Hi, I'm looking for a copy of Mardsen's Catalogue of Cometary Orbits. An outdated version would be okay. Can't seem to find one at any local Utah library. I'm looking for a table that would include both the perihelion distance in a.u. and the maximum observed diameter for the comet's coma. This is related to Comet 17P Holmes. I understand that there is a relationship between the perihelion of a comet and diameter of the coma. As a comet gets closer to the Sun, the pressure of solar wind causes the coma size to shrink. Short period comets that do not get close to the Sun at perihelion can have larger comas because there is less pressure from the solar wind pushing against the dust ejecta from the nucleus. Apparently, the Mardsen's catalogue put out annually by the Harvard Center for Astrophysics may have the right table but they restrict distribution to paper to keep up their royalty revenue stream. Anyone have an copy of this that they could lend me? - Thanks, Kurt _______________________________________________ Sent via CSolutions - http://www.csolutions.net