Hello I have questions related to the hipparcos catalogue. I like to know what kind of star-properties it is possible to extract from this catalogue. I was already at the hipparcos-website to try to figure it out myself, but as I am anything else than an expert on the matter, I got very confused about all the attributes in the catalogue. I hope someone here can help me out a little... As far as I know, I can get the star's distance and its luminosity and of course position from the catalogue. What I like to know is, can I get the following properties also? -Mass -Diameter -Star type (white dwarf, neutron star, red giant, multiple star system, ...) -temperature -velocity(transverse / radial) -age -... I know this is somewhat of a general question, but Im really out in the wind here, trying to get a basic Idea of the whole thing, on whats possible and whatnot. Also can I get everything I get out of the hipparcos catalogue out of the Tycho catalogue, only less accurate? Any help would be great, and really appreciated!