Reply To: Using ASTAP for comet measurements

[Nick James]

Mark,

Your 5.6 is a little brighter than comphot’s estimate which was 5.8 but that is not a bad agreement for a big comet. The full output from comphot is:

10×10 20×20 30×30 40×40 50×50 60×60
10.07 9.00 8.41 8.06 7.79 7.58 # Counts
10.07 9.02 8.48 8.11 7.84 7.62 # Median annuli
Total integrated magnitude: 5.78 (radius 891.1 arcsec)
COMPHOT: 1.4.6 2023 01 23.052 5.78 29.70 18.47 23.50 19.02 3076.2 5.50 Astrometrica 4.12.0.448 Nick James C_2022_E3__ZTF_ G_2022_E3_o_0000.fit

These measures are pretty much in the middle of the estimates on COBS:

https://cobs.si/analysis/?comet=2323&from_date=2022-06-01+00%3A00&to_date=2023-04-01+00%3A00&observation_type=V&observation_type=C&plot_x_value=1&plot_y_value=1&fit_option=1&observer=&association=&country=&compare_values=filter

Could you provide a step-by-step description of the approach that you used with ASTAP please?