It has recently been suggested that the radio spectrum of the Galactic
supernova remnant HB 3 shows flattening at higher frequencies (above about 1
GHz). Here I review the radio spectrum of HB 3, noting the difficulties in
deriving accurate flux densities for this remnant, particularly at high
frequencies, due to the proximity of bright, thermal emission from W3 and its
surroundings. A flux density for HB 3 at 2695 MHz is derived from Effelsberg
survey data. The spectrum of HB 3 is well represented by a simple power-law
spectrum from 22 to 2695 MHz, with a spectral index of 0.56 +/- 0.03. It is
concluded that contamination with thermal emission from adjacent regions is the
cause for the reported spectral flattening of HB 3.Comment: Accepted for publication by the Bulletin of the Astronomical Society
of Indi