12p 20231207 0238 molason

12P/Pons-Brooks on the evening of 2023 December 7 was magnitude G=8.6 as calculated from 10x30 second green filter images with an 8' diameter aperture. Looking at Michael Jaeger's color image of 12P taken on December 4 (see the German Comet Website) it appears that the coma diameter of 12P currently is about 7' (thank you Michael), so to include all of that coma the calculations were made with an 8' aperture diameter. Calculations from 15x20 second green filter images with a 7' aperture diameter from the evening before gave a magnitude of G=8.5.