SCR 1845-6357
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SCR 1845-6357, right bottom
Three-colour image of SCR1845-6357AB generated from the SDI filter images (blue=1.575 micrometre, green=1.600 micrometre, red=1.625 micrometre). Because the T-dwarf fades away towards the longer wavelengths, it appears quite blue in this image. It is roughly 50 times fainter than the star and is separated from it by an angle of 1.17 arcsecond on the sky (4.5 times the Earth-Sun distance).
SCR 1845-6357 is a binary system, about 12.6 light-years away in the constellation Pavo. The primary is a faint red dwarf. It has a brown dwarf companion.
SCR 1845-6357 A
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Pavo |
| Right ascension | 18h 45m 05.26s[1] |
| Declination | −63° 57′ 47.8″[1] |
| Apparent magnitude (V) | 17.4[2] |
| Characteristics | |
| Spectral type | M8.5[3] |
| Astrometry | |
| Proper motion (μ) | RA: 2444[2] mas/yr Dec.: 696[2] mas/yr |
| Parallax (π) | 259.45 ± 1.11[1] mas |
| Distance | 12.57 ± 0.05 ly (3.85 ± 0.02 pc) |
| Details | |
| Mass | 0.07 [4] M☉ |
| Radius | 0.096 R☉ |
| Luminosity | 0.0004 L☉ |
| Temperature | 2600–2700[3] K |
| Other designations | |
The primary, SCR 1845-6357A, is a faint (apparent magnitude 17.4)[2] red dwarf star with a mass of about 7% of the Sun's. However, the measurements are still preliminary and are subject to change.[4]
SCR 1845-6357 B
| Position (relative to A) | |
|---|---|
| Epoch of observation | J2006.3 |
| Angular distance | 1.064 ± 0.004″ [3] |
| Position angle | 177.2 ± 0.06° [3] |
| Observed separation (projected) | 4.10 ± 0.04 AU [5] |
| Characteristics | |
| Spectral type | T6 [3] |
| Apparent magnitude (J) | 13.26[6] |
| Details | |
| Mass | 0.04 to 0.05 [3] M☉ |
| Surface gravity (log g) | 5.1 [3] cgs |
| Temperature | 950 [3] K |
| Age | 1.8·109 to 3.1·109 [3] years |
| Other designations | |
This star has been found to possess a brown dwarf companion, designated SCR 1845-6357B. The companion, classified as a T-dwarf, has an observed projected distance of 4.1 AU, an estimated mass between 40 and 50 times the mass of Jupiter, and an estimated effective temperature of 950 K.[3][5] The brown dwarf has a near-IR J band magnitude of 13.26.[6]
Distance
SCR 1845-6357 distance estimates
| Source | Parallax, mas | Distance, pc | Distance, ly | Distance, Pm | Ref. |
|---|---|---|---|---|---|
| Deacon et al. (2005) | 282±23 | 3.55+0.31 −0.27 |
11.6+1 −0.9 |
109.4+9.7 −8.3 |
[8] |
| Henry et al. (2006) | 259.45±1.11 | 3.854+0.017 −0.016 |
12.57±0.05 | 118.9±0.5 | [1][9] |
| RECONS TOP100 (2012) | 259.50±1.11[note 1] | 3.854+0.017 −0.016 |
12.57±0.05 | 118.9±0.5 | [10] |
Non-trigonometric distance estimates are marked in italic. The most precise estimate is marked in bold.
References
- ↑ 1.0 1.1 1.2 1.3 Henry, T. J.; Jao, Wei-Chun; Subasavage, John P.; Beaulieu, Thomas D.; Ianna, Philip A.; Costa, Edgardo; Méndez, René A. (2006). "The Solar Neighborhood. XVII. Parallax Results from the CTIOPI 0.9 m Program: 20 New Members of the RECONS 10 Parsec Sample". The Astronomical Journal 132 (6): 2360–2371. arXiv:astro-ph/0608230. Bibcode:2006AJ....132.2360H. doi:10.1086/508233.
- ↑ 2.0 2.1 2.2 2.3 2.4 DENIS-P J184504.9-635747, entry, SIMBAD. Accessed on line June 17, 2008.
- ↑ 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 The very nearby M/T dwarf binary SCR 1845-6357, Markus Kasper, Beth A. Biller, Adam Burrows, Wolfgang Brandner, Jano Budaj, and Laird M. Close, Astronomy and Astrophysics 471, #2 (August 2007), pp.655–659. Bibcode: 2007A&A...471..655K. doi:10.1051/0004-6361:20077881.
- ↑ 4.0 4.1 Research Consortium On Nearby Stars, Georgia State University (January 1, 2008). "THE ONE HUNDRED NEAREST STAR SYSTEMS". RECONS. Retrieved June 17, 2008.
- ↑ 5.0 5.1 Observed projected distance computed from parallax and observed angular distance.
- ↑ 6.0 6.1 Chris Gelino, Davy Kirkpatrick, Adam Burgasser. "DwarfArchives.org: Photometry, spectroscopy, and astrometry of M, L, and T dwarfs". caltech.edu. Retrieved 2012-06-10. (main page)
- ↑ SCR J1845-6357B, entry, SIMBAD. Accessed on line June 17, 2008.
- ↑ Deacon, Niall R.; Hambly, Nigel C.; Henry, Todd J.; Subasavage, John P.; Brown, Misty A.; Jao, Wei-Chun (2005). "The Solar Neighborhood. XI. The Trigonometric Parallax of SCR 1845-6357". The Astronomical Journal 129 (1): 409–412. arXiv:astro-ph/0409582. Bibcode:2005AJ....129..409D. doi:10.1086/426330.
- ↑ Faherty, Jacqueline K.; Burgasser, Adam J.; Walter, Frederick M.; Van der Bliek, Nicole; Shara, Michael M.; Cruz, Kelle L.; West, Andrew A.; Vrba, Frederick J.; Anglada-Escud, Guillem (2012). "The Brown Dwarf Kinematics Project (BDKP). III. Parallaxes for 70 Ultracool Dwarfs". The Astrophysical Journal 752 (1): 56. arXiv:1203.5543. Bibcode:2012ApJ...752...56F. doi:10.1088/0004-637X/752/1/56.
- ↑ "RECONS TOP100". THE ONE HUNDRED NEAREST STAR SYSTEMS brought to you by RECONS (Research Consortium On Nearby Stars). 2012. Retrieved 2014-10-22.
- Hambly, Nigel C.; Henry, Todd J.; Subasavage, John P.; Brown, Misty A.; Jao, Wei-Chun (2004). "The Solar Neighborhood. VIII. Discovery of New High Proper Motion Nearby Stars Using the SuperCOSMOS Sky Survey". The Astronomical Journal 128 (1): 437–447. arXiv:astro-ph/0404265. Bibcode:2004AJ....128..437H. doi:10.1086/421748.
- B.A. Biller et al., 2006, "Discovery of a Brown Dwarf Very Close to the Sun: A Methane-rich Brown Dwarf Companion to the Low-Mass Star SCR 1845-6357", Astrophysical Journal Letters.
Notes
- ↑ Weighted parallax based on parallaxes from Deacon et al. (2005) and Henry et al. (2006).
External links
- New Objects within 20 light-years at SolStation.
- SCR 1845-6357
See also
- OTS 44
- Cha 110913-773444
- List of nearest stars
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