Representation of the A. L. Cochran et al. (2012) catalog, limited to LPC comets. The blue bars represent the highest heliocentric distance at which any comet was observed, and the orange bars are the highest heliocentric distance at which the comet displays the CN band. Three comets were observed beyond 4 au, and two of them also have CN at this distance: comet Hale–Bopp and comet Shoemaker.