Liu et al. published a paper in The Astrophysical Journal where they presented results of observations with Keck II LGS-AO of three brown dwarf binary systems, binarity of one of which was known before, and binarity of the other two, including WISE 1217+1626, was first presented in this paper.[2]
Distance
Currently the most accurate distance estimate of WISE 1217+1626 is a trigonometric parallax, measured using Spitzer Space Telescope and published in 2013 by Trent Dupuy and Adam Kraus: 0.099 ± 0.016 arcsec, corresponding to a distance 10.1+1.9
−1.4 pc, or 32.9+6.4
−4.6 ly.[3] In the estimates made before discovery of the component's B by Liu et al. in 2012 the binarity is not taken into account.
WISE 1217+1626 distance estimates
Source | Parallax, mas | Distance, pc | Distance, ly | Ref. |
---|---|---|---|---|
Kirkpatrick et al. (2011) (not assuming binarity) | ~6.7 | ~21.9 | [1] | |
Kirkpatrick et al. (2012) (not assuming binarity) | ~7.1 | ~23.2 | [4] | |
Liu et al. (2012) | 10.5 ± 1.7 | 34.2 ± 5.5 | [2] | |
Dupuy & Kraus (2013) | 99 ± 16[~ 2] | +1.9 −1.4 10.1 | +6.4 −4.6 32.9 | [3] |
Non-trigonometric distance estimates are marked in italic. The best estimate is marked in bold.
Space motion
WISE 1217+1626 has proper motion of about 1455 milliarcseconds per year.[3]
WISE 1217+1626 proper motion estimates
Source | μ, mas/yr | P. A., ° | μRA, mas/yr | μDEC, mas/yr | Ref. |
---|---|---|---|---|---|
Kirkpatrick et al. (2011) | 1765 | 148 | ±269 935 | ±279 −1497 | [1] |
Dupuy & Kraus (2013) | ±38 1455 | ±1.3 147.3 | ±42 786 | ±27 −1224 | [3] |
The most accurate estimates are marked in bold.
Physical properties
Using three models, Liu et al. calculated physical properties of WISE 1217+1626 components.[2]
From Burrows et al. (2003) models and M(J):
Component and assumed age | Mass, MJup | Teff, K | log g, cm/s2 | P, yr |
---|---|---|---|---|
A (for 1 Gyr) | ±1.1 11.5 | ±30 490 | ±0.03 4.39 | |
B (for 1 Gyr) | ±0.5 7.4 | ±13 381 | ±0.03 4.18 | +370 −50 210 |
A (for 5 Gyr) | ±3 29 | ±30 530 | ±0.05 4.95 | |
B (for 5 Gyr) | ±1.0 18.4 | ±11 402 | ±0.03 4.68 | +230 −30 130 |
From Lyon/COND models and M(J):
Component and assumed age | Mass, MJup | Teff, K | log g, cm/s2 | P, yr |
---|---|---|---|---|
A (for 1 Gyr) | ±1.8 14.4 | ±40 610 | ±0.07 4.54 | |
B (for 1 Gyr) | ±3 35 | ±30 430 | ±0.05 4.27 | +340 −50 190 |
A (for 5 Gyr) | ±0.9 8.3 | ±40 660 | ±0.05 5.07 | |
B (for 5 Gyr) | ±2 20 | ±30 470 | ±0.05 4.77 | +220 −30 120 |
From Lyon/COND models and Lbol:
Component and assumed age | Mass, MJup | Teff, K | log g, cm/s2 | P, yr |
---|---|---|---|---|
A (for 1 Gyr) | ±3 13 | ±70 580 | ±0.10 4.47 | |
B (for 1 Gyr) | ±1.2 5.5 | ±40 350 | ±0.10 4.07 | +380 −50 210 |
A (for 5 Gyr) | ±5 33 | ±70 630 | ±0.09 5.04 | |
B (for 5 Gyr) | ±3 13 | ±50 370 | ±0.11 4.54 | +240 −30 130 |
See also
The other two brown dwarf binary systems, observed by Liu et al. with Keck II LGS-AO in 2012:[2]
- WISE 1711+3500 (T8 + T9.5, binarity was newly discovered)
- CFBDSIR 1458+10 (T9 + Y0, binarity was known before)
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.
- ↑ Relative parallax.
References
- 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 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.
- 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 Liu, Michael C.; Dupuy, Trent J.; Bowler, Brendan P.; Leggett, S. K.; Best, William M. J. (2012). "Two Extraordinary Substellar Binaries at the T/Y Transition and the Y-band Fluxes of the Coolest Brown Dwarfs". The Astrophysical Journal. 758 (1): 57. arXiv:1206.4044. Bibcode:2012ApJ...758...57L. doi:10.1088/0004-637X/758/1/57.
- 1 2 3 4 5 6 7 8 Dupuy, T. J.; Kraus, A. L. (2013). "Distances, Luminosities, and Temperatures of the Coldest Known Substellar Objects". Science. 341 (6153): 1492. arXiv:1309.1422. Bibcode:2013Sci...341.1492D. doi:10.1126/science.1241917.
- 1 2 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.