WISE 0458+6434
Coordinates: 04h 58m 53.93s, +64° 34′ 52.72″
Observation data Epoch MJD 55453.42[1]:{{{3}}} Equinox J2000[1]:{{{3}}} |
|
---|---|
Constellation | Camelopardalis |
Right ascension | 04h 58m 53.93s[1]:{{{3}}} |
Declination | 64° 34′ 52.72″[1]:{{{3}}} |
Characteristics
|
|
Whole system | |
Apparent magnitude (Y (FanCam)) | 18.34 ± 0.07[2]:{{{3}}} |
Apparent magnitude (J (2MASS filter system)) | 17.47 ± 0.05[1]:{{{3}}} |
Apparent magnitude (H (2MASS filter system)) | 17.41 ± 0.06[1]:{{{3}}} |
Component A | |
Spectral type | T8.5[3]:{{{3}}}[4]:{{{3}}}[5]:{{{3}}} |
Apparent magnitude (J (MKO filter system)) | 17.50 ± 0.07[4]:{{{3}}} |
Apparent magnitude (H (MKO filter system)) | 17.77 ± 0.11[4]:{{{3}}} |
Component B | |
Spectral type | T9.5[4]:{{{3}}}[5]:{{{3}}} |
Apparent magnitude (J (MKO filter system)) | 18.48 ± 0.07[4]:{{{3}}} |
Apparent magnitude (H (MKO filter system)) | 18.79 ± 0.11[4]:{{{3}}} |
Astrometry | |
Proper motion (μ) | RA: 136 ± 45[6]:{{{3}}} mas/yr Dec.: 317 ± 22[6]:{{{3}}} mas/yr |
Parallax (π) | 70 ± 19[6]:{{{3}}} mas |
Distance | approx. 50 ly (approx. 14 pc) |
Orbit[3]:{{{3}}} | |
Primary | A |
Companion | B |
Period (P) | ~70[~ 1]:{{{3}}} yr |
Details | |
Component A | |
Mass | 15[3]:{{{3}}}[~ 1]:{{{3}}} MJup |
Surface gravity (log g) | 5.0—5.5[2]:{{{3}}}[~ 2]:{{{3}}} cgs |
Temperature | 600[3]:{{{3}}}[~ 1]:{{{3}}} K |
Metallicity | 0 ([Fe/H])[2]:{{{3}}}[~ 2]:{{{3}}} |
Component B | |
Mass | 10[3]:{{{3}}}[~ 1]:{{{3}}} MJup |
Temperature | 500[3]:{{{3}}}[~ 1]:{{{3}}} K |
Position (relative to A) | |
Component | B |
Epoch of observation | UT 2011 August 29 |
Angular distance | 455.1 ± 4.2 mas [4]:{{{3}}} |
Position angle | 322.9 ± 0.4° [4]:{{{3}}} |
Observed separation (projected) |
5 ± 0.4 AU [3]:{{{3}}} |
Other designations | |
WISEPC J045853.90+643451.9 (designation is abbreviated to WISE 0458+6434) is a binary system of two (A and B) ultracool brown dwarfs of spectral classes T8.5 and T9.5, respectively,[4]:{{{3}}}[5]:{{{3}}} located in constellation Camelopardalis at approximately 47 ly from Earth.[6]:{{{3}}}
Contents
History of observations
Discovery
WISE 0458+6434 A was discovered in 2010 by A. Mainzer 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 2010 Mainzer et al. had conducted follow-up observations of WISE 0458+6434:
- on 2010 March 17 (UT) YJH photometry with FanCam, an infrared imager operating at the University of Virginia’s Fan Mountain 31 in telescope;
- on 2010 March 19 (UT) 1.5—2.3 μm spectroscopy with LUCIFER near-infrared camera/spectrograph at the Large Binocular Telescope (LBT);
- on 2010 Sep 12 (UT) 0.8—2.5 μm spectroscopy with SpeX on the 3.0 m NASA Infrared Telescope Facility on Mauna Kea.
