Hi David,
No I didn’t go to the expense of the calibration module,hence the use of the Balmer lines as you suggeted. Had another go at calibrating in BASS,but this time I subtracted the sky background leaving the profile for the galaxy rather noisey,but then I realised it would be because the captured spectrum isn’t as defined as that of a star..Doh!! Anyway I have uploaded the resulting profile showing both the A class star and the galaxy,the sodium line has shrunk and the Ha emission line has risen.
Regards
Alun