Naming Conventions for Comets

In August of 1995, the General Assembly of the International Astronomical Union adopted a resolution that created a new naming convention for comets.

For the ``old'' comets having relatively short periods, and which have been observed over several different apparitions, a catalog number precedes the common name. For example, the official designation for comet Halley is 1P/Halley.

Newly discovered comets are assigned a name that is based on the year and the half-month in which the comet is discovered. For example, the third comet discovered during the second half of February 1995 would be designated as C/1995 D3. Since comet Hyakutake was the second comet discovered during the second half of January in 1996, its designation is C/1996 B2. Likewise, comet Hale-Bopp becomes C/1995 O1 because it was the first comet discovered during the second half of July in 1995. Notice that the letter ``I'' is not used due to its possible confusion with first Roman Numeral.

The IAU resolution also supported the tradition of naming comets after their discoverers. Thus, the full ``official'' designation for comet Hyakutake, which was discovered by Yuji Hyakutake, is