12P remains fainter since its last eruption around April 3. 12P on the evening of 2024 April 14 UT was magnitude G=4.6 as calculated from several different stacks of 12x15 second images taken thru a green filter in an aperture diameter of 10'. The several different stacks of 12x15 second images each taken thru a green filter were a test to see what difference there would be in magnitude calculations from a bright sky at 0248UT altitude 9.5 degrees, a fairly dark sky at 0256UT altitude 7.8 degrees and a sky close to the horizon with lots of light pollution at 0311UT altitude 4.8 degrees. All of the software settings used in the calculations were the same for each of the image stacks. The surprise was that for each of the image stacks the calculated magnitude was the same at G=4.6. As noted by others with the comet a little fainter than a week ago and the light from the comet having to go thru more atmosphere it is getting harder to see much of the tails, if indeed there is much to be seen anymore from Earth. |
Page last updated: Mon 16 Sep 11:44:14 BST 2024