Temporal spectral astronomy or time resolved astronomy is the study of astrophysical phenomena that show spectral variability on very short timescales. These timescales are often too short to be resolved by current astronomical equipment. The lack of detailed observations in this area keeps important theoretical descriptions of astronomical events unclear or incomplete. To resolve this, instruments with very high spectral resolution and fast read-out speeds are needed. Photonic devices such as fibre Bragg gratings (FBGs) offer potential advantages. The use of Bragg gratings in optical fibres allows for very high spectral resolution and the stability and precision needed for the observation of the fast variation of one particular spectral line, with the potential to observe multiple spectral lines at once. Here, we present the concept for a fibre Bragg grating based instrument specifically for temporal spectral astronomy and we discuss the different profiles of FBGs for such applications.