Doradus. 2M0355 remains the brightest isolated low surface gravity L dwarf studied to date and will prove to be a useful comparative object in low-temperature atmosphere studies directly applicable to giant exoplanets.

Despite the spectral similarity to 2M1207b in $H$ and $K$, 2M0355 is substantially different from the planetary-mass object in $J$band. This, combined with the older age estimate for 2M0355, cause the temperature and mass of 2M0355 to remain ambiguous. Nevertheless, we can use the object’s absolute photometry and constrained age (assuming membership in AB Doradus) to estimate these key properties. Using the evolutionary tracks for young, low mass objects of @Baraffe02, we estimate an effective temperature of $/sim$1500 K and a mass of $/sim$13 M$_{Jup}$ for an age of 50 Myr (the lower limit for the age of AB Doradus). At the upper age limit for AB Doradus, $/sim$150 Myr, the mass of 2M0355 would be closer to $/sim$30 M$_{Jup}$. As a field object, the absolute magnitudes of 2M0355 correspond to an object of $\sim$70 M$_{Jup}$, slightly below hydrogen burning minimum mass.

![image](Kinematics1.eps){width=".55\hsize"}

[lcccrrrrrrrrrrr]{} \[tab:tab1\] CTIO 4M & ISPI & 30x2 & 5 & 2008 October 11 & 1.3 & $J$\
& & 10x4 & 5 & 2008 