Документ взят из кэша поисковой машины. Адрес оригинального документа : http://www.ipa.nw.ru/PAGE/FUNDAMENTAL/LSBSS/engthelp.htm
Дата изменения: Unknown
Дата индексирования: Sun Apr 10 01:15:58 2016
Кодировка:

Поисковые слова: comet tail
Head Litter of Minor Planet Names

Readme

     Present section contains two Tables: the first one lists the names of all minor planets in alphabetic order as of the last updating of the Table.
     The second Table lists the numbered minor planets in order of their numbers. For each minor planet the Table, apart from number represents also the name of minor planet, if any, and its principal preliminary designation.
     The first Table is subdivided into the parts according to the first letter of name. When spelling some names the diacritics are used. They are displayed with the help of special symbol codes of HTML. As sometimes such symbols can not be read by some browser, provision is made to see correct spelling of names in TeX format (on clicking such names).
     The second Table is subdivided into the parts each containing one thousand minor planets. Here also the same possibility is foreseen to see spelling in TeX format as in the first Table.
     Bellow the rules for assigning preliminary designations to minor planets are shortly described.
     The Minor Planet Center (Cambridge, USA) assigns preliminary designation to an object having the observations at least in two nights that can not be immediately identified with some already numbered or designated object. Such designations consist of a year followed by two letters and optional one, two, or three digits. The first letter corresponds to the half-month period within indicated year, when the object was firstly observed (discovered). The following Table lists the letters one-to-one with half-month periods:

A Jan.    1–15
B Jan.  16–31
C Feb.   1–15
D Feb. 16–29
E Mar.   1–15
F Mar. 16–31
G Apr.   1–15
H Apr. 16–30
J May   1–15
K May 16–31
L June   1–15
M June 16–30
N July    1–15
O July  16–31
P Aug.  1–15
Q Aug. 16–31
R Sep.   1–15
S Sep. 16–30
T Oct.   1–15
U Oct. 16–31
V Nov.   1–15
W Nov. 16–30
X Dec.   1–15
Y Dec. 16–31

     I is omitted and Z is unused. The second letter in designation corresponds to the order of the designation within half-month (letters from A to Z with I omitted). In case there are more than 25 designations within half-month the second letter is recycled and numeral '1' is added to the designation (e.g. 1995 SA1, 1995 SB1, ..., 1995 SA2, ...). If more than 250 discoveries take place within one half-month, the second letter is followed by two digits (e.g. 1995 SA10, 1995 SB10, etc). It can happen that last letter is followed by three digits. For example, 2000 WR106 is the designation of an object discovered on 28 November, 2000 and it is 2667th object in the second half-month of November.
     Apart these preliminary designations special ones are used for minor planets discovered in the course of special surveys, undertaken between 1960 and 1977. Such designations consist of a number (identifying the order within that survey), a space and a survey identifier. The survey identifiers are as follows:

SurveyIdentifier
Palomar-Leiden (1960) P-L
First Trojan Survey (1971) T-1
Second Trojan Survey (1973) T-2
Third Trojan Survey (1977) T-3

     Examples of designations are 2040 P-L, 3138 T-1, 1010 T-2 and 4101 T-3.
     It is important to stress that preliminary designation gives an idea of date of minor planet discovery.