The paper ‘Magnetars: super(ficially) hot and super(fluid) cool’ was published in Mon. Not. R. Astron. Soc. 422, 2632–2641 (2012). An error in the original work of van Riper (1991) was reproduced in our paper. Equations (10) and (11) for the ion heat capacity should read
In equation (10), the expression for Cion in the range 1 < Γc ≤ 150 is simply a smooth interpolation between the expressions in the range Γc ≤ 1 and Γc > 150. In equation (11), the value of 0.4 for the range is needed in order for fD(T/TD) to be smooth.
The remainder of the paper remains unaffected by these corrections since the primary effect of the ion heat capacity is on the thermal relaxation time of the crust, which is not the concern of our paper. We note that we have subsequently implemented more accurate ion and electron heat capacities from Potekhin & Chabrier (2010).