C © Owned by the authors, published by EDP Sciences, 2013 The angular momentum of isolated white dwarfs

Abstract. This is a very brief report on an ongoing program aimed at mapping the internal rotation profiles of stars through asteroseismology. Three years ago, we developed and applied successfully a new technique to the pulsating GW Vir white dwarf PG 1159−035, and were able to infer that it rotates very slowly and rigidly over some 99 % of its mass. We applied the same approach to the three other GW Vir pulsators with available rotational splitting data, and found similar results. We discuss the implications of these findings on the question of the angular momentum of white dwarfs resulting from single star evolution. 1. ASTROPHYSICAL CONTEXT White dwarf stars represent the final phase of the evolution of some 95−97 % of all stars. If stars were to keep their angular momentum throughout their evolution, their white dwarf descendants, due to their compact nature, would all rotate relatively rapidly, with periods of order of seconds. Observations of their photospheres show, however, that they rotate much slower (at least superficially), with periods (measured mostly through spectroscopy and polarimetry) ranging from a few hours to tens of years. While it is widely believed that most of the angular momentum of an isolated star is lost during important mass loss episodes as it goes through the red giant phases of its evolution, current observations have been unable to reveal how rotation varies with depth in a white dwarf. In particular, one could never exclud