In early 2011 Mainzer et al. published a paper in The Astrophysical Journal, where they presented discovery of one new found by WISE brown dwarf — ultra-cool object WISE 0458+6434. This object became the first brown dwarf, found by WISE.[2]:{{{3}}}
Several months later, also in 2011, Kirkpatrick et al. published a paper in The Astrophysical Journal Supplement, where they presented characteristics of 104 first discovered by WISE brown dwarf systems — 98 new found systems and six systems, presented in published earlier papers (one in Mainzer et al. (2011), and five in Burgasser et al. (2011)[7]:{{{3}}}), among which also was WISE 0458+6434.[1]:{{{3}}}
Discovery of the component B
WISE 0458+6434 B was discovered in 2011 by Gelino et al., when they examined for binarity nine brown dwarfs using Laser Guide Star Adaptive Optics system (LGS-AO) on Keck II telescope on Mauna Kea; seven of these nine brown dwarfs were also newfound, and two were discovered before, including WISE 0458+6434. These observations had indicated that two of these nine brown dwarfs, including WISE 0458+6434, are binary. Angular separation of WISE 0458+6434 components was 80 mas.[3]:{{{3}}} Component B is also of late T-type — T9.5[4]:{{{3}}} (initially was estimated as T9).[3]:{{{3}}}
Distance
Currently the most accurate distance estimate of WISE 0458+6434 is a trigonometric parallax, measured using Spitzer Space Telescope and published in 2013 by Trent Dupuy and Adam Kraus: 0.070 ± 0.019 arcsec, corresponding to a distance 14.3+5.3
−3.0 pc, or 46.6+17.4
−9.9 ly.[6]:{{{3}}}
WISE 0458+6434 distance estimates
Source | Parallax, mas | Distance, pc | Distance, ly | Ref. |
---|---|---|---|---|
Mainzer et al. (2011) (spectrophotometric) |
6—8 | 19.6—26.1 | [2]:{{{3}}} | |
Mainzer et al. (2011) (photometric) |
9.0 ± 1.9 | 29.4 ± 6.2 | [2]:{{{3}}} | |
Mainzer et al. (2011) (combined) |
6—10 | 19.6—32.6 | [2]:{{{3}}}[8] | |
Kirkpatrick et al. (2011) (spectrophotometric, assuming a single source) |
~7.3 | ~23.8 | [1]:{{{3}}} | |
Gelino et al. (2011), (according Kirkpatrick et al. (2011), Appendix I.) |
12.3 ± 2.3 | 40.1 ± 7.5 | [1]:{{{3}}} | |
Gelino et al. (2011) | 10.5 ± 1.4 | 34.2 ± 4.6 | [3]:{{{3}}} | |
Burgasser et al. (2012) (component A) |
10.5 ± 1.8 | 34.2 ± 5.9 | [4]:{{{3}}} | |
Burgasser et al. (2012) (component B) |
11.2 ± 2.2 | 36.5 ± 7.2 | [4]:{{{3}}} | |
Burgasser et al. (2012) (combined A + B) |
~11 | ~35.9 | [5]:{{{3}}} | |
Dupuy & Kraus (2013) | 70 ± 19[~ 3]:{{{3}}} | 14.3+5.3 −3.0 |
46.6+17.4 −9.9 |
[6]:{{{3}}} |
Non-trigonometric distance estimates are marked in italic. The best estimate is marked in bold.
Space motion
WISE 0458+6434 has proper motion of about 347 milliarcseconds per year.[6]:{{{3}}}
WISE 0458+6434 proper motion estimates
Source | μ, mas/yr |
P. A., ° |
μRA, mas/yr |
μDEC, mas/yr |
Ref. |
---|---|---|---|---|---|
Mainzer et al. (2011) | 253 | 51 | 196.8 ± 29.1 | 159.3 ± 29.1 | [2]:{{{3}}} |
Kirkpatrick et al. (2011) | 219 | 57 | 185 ± 141 | 118 ± 149 | [1]:{{{3}}} |
Dupuy & Kraus (2013) | 347 ± 26 | 23 ± 7 | 136 ± 45 | 317 ± 22 | [6]:{{{3}}} |
The most accurate estimates are marked in bold.
Physical properties
The brown dwarfs' temperature estimates are 600 K, or 327 °C (A)[3]:{{{3}}} and 500 K, or 227 °C (B),[3]:{{{3}}} both cooler than Venus.
NH3 in the spectrum of component B
According proposed by Cushing et al. in 2011 T/Y transition standard,[9]:{{{3}}} WISE J0458+6434 B does not relate to Y-type. However, its spectrum has feature similar to those in the spectra of the Y0 dwarfs WISE 1405+5534 and WISE 1738+2732, which were tentatively attributed to NH3 (ammonia) absorption[4]:{{{3}}}[9]:{{{3}}} — a compelling evidence for NH3 absorption.[4]:{{{3}}}
See also
The other five earliest brown dwarf discoveries from data collected by WISE:
- published by Burgasser et al. (2011):[7]:{{{3}}}
- WISE 1617+1807 (T8, young and cloudy)
- WISE 1812+2721 (T8.5:, cloudless)
- WISE 2018-7423 (T7, possibly cloudy)
- WISE 2313-8037 (T8, also young and cloudy)
- WISE 2359-7335 (T5.5, cloudless)
The other eight objects, checked for binarity by Gelino et al. (2011) on Keck II:[3]:{{{3}}}
- binarity found:
- WISE 1841+7000 (T5 + T5, newfound)
- binarity not found:
- WISE 0750+2725 (T8.5, newfound[~ 4]:{{{3}}})
- WISE 1322–2340 (T8, newfound)
- WISE 1614+1739 (T9, newfound)
- WISE 1617+1807 (T8, discovered before by Burgasser et al. (2011)[7]:{{{3}}})
- WISE 1627+3255 (T6, newfound)
- WISE 1653+4444 (T8, newfound)
- WISE 1741+2553 (T9, newfound)
Notes
- ↑ 1.0 1.1 1.2 1.3 1.4 For an assumed system age of 1 Gyr.
- ↑ 2.0 2.1 This estimate is related to WISE 0458+6434 (not to component A individually), when its binarity was not yet uncovered.
- ↑ Relative parallax.
- ↑ Presented in Gelino et al. (2011), but this is not mentioned in Kirkpatrick et al. (2011) and Kirkpatrick et al. (2012) — according these two articles, the only discovery paper of WISE 0750+2725 is Kirkpatrick et al. (2011).
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 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ 3.00 3.01 3.02 3.03 3.04 3.05 3.06 3.07 3.08 3.09 3.10 3.11 3.12 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ 4.00 4.01 4.02 4.03 4.04 4.05 4.06 4.07 4.08 4.09 4.10 4.11 4.12 4.13 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ 5.0 5.1 5.2 5.3 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ 6.0 6.1 6.2 6.3 6.4 6.5 6.6 6.7 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ 7.0 7.1 7.2 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ WISE: First Ultra-cool Brown Dwarf
- ↑ 9.0 9.1 Lua error in package.lua at line 80: module 'strict' not found.