ADES and comet observations

aje160744 Dec 9, 2018

Bill and others,

Does anyone know of any standards or guidelines being set on the use of ADES for comet observations reporting?

The issue is that comets used to be reported with Nucleus ( N ) or Total ( T ) magnitudes. Even though the selection of aperture was subjective, the intention to capture all, or just the centre, of the comet was obvious. With ADES the aperture used for photometry is specified in the report but there is no indication of how much of the comet was intended to be measured. This is also linked with the problem that observations made with a large aperture (to capture all/most of a comet) usually provide poor astrometry while an aperture small enough to get good astrometry often provide meaningless photometry.

Tony Evans