Comet /2011 Panstarrs
Thursday, March 21, 2013 at 12:49PM Frustrated by the fact that Panstarrs is behind a 100ft Oak tree in my garden I spent some time checking my plantarium software for its position. I notice that there are a number of other comets close to C/2011 L4 (Panstarrs). In fact there are two other Pannstarrs - these are C/2012 S4 (Panstarrs) and C/2012 V1 (Panstarrs). However V1 is approx magnitude 15 and S4 is approx magnitude 19! Bearing in mind that L4 is about magnitude 6 there is a difference of 13 magnitudes between it and S4 and as a difference of 5 magnitudes is a brightness difference of 100 that makes S4 unbelievably fainter! (A difference of 10 mags is 10000 X fainter, a 15 mag difference is 1 million times fainter -I will leave you to do the exact Maths (see my article in the Journal recently and spreadsheet if you want to work out the exact value if you are new to this). There are also other comets in the vicinity. In the chart below I have marked magnitudes on some of these.