Minor-planet designation
A formal minor-planet designation is, in its final form, a number–name combination given to a minor planet (
Currently, a number is assigned only after the orbit has been secured by four well-observed
The convention for
Syntax
A formal designation consists of two parts: a catalog number, historically assigned in approximate order of discovery, and either a name, typically assigned by the discoverer, or, the minor planet's provisional designation.[1]
The permanent syntax is:
- for unnamed minor planets:
(number) Provisional designation
- for named minor planets:
(number) Name
; with or without parentheses
For example, the unnamed minor planet (388188) 2006 DP14 has its number always written in parentheses, while for named minor planets such as (274301) Wikipedia, the parentheses may be dropped as in 274301 Wikipedia. Parentheses are now often omitted in prominent databases such as the JPL Small-Body Database.
Since minor-planet designations change over time, different versions may be used in
According to the preference of the astronomer and publishing date of the journal, 274301 Wikipedia may be referred to as 2008 QH24, or simply as (274301). In practice, for any reasonably well-known object the number is mostly a catalogue entry, and the name or provisional designation is generally used in place of the formal designation. So
History
By 1851 there were 15 known asteroids, all but one with their own symbol. The symbols grew increasingly complex as the number of objects grew, and, as they had to be drawn by hand, astronomers found some of them difficult. This difficulty was addressed by Benjamin Apthorp Gould in 1851, who suggested numbering asteroids in their order of discovery, and placing this number in a circle as the symbol for the asteroid, such as ④ for the fourth asteroid, Vesta. This practice was soon coupled with the name itself into an official number–name designation, "④ Vesta", as the number of minor planets increased. By the late 1850s, the circle had been simplified to parentheses, "(4)" and "(4) Vesta", which was easier to typeset. Other punctuation such as "4) Vesta" and "4, Vesta" was also used, but had more or less completely died out by 1949.[6]
The major exception to the convention that the number tracks the order of discovery or determination of orbit is the case of Pluto. Since Pluto was initially classified as a planet, it was not given a number until a 2006 redefinition of "planet" that excluded it. At that point, Pluto was given the formal designation (134340) Pluto.
See also
- index
- Astronomical naming conventions
- Meanings of minor-planet names
- Name conflicts with minor planets
References
- ^ a b "How Minor Planet Are Named". IAU – International Astronomical Union. 2005. Archived from the original on 16 February 2006. Retrieved 5 January 2017.
- ^ a b "How Are Minor Planets Named?". Minor Planet Center. Retrieved 2014-02-25.
- ^ a b "How Many Solar System Bodies". Jet Propulsion Laboratory. Retrieved 18 November 2019.
- ^ "274301 Wikipedia (2008 QH24)". Minor Planet Center. Retrieved 5 January 2017.
- ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 5 January 2017.
- ^ From Dr. James Hilton's When Did the Asteroids Become Minor Planets? Archived 2009-08-25 at the Wayback Machine, particularly the discussion of Gould, B. A. 1852, On the Symbolic Notation of the Asteroids, Astronomical Journal, Vol. 2, and immediately subsequent history. The discussion of C. J. Cunningham (1988), also from there, explains the parenthetical part.