[Shark Bait (Stu)]

Originally Posted by malclocke

I'm certainly no expert but I'll explain it as I understand. B and V refers to different types of photometric filters, Blue and Visual (green) respectively. Others are available, for example U (ultraviolet) and R (red). See http://en.wikipedia.org/wiki/Photometric_system

Photometric magnitudes are generally measured through these filters, so the filter type will be listed with the magnitude reading.

B-V is simply the magnitude from the B filter minus the magnitude from the V filter. The B-V colour index gives a crude measure of the colour of the star, the higher the number the redder the star. So when Jon says 'B-V increasing' he is effectively saying the star is getting redder.

Thanks for the info Malc. Am I correct in saying calibrated photometry can be used to provide an accurate apparent magnitude of the nova when all of the filter (passband) readouts are combined?

I have just been outside to check in on this nova. From my location it is hard to see with the unaided eye but easy in bino's. Observing visually through 7x50's it still appears to be around Mag 4.5 with no obvious colour. Nearby stars HIP64425 apparent Mag 4.56, HIP65271 apparen Mag 4.50 and TYC8661-2282-1 apparent Mag 4.90 were used to compare apparent magnitudes.