Abstract
The photographic subtraction formula expressing the ‘Doppler signal’ in terms of line-of-sight velocity is rederived and the conditions governing its validity are carefully stated. By appealing to the observed profiles of individual bright and dark mottles it is shown that, in the case of Hα observations of the quiet chromosphere, two essential conditions are violated.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have