Spectrum of the continuum emission from the HC H II region G24 A1. The points represent the measurements from our data (solid circles) and previously published data (empty circles), listed in Table 2. The error bars take into account both the errors given in the table and a conservative calibration uncertainty of 20%. The solid curve is the best fit to the data obtained for a spherical H II region, while the dashed curve is the best fit for a shell H II region with an inner radius 99% of the outer radius (see Sect. 4.1 for details on the model fit).