نامگزینی ِ دنبالهدار
Fr.: désignation des comètes
A → nomenclature system for naming
In early 1995, a new comet designation system was established by the
→ International Astronomical Union. The main rules
are as follows:
a) If the comet is a newly discovered one, it first gets a provisional name,
which closely matches the → asteroid designation
system. For example, the first comet discovered in
the first half of 1998 January is designated 1998 A1, the second 1998 A2,
b) The name of the person(s) who discovered the comet may
be added to this designation (limited, however, to three names). For example, comet
→ Hale-Bopp (C/1995 O1) has its full name as Hale-Bopp C/1995 O1,
whereas its designation is C/1998 O1. If several people are involved with a
discovery at an observatory, the comet may be named after the observatory instead of the
c) → Long-period comets and one-apparition
→ periodic comets receive
only a provisional designation.
d) A → short-period comet would get the
P/designation until it is recovered in a second → apparition.
At this point, the
P/Year designation would be replaced with a number followed immediately by an upper case P,
and a slash followed by the name of the discoverer(s). The number here is
one more than the number of known periodic comets that have reappeared. For example,
Hug-Bell (P/1999 X1) was given the full name 178P/Hug-Bell after it reappeared in
2007. Previously, 177 periodic comets had got assigned numbers.
e) Long-period comets are indicated by the prefix C.
f) If the comet is destroyed, or if it fails to appear after several
apparitions, it would be prefixed D/
(→ defunct comet) followed by the year of
its discovery. For example, → Comet Shoemaker-Levy 9
has been assigned D/1993 F2 since it was discovered in the second half of March in 1993
and was destroyed when it crashed into Jupiter in 1994.
g) Comets that lack sufficient position
measurements for an orbital determination are given the designation of X/ followed
by the year of their discovery and the appropriate letter and number code.
h) When a → comet nucleus
nucleus splits, each fragment
is given the comet designation followed by A, B, C, etc (for fragments).
→ comet; → designation.