Lambda point in the 4He-Vycor System:: A test of hyperuniversality

We have performed a high resolution specific heat measurement on He-4 completely filling the pores of Vycor glass. Within 10 mK of the superfluid transition we observe a peak in the heat capacity which is only 0.02% the size of the background. The peak is fitted with a rounded version of the "logarithmic singularity" observed in bulk He-4. This adds strong support to the suggestion that disorder imposed by the Vycor is irrelevant to the 3DXY superfluid phase transition. The size of the peak, while in agreement with that found in other experiments in dilute superfluid 4He, is considerably larger than that predicted by the theory of hyperuniversality.