The multiple system HR8799 was the first multiple system discovered using direct imaging. In addition, this system has a debris disk with two rings, the central star has surface chemical peculiarities (lambda bootis phenomenon), and it is also a pulsating star (a gamma doradus pulsating star with three observed frequencies). All this makes HR8799 a very interesting object. There are several uncertainties to be studied in this system: 1) What is the internal metallicity of the star?, 2) What are the masses of the orbiting objects?, 3) Is there any relation between the density of the debris disk and the presence of orbiting objects?, 4) What is the dynamical configuration of the system?, etc. To answer all these questions, the mass, age and metallicity of the central star play a major role. In this presentation I review what we know about these quantities and what techniques can be used to obtain the most accurate values of these stellar physical characteristics possible.