Comet Afrho and Water Production Rate

“The [Afrho] parameter and the cometary activity. The [Afrho] parameter is a parameter defined by A’Hearn et al. (1984) to measure the activity of comets. This parameter is proportional to the dust “filling factor”, the ratio of the integrated cross section of the dust particles and the projected surface of the diaphragm in the field of view. The use of this parameter will be discussed. Simple ways of calculating it from calibrated CCD images of comets will be explained and illustrated with examples. The total magnitude depends on the diaphragm used and the wavelength and is a mix of dust and gas emissions. Afrho allows the monitoring of the dust emission rate of comets, dust properties through reddening and the gas to dust ratio.

We estimated the comet Afrho and water production rate for comet C/2022 E3.

CometC/2022 E3
CCD bin2
CCD pixel micron3.76
CCD resolution arcsec/pixel0.67
Tycho Aperture30
Photometric aperture20.1
comet to earth distance AU0.5
comet to sun distance AU1.229
Sun R Mag-27.09
Comet R band mag8.52
Comet phase angle 50.3
Afrho (cms)5917
mH Heliocentric mag9.02
Water Production rate Q(H2O) Kg/sec867.09
Telescope dia mm 330
Focal mm2320
Observer Gowri Visweswaran
Measures V. K. Agnihotri