2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/187953In this letter we dynamically determine the quadrupole mass moment Q of the magnetic white dwarf WD 0137-349 by analyzing the period of the recently discovered brown dwarf moving around it in a close 2-hr orbit. It turns out that a purely Newtonian model for the orbit of WD 0137-349B, assumed circular and equatorial, is adequate, given the present-day accuracy in knowing the orbital parameters of such a binary system. Our result is Q=(-1.4615 +/- 0.9004) 10^47 kg m^2 for i=35 deg. It is able to accommodate the 3-sigma significant discrepancy of (1.0 +/- 0.3) 10^-8 s^-2 between the inverse square of the phenomenologically determined orbital period and the inverse square of the calculated Keplerian one. The impact of i, for which a range Delta i of possible values close to 35 deg is considered, is investigated as well.LaTex2e, 8 pages, no figures, 1 table, 23 references. Discussion on the impact of the inclination added. Thanks to J. Katz. More details on the significant 3-sigma discrepancy between the Keplerian and the phenomenologically measured period added. Two references added. Final version to appear in Astrophysics and Space Science, including the proofs correctionsGeneral Relativity and Quantum CosmologyAstrophysicsNuclear TheorySpace Physicstext