WISE 1217+1626
Coordinates: 12h 17m 56.96s, +16° 26′ 39.98″
Observation data Epoch MJD 55549.01[1]:{{{3}}} Equinox J2000[1]:{{{3}}} |
|
---|---|
Constellation | Coma Berenices |
Right ascension | 12h 17m 56.96s[1]:{{{3}}} |
Declination | 16° 26′ 39.98″[1]:{{{3}}} |
Characteristics
|
|
Whole system | |
Apparent magnitude (Y (MKO filter system) | 18.38±0.04[2]:{{{3}}} |
Apparent magnitude (J (2MASS filter system) | >18.52[1]:{{{3}}} |
Apparent magnitude (J (MKO filter system) | 17.83±0.02[1]:{{{3}}}[2]:{{{3}}} |
Apparent magnitude (H (2MASS filter system) | >17.50[1]:{{{3}}} |
Apparent magnitude (H (MKO filter system) | 18.18±0.05[1]:{{{3}}}[2]:{{{3}}} |
Apparent magnitude (KS (2MASS filter system) | >16.64[1]:{{{3}}} |
Apparent magnitude (K (MKO filter system) | 18.80±0.04[2]:{{{3}}} |
Component A | |
Spectral type | T9[2]:{{{3}}} |
Apparent magnitude (Y (MKO filter system) | 18.59±0.04[2]:{{{3}}} |
Apparent magnitude (J (MKO filter system) | 17.98±0.02[2]:{{{3}}} |
Apparent magnitude (H (MKO filter system) | 18.31±0.05[2]:{{{3}}} |
Apparent magnitude (K (MKO filter system) | 18.94±0.04[2]:{{{3}}} |
Component B | |
Spectral type | Y0[2]:{{{3}}} |
Apparent magnitude (Y (MKO filter system) | 20.26±0.04[2]:{{{3}}} |
Apparent magnitude (J (MKO filter system) | 20.08±0.03[2]:{{{3}}} |
Apparent magnitude (H (MKO filter system) | 20.51±0.06[2]:{{{3}}} |
Apparent magnitude (K (MKO filter system) | 21.10±0.12[2]:{{{3}}} |
Astrometry | |
Proper motion (μ) | RA: 786±42[3]:{{{3}}} mas/yr Dec.: −1224±27[3]:{{{3}}} mas/yr |
Parallax (π) | 99 ± 16[3]:{{{3}}} mas |
Distance | approx. 33 ly (approx. 10 pc) |
Orbit[2]:{{{3}}} | |
Primary | A |
Companion | B |
Period (P) | 120+220 −30—210+380 −50 yr |
Details | |
Component A | |
Mass | (11.5±1.1)—(35±3)[2]:{{{3}}} MJup |
Luminosity (bolometric) | 10−5.95 ± 0.18[2]:{{{3}}} L☉ |
Surface gravity (log g) | (4.39±0.03)—(5.07±0.05)[2]:{{{3}}} cgs |
Temperature | (490±30)—(660±40)[2]:{{{3}}} K |
Component B | |
Mass | (5.5±1.2)—(20±2)[2]:{{{3}}} MJup |
Luminosity (bolometric) | 10−6.79 ± 0.18[2]:{{{3}}} L☉ |
Surface gravity (log g) | (4.07±0.10)—(4.77±0.05)[2]:{{{3}}} cgs |
Temperature | (350±40)—(470±30)[2]:{{{3}}} K |
Position (relative to A) | |
Component | B |
Epoch of observation | UT 2012 January 29 |
Angular distance | 758.2±1.4 mas [2]:{{{3}}} |
Position angle | 14.50±0.13° [2]:{{{3}}} |
Observed separation (projected) |
~ 8 AU [2]:{{{3}}} |
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]:{{{3}}} located in constellation Coma Berenices at approximately 33 light-years from Earth.[3]:{{{3}}}
Contents
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]:{{{3}}}[~ 1]
Initial estimate of spectral type
Initial estimate of WISE 1217+1626' spectral type (before discovery of its binarity) was T9[1]:{{{3}}}[4]:{{{3}}} (the same as the component's A type estimate made after this discovery).[2]:{{{3}}}
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]:{{{3}}}
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]:{{{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]:{{{3}}} | |
Kirkpatrick et al. (2012) (not assuming binarity) |
~7.1 | ~23.2 | [4]:{{{3}}} | |
Liu et al. (2012) | 10.5 ± 1.7 | 34.2 ± 5.5 | [2]:{{{3}}} | |
Dupuy & Kraus (2013) | 99 ± 16[~ 2] | 10.1+1.9 −1.4 |
32.9+6.4 −4.6 |
[3]:{{{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]:{{{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 | 935±269 | −1497±279 | [1]:{{{3}}} |
Dupuy & Kraus (2013) | 1455±38 | 147.3±1.3 | 786±42 | −1224±27 | [3]:{{{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]:{{{3}}}
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) | 11.5±1.1 | 490±30 | 4.39±0.03 | |
B (for 1 Gyr) | 7.4±0.5 | 381±13 | 4.18±0.03 | 210+370 −50 |
A (for 5 Gyr) | 29±3 | 530±30 | 4.95±0.05 | |
B (for 5 Gyr) | 18.4±1.0 | 402±11 | 4.68±0.03 | 130+230 −30 |
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) | 14.4±1.8 | 610±40 | 4.54±0.07 | |
B (for 1 Gyr) | 35±3 | 430±30 | 4.27±0.05 | 190+340 −50 |
A (for 5 Gyr) | 8.3±0.9 | 660±40 | 5.07±0.05 | |
B (for 5 Gyr) | 20±2 | 470±30 | 4.77±0.05 | 120+220 −30 |
From Lyon/COND models and Lbol:
Component and assumed age |
Mass, MJup |
Teff, K |
log g, cm/s2 |
P, yr |
---|---|---|---|---|
A (for 1 Gyr) | 13±3 | 580±70 | 4.47±0.10 | |
B (for 1 Gyr) | 5.5±1.2 | 350±40 | 4.07±0.10 | 210+380 −50 |
A (for 5 Gyr) | 33±5 | 630±70 | 5.04±0.09 | |
B (for 5 Gyr) | 13±3 | 370±50 | 4.54±0.11 | 130+240 −30 |
See also
The other two brown dwarf binary systems, observed by Liu et al. with Keck II LGS-AO in 2012:[2]:{{{3}}}
- 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
- ↑ 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 1.11 1.12 1.13 1.14 1.15 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ 2.00 2.01 2.02 2.03 2.04 2.05 2.06 2.07 2.08 2.09 2.10 2.11 2.12 2.13 2.14 2.15 2.16 2.17 2.18 2.19 2.20 2.21 2.22 2.23 2.24 2.25 2.26 2.27 2.28 2.29 2.30 2.31 2.32 2.33 2.34 2.35 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ 4.0 4.1 Lua error in package.lua at line 80: module 'strict' not found.