  New images are presented of the supernova remnant (SNR) HB9 based on 408 MHz
and 1420 MHz continuum emission and HI-line emission data of the Canadian
Galactic Plane Survey (CGPS) by the Dominion Radio Astrophysical Observatory
(DRAO). Two methods of spectral index analysis for HB9 are presented and
compared: one removes compact sources at both frequencies but is limited to the
resolution of the 408 MHz image; the other removes compact sources only in the
1420 MHz image so is effective at higher spatial resolution. The second allows
more detailed spectral index variation studies than the first. The two T-T plot
methods and new integrated flux densities give spectral index
(S_{\nu}\propto\nu^{-alpha}) for the whole of HB9 of 0.48+-0.03; and
0.47+-0.06, respectively. These are lower than previous spectral index for HB9
(alpha=0.61). Spatial variations of spectral index are derived using the second
method and yield a steeper spectral index for interior regions than for the
rim. This can be explained by a standard curved interstellar electron energy
spectrum combined with lower interior magnetic field compared to that near the
outer shock, which results in a larger proportion of steep spectrum emission
for lines-of-sight through the central body of the SNR. HI observations show
structures probably associated with the SNR in the radial velocity range -3 to
-9 km/s and suggest a distance of 0.8+-0.4 kpc for the SNR. This is consistent
with the distance to the radio pulsar 0458+46, offset from the center of HB9 by
23'. However the pulsar spindown and kinematic ages are significantly greater
than estimates of the SNR age: the Sedov age for HB9 is 6600 yr and the
evaporative cloud model yields ages of 4000-7,000 yr.
