Commission B2 Working Group on Designations
Helpful Hints:
Description of the Formats
This document details the symbols used in formatting the sequence of astronomical designations, and provide examples of use (and misuse).
Contents:
1 Inventory of the formats
| Symbols | Meaning |
|---|---|
| - | dash or hyphen |
| + | sign (+ or -) |
| +BB.b | Degrees of galactic latitude (as many decimals as lowercase b 's) |
| +DDd | Degrees of declination (as many decimals as lowercase d 's) |
| AA | Uppercase-only text (as many letters as A 's) |
| aa | alphabetic text (as many letters as a 's) |
| CCC | iConstellation 3-letter abbreviation (Official list) |
| B | Introduces the coordinates based on B1950 Equinox |
| D | Tens of degrees of declination |
| DD | May be degrees of declination (in principle preceded by a sign), or Day-in-month numeral |
| DD.dd | Day-in-month and fractions of day (as many decimals as lowercase d 's) |
| DDD.d | Right ascension expressed in decimal degrees (as many decimals as lowercase d 's) |
| FF | Field number (as many digits as F 's) |
| G | introduces the Galactic coordinates (optional) |
| HH.hh | Hours of right ascension (as many decimals as lowercase h 's) |
| J | Introduces the coordinates based on J2000 Equinox (and ICRS) |
| LLL.l | Degrees of galactic longitude (as many decimals as lowercase l 's) |
| M | May be units of minute (range 0 to 9) if followed by SS , m or a decimal point; represents tens of minutes (range 0 to 5) otherwise |
| MM | May be minutes (of hour or degree), or month numeral |
| MMm | Minutes of right ascension or declination, (as many decimals as lowercase m 's) |
| NNN | Ordinal number (as many digits as N 's) |
| NN.N | Ordinal number with inserted numbers (as many digits as N 's) |
| RRR | Roman numeral (as many R 's as maximal length) |
| S | May be units of seconds (range 0 to 9) if followed by s or a decimal point; represents tens of seconds (range 0 to 5) otherwise |
| SS.s | Seconds of right ascension or declination, (as many decimals as lowercase s 's) |
| VVV | Velocity in km/s (as many digits as V 's) |
| VVV.v | Velocity in km/s with decimals |
| Z | Redshift (as many digits as Z 's) |
| Z.z | Redshift with decimals |
| vvv | Volume number |
| W | A letter indicating one of the 4 directions (N, S, E or W) |
| WW | Letters indicating one of the 4 directions (NE, NW, SE, SW) |
| xxxx.x | Offset along x-axis from some reference position in any kind of unit (pixel, arcsec, mm, etc) |
| YYYY | Year (YY when 2 digits, YYYY when 4 digits) |
| yyyy.y | Offset along y-axis from some reference position in any kind of unit (pixel, arcsec, mm, etc) |
| {NGC|IC} | One of the alternatives listed between the curly braces
{
... }
and separated by the vertical bars
|
— here either the text
NGC or the text
IC
. An empty text is possible as e.g.
{Q|G|}
means either the letter
Q , the letter
G
, or nothing. Note: it is possible to use 2 dots .. to indicate a range of letter, e.g. {A..E} is equivalent to {A|B|C|D|E} . To specify a upper- or lower-case letter in the range A to E, one can write {A..E|a..e} (modified in November 2006) |
2 Typical formats (usual or recommended)
| Format | Example | Remarks |
|---|---|---|
| Running number | ||
| NNN... | HD | |
| Declination zone | ||
| +DD NNN | BD-28 2411 | |
| Sk-69 72 | Not Sk72-69 | |
| Equatorial coordinates | ||
| HHMM+DD | PKS | |
| HHMM+DDd | PKS | |
| BHHMM+DD | PSR | |
| BHHMM+DDd | PKS | |
| JHHMM+DDMM | PSR | |
| PKS | ||
| HHMMm+DDMM | IRAS | Point Source Cat. |
| HHMM.m+DDMM | 1E | (IPC) |
| HHMMSS+DDMMSS | 6C | |
| HHMMSS.s+DDMMSS | 1E | (HRI) |
| BHHMMSS.s+DDMMSS | 6C | |
| JHHMMSS.ss+DDMMSS.s | SDSS | |
| Galactic coordinates | ||
| LLL.ℓ+BB.b+VVV | HVC | |
| GLLL.ℓ+BB.b | PN | |
| Field | ||
| FFF-NNNN | LP | hyphens are recommended |
| ESO | ||
| FFFF-NNNNN | GSC | |
| Constellation | ||
| CCC YYYY | Nova | |
| Year or Date | ||
| YYYYA | SN 1987A | |
| YYYYaa | SN 1993aj | |
| YYMMDDA | GRB 991216 | γ-ray burst |
| YYYY MMM DDA | GB 1979 Nov 05A | |
3 Misleading formats (obsolete or confusing)
| Format | Remarks |
|---|---|
| NN+DD | Sk 72-69 instead of Sk-69 72 |
| HHNDA | Pawsey (1955P1), First use of the coordinates in the format |
| +DD.NN | as in OB to OZ (1967S1) |
| +DNN.N | any combination where the point does not mean a decimal point or the declination is in tens of degrees |
| HH.MM.m.NN | GN by Neckel (1985NV), any combination where the point does not mean a decimal point |
| HHMM+DD.N | where the point does not mean a decimal point (e.g. Glazar) |
| HHMM+DDM | truncating to tens of arc minutes in declination is strongly discouraged, use +DDd or +DD.d instead. |
| HHMM+DDdd | Don't use hundredths of degrees, but the sexagesimal division +DDMM |
| MMSS+MMSS | Do not omit the leading HH and DD |