We have updated the afrho measures's database including more than 1200 points for the comet 6P.

References citing CARA

Fulle, M., Barbieri, C:, Cremonese, G:, Rauer, H., Weiler, M., Milani, G., Ligustri, R.
The Dust Environment of Comet 67P/Churyumov-Gerasimenko
In : The New Rosetta Targets. Observations, Simulations and Instrument Performances.
Ed. Luigi Colangeli et al., Astrophysics Space Science Library (2004) – ISBN: 1-4020-2572-6

Fulle, M., Barbieri, C:, Cremonese, G:, Rauer, H., Weiler, M.,Milani, G., Ligustri, R.
The Dust Environment of Comet 67P/Churyumov-Gerasimenko, A&A, 422, 357-368 (2004)

In observing celestial targets most amateur astronomers routinely do not use filters; this helps in getting a better signal to noise ratio, a quite important task when very faint objects are observed and when time exposure is a crucial parameter for instance with fast moving objects or for observing a large number of targets each night.

Measuring comets with the Afρ quantity

Afρ, is a quantity introduced by Michael A'Hearn et al. in 1984 (AJ 89, 579, 1984) with the aim of comparing measurements concerning the dust continuum under different observing conditions, times and instruments.

Before starting in doing photometry with a non professional equipment it is necessary to run a check in order to know if our CCD camera can provide reliable data in this field.

The first requirement is that our equipment response have to be linear, that is, the ADU counts measured in the images must be proportional to the light flux received.