# LP 944-020

LP 944-020
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) 201.40 ± 4.21[3] mas
Distance 16.2 ± 0.3 ly
(5.0 ± 0.1 pc)
Absolute magnitude (MV) 20.02
Details
Mass 0.07[2] M
Other designations
SIPS J0339-3525, LEHPM 3451,
2MASSI J0339352-352544,
[B2006] J033935.2-352544,
APMPM J0340-3526, LP 944-20,
2MASSW J0339352-352544,
BRI B0337-3535,
2MASS J03393521-3525440, 2MUCD 10201
Database references

LP 944-020 is a dim brown dwarf of spectral class M9, located about 16 light-years distant 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.

## Distance

According C. G. Tinney's 1996 paper "CCD astrometry of southern very low-mass stars",[3] LP 944-020 (designated there as BRI 0337-3535) has relative parallax $\pi_r=200.0\pm4.2$ mas, and correction from relative to absolute parallax (i. e. mean parallax of the reference frame stars) $\pi_{ref}=1.4\pm0.3$ mas. This yields absolute parallax $\pi_r+\pi_{ref}=200.0+1.4=201.4$ mas, and standard deviation of absolute parallax (according formula $\sigma_{X+Y}^2=\sigma_X^2+\sigma_Y^2$[4]) $\sqrt{\sigma_{\pi_r}^2+\sigma_{\pi_{ref}}^2}=\sqrt{4.2^2+0.3^2}=4.21$ mas, and this corresponds to a distance of $5\pm0.1$ pc, or $16.2\pm0.3$ ly. (The same values of absolute parallax and its standard deviation are in RECONS' TOP100 list,[2] which is referenced to the aforementioned Tinney's article.)[note 1]

## Lithium and clouds

Observations published in 2007 showed that this object has an atmosphere high in lithium that also features dusty clouds.[5]