LP 944-20
Coordinates: 
03h 39m 35.22s, −35° 25′ 44.09″
| Observation data Epoch J2000 Equinox J2000 |
|
|---|---|
| Constellation | Fornax |
| Right ascension | 03h 39m 35.220s[1] |
| Declination | –35° 25′ 44.09″[1] |
| Apparent magnitude (V) | 18.69[2] |
| Characteristics | |
| Spectral type | M9[1] |
| Apparent magnitude (B) | ~20.17[1] |
| Apparent magnitude (I) | ~13.288[1] |
| Apparent magnitude (J) | 10.725±0.021[1] |
| Apparent magnitude (H) | 10.017±0.021[1] |
| Apparent magnitude (K) | 9.548±0.023[1] |
| Astrometry | |
| Proper motion (μ) | RA: 317±60[1] mas/yr Dec.: 276±52[1] mas/yr |
| Parallax (π) | 155.89 ± 1.03[3][4]:{{{3}}} mas |
| Distance | 20.9 ± 0.1 ly (6.41 ± 0.04 pc) |
| Absolute magnitude (MV) | 20.02 |
| Details | |
| Mass | 0.07[2] M☉ |
| Other designations | |
|
LP 944-20,
SIPS J0339−3525, LEHPM 3451, 2MASSI J0339352−352544, [B2006] J033935.2−352544, APMPM J0340−3526, 2MASS J03393521−3525440, 2MASSW J0339352−352544, BRI B0337−3535, BRI 0337−3535, 2MUCD 10201 |
|
| Database references | |
| SIMBAD | data |
LP 944-20 is a dim brown dwarf of spectral class M9 located about 21 light-years from the Solar System in the constellation of Fornax. With a visual apparent magnitude of 18,[2] it has one of the dimmest visual magnitudes listed on the RECONS page.
On 15 December 1999 a flare was detected.[5]
Distance
The first parallax measurement from 1996 found that LP 944-20 (designated there as BRI 0337−3535) has a relative parallax of 
mas, and its correction from relative to absolute parallax (i.e. mean parallax of the reference frame stars) is 
mas. This yields an absolute parallax of 
mas, with a standard deviation (according to 
[6]) of 
mas, which corresponds to a distance of 5±0.1 pc, or 16.2±0.3 ly.[7] (The same values of absolute parallax and its standard deviation are in the RECONS' TOP100 list.[2][note 1]
A newer parallax, published in 2013, is 155.89±1.03 mas (6.41±0.04 pc or 20.92±0.14 ly).[3]
Lithium and clouds
Observations published in 2007 showed that the atmosphere of LP 944-20 contains much lithium and that it has dusty clouds.[8]
Notes
- ↑ In RECONS' TOP100 older versions the standard deviation value was 4.20 mas, not 4.21 mas.
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ 2.0 2.1 2.2 2.3 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ 3.0 3.1 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ http://www.solstation.com/stars/lp944-20.jpg
- ↑ Mean and Variance of Random Variables
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
