Supernovae+Calibration

**CCD camera**
Current CCD camera is a MX716 CCD from Starlight Xpress. QE and Spectral response can be seen in the link given.

**Calibration information**
Things to sort out...CBAT comment:-
 * Were those unfiltered CCD images?
 * What was the limiting magnitude of your images?
 * How many images did you take?
 * Did you measure a position or an offset?
 * Do you have reference images taken before the supernova appeared to compare it to, and if so, what are the dates and limiting magnitudes
 * What are the bandpasses of the images?

Notes form Ian:-
Dave, I have done some reading... You will need a V band filter... to be able to determine the apparent visual magnitude. The IR CUT filter will be too broad. You do however only need the one filter The V band filters cut between 500 and 700nm I have a green filter i will use the spectrograph to analyse the spectral response of this and the other filters i have... Below are the curves of the Johnson/Cousins/Bessel filter sets I have their papers if you are really interested Johnson was a bit of a dude trying to obtain absolute flux data in the 1960s My formula works for flux in any band and so should have worked on you image ... but you will have flux from outside the V band wavelengths that means that my calculated results will not compare well to the data published as 'apparent visual magnitude'... as these would have been obtained with a V-Band filter. I have included the text that enlightened me... Hope this helps Ian Each difference of 1 magnitude corresponds approximately to a ratio of 2.5 in brightness. This was precisely quantified so that a difference of 5 magnitudes was set to be precisely a factor of 100. This meant that a difference of 1 magnitude corresponds to a factor of 2.512 in brightness since (2.512 × 2.512 × 2.512 × 2.512 × 2.512) = (2.512)5 = 100. The difference in magnitudes of two stars may be expressed in the form of an equation: (m1 − m2) = –2.5 log(b1/b2) where m1 and m2 are the apparent magnitudes of stars 1 and 2, and b1 and b2 are the apparent brightnesses of stars 1 and 2. The brightnesses are defined by the flux density F, although they can, in this equation, be measured in any units (e.g. output signal from a measuring device) because the units cancel in the ratio b1/b2. If the flux densities of the stars are measured in the V band, then b1 and b2 correspond to measurements of FV for the two stars. m1 and m2 are then called apparent visual magnitudes and denoted mV or simply V.