Description of the Formats

This document details the symbols used in formatting the *sequence* of
astronomical designations, and provide examples of use (and misuse).

Symbols | Meaning |
---|---|

- |
dash or hyphen |

+ |
sign (+ or -) |

+BB.b |
Degrees of galactic latitude (as many decimals as lowercase 's) b |

+DDd |
Degrees of declination (as many decimals as lowercase 's) d |

AA |
Uppercase-only text (as many letters as 's) A |

aa |
alphabetic text (as many letters as 's) a |

CCC | Constellation 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 's) d |

DDD.d |
Right ascension expressed in decimal degrees (as many decimals as lowercase 's) d |

FF |
Field number (as many digits as 's) F |

G |
introduces the Galactic coordinates (optional) |

HH.hh |
Hours of right ascension (as many decimals as lowercase 's) h |

J |
Introduces the coordinates based on J2000 Equinox (and ICRS) |

LLL.l |
Degrees of galactic longitude (as many decimals as lowercase 's) l |

M |
May be units of minute (range 0 to 9) if followed by , SS or a decimal point; represents tens of minutes (range 0 to 5) otherwise m |

MM | May be minutes (of hour or degree), or month numeral |

MMm |
Minutes of right ascension or declination, (as many decimals as lowercase 's) m |

NNN |
Ordinal number (as many digits as 's) N |

NN.N |
Ordinal number with inserted numbers (as many digits as 's) N |

RRR |
Roman numeral (as many 's as maximal length) R |

S |
May be units of seconds (range 0 to 9) if followed by or a decimal point; represents tens of seconds (range 0 to 5) otherwise s |

SS.s |
Seconds of right ascension or declination, (as many decimals as lowercase 's) s |

VVV |
Velocity in km/s (as many digits as 's) V |

VVV.v |
Velocity in km/s with decimals |

Z |
Redshift (as many digits as 's) Z |

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
| or the text
NGC. An empty text is possible as e.g. IC
means either the letter
{Q|G|}
, the letter
Q
, or nothing. G
: it is possible
to use 2 dots Note to indicate a ..
range of letter,
e.g. is equivalent to {A..E}
. To specify a upper- or lower-case letter in
the range A to E, one can write
{A|B|C|D|E}
{A..E|a..e} (modified in November 2006) |

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 |

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 |