Saturated absorption spectroscopy, also known as Doppler-free spectroscopy, can be used to find the true frequency of an atomic transition without cooling a sample down to temperatures at which the Doppler broadening is minimal.
The low expansion velocity of SN2008ha resulted in relatively small Doppler broadening of spectral emission lines and this led to higher quality data.
Another way to measure the temperature is by relating the FWHM of the probed absorption line to the Doppler line width of the species at that temperature.
Doppler effect | Doppler radar | Doppler | doppler radar | doppler | Christian Doppler | Pulse-Doppler radar | Doppler broadening | Doppler Radar | Acoustic Doppler Current Profiler |