All Tables

Table 1: Observational data. r is the heliocentric distance. $m_{\rm r}$ is the heliocentric visual magnitude. 2dc is the McDonald 2D-coude spectrograph, SOFIN and UVES are the high-resolution spectrographs at, respectively, the NOT and ESO VLT telescopes. n is the number of spectra obtained, for a total exposure time of Exp. Extent is the size of the zone explored at the distance of the comet. R is the instrumental resolving power. Fwhm is the measured width of the CN lines.
Table 2: The carbon and nitrogen isotopic ratios, and the corresponding estimated errors in parentheses.