Astrometrical and photometrical survey of comets
beyong 3 UA

Francois COLAS, Patrick ROCHER  Bureau des Longitudes
Laurent JORDA, Observatoire de Meudon

    We are planning to observe comets at a 3 UA of the sun, as there is quite
no cometary activity at this heliocentric distance, it is possible to make
good astrometrical observations. We want to compute good orbital elements
before and after perihelion, these data are very important to compute
non gravitational effects. As there is no coma it is also possible to
measure the rotational period and the shape of the nucleus. We plan to
observe during 5 years to obtain most of the periodic comets.