Abstract

We have determined the proper motion of the Large Magellanic Cloud (LMC) relative to a background quasistellar object, using observations carried out in seven epochs (six years of base time). Our proper motion value agrees well with most results obtained by other authors and indicates that the LMC is not a member of a proposed stream of galaxies with similar orbits around our galaxy. Using published values of the radial velocity for the center of the LMC, in combination with the transverse velocity vector derived from our measured proper motion, we have calculated the absolute space velocity of the LMC. This value, along with some assumptions regarding the mass distribution of the Galaxy, has in turn been used to calculate the mass of the latter. This work is part of a program to study the space motion of the Magellanic Clouds system and its relationship to the Milky Way (MW). This knowledge is essential to understand the nature, origin and evolution of this system as well as the origin and evolution of the outer parts of the MW. © 2009: Instituto de Astronomía, UNAM.