Thanks for showing us the very nice photometric data you have captured so far for Barnard’s star. We are looking for activity on the star which can be periodic (related to rotation of the star) e.g. if there are spots and also any random events such as flares. We are also looking for potential exoplanet transits which are periodic but of unknown period – as Barnard’s star is relatively quiet you should be able to see them with your data providing the transit is deep enough… So please observe when you can – the more you observe the more chance you have of catching something. As far as the Halpha goes please just use the R band magnitude for the comparison star C2 which is 11.30.