asteroid designation نامگزینی ِ سیارک nâmgozini-ye sayyârak Fr.: désignation des astéroïdes For an asteroid whose orbit is precisely known, a number and optionally
a proper name, e.g. (7) Iris, (24101) Cassini, (99942) Apophis.
For an asteroid whose orbit is not known, a provisional designation composed of
four elements: number.letter.letter.(optionally)number. The first number indicates the year
of discovery. The first letter denotes the half-month of the discovery (A: first half
of January, Y: second half of December; the letter “I” is excluded). The second letter and
the following number indicate the order of discovery within the half-month. For example,
the first asteroid discovered in the first half of May 1960 is: 1960 JA.
Since more than 25 objects (without “I”) might be detected within a half-month,
the number following the second letter indicates the number of 25 discoveries.
Hence, 2001 SD3 was discovered in the second half of September 2001
and was the (D =) 4 + (25 x 3) or the 79th object found during that period.
See also: → asteroid; → designation. |
