Baryon magnetic moments in chiral perturbation theory

We consider the chiral expansion of the octet baryon magnetic moments in heavy baryon chiral perturbation theory including ``all'' terms which are of order q^4. These terms are formally of quadratic order in the quark masses. We show that despite the large non-analytic quark mass corrections to the Coleman-Glashow relations at order q^3, including all analytic and non-analytic corrections at order q^4, which in total are of moderate size, allows for a perfect fit to the measured magnetic moments. In this scheme, the $\Lambda \Sigma^0$ transition moment is predicted to be $\mu_{\Lambda \Sigma^0} = (1.51 \pm 0.01) \mu_N$.