Standards for Astronomical Catalogues, Version 2.0 (pdf)
(February 2000)


3.3  Labels


Conventions used for some labels

 
Symbol Explanation Default Limits
RAh Part of the right ascension expressed in hours [0,24[ RAm Part of the right ascension expressed in minutes [0,60[ RAs Part of the right ascension expressed in seconds [0,60[ RAdeg Right ascension expressed in decimal degrees (Alternative: RAhms could be envisaged for a right ascension expressed in sexagesimal with no embedded blanks and leading zeroes, RAbhms for sexagesimal values with embedded blanks. Such extensions would however require special interpretation by FITS readers. ) [0,360[ RArad Right ascension expressed in radians [0,2π[ RAsec Right ascension expressed in seconds [0,86400[ DE- Sign of declination [+-] DEd Part of the declination expressed in degrees [0,90] DEm Part of the declination expressed in arc minutes [0,60[ DEs Part of the declination expressed in arc seconds [0,60[ DEdeg Declination expressed in decimal degrees (Alternative: DEdms could be envisaged for a declination expressed in sexagesimal with no embedded blanks and leading zeroes, DEbdms for sexagesimal values with embedded blanks; questions similar to the RAhms note have to be addressed. ) [–90,+90] DErad Declination expressed in radians [–π/2,+π/2] DEsec Declination expressed in arcsec [–324000,+324000] PosErr Position mean error >=0 dRA  dDE Difference in Right Ascension or Declination oRA  oDE Offset from a reference position in R.A. or Dec. ELON ecliptic longitude [0,360[ ELAT ecliptic latitude [–90,+90] GLON galactic longitude [0,360[ GLAT galactic latitude [–90,+90
Epoch Epoch — write Ep-1900 for a year with 1900 offset plx Parallax pmRA Proper motion in Right Ascension pmDE Proper motion in Declination pmX Proper motion along X direction
Seq a Sequential number used e.g. to number the objects Name the main name of an object or feature
Diam Diameter – or MajDiam and MinDiam >=0 Axis Half Diameter – also MajAxis and MinAxis >=0 PA Position Angle, normally North to East [0,360[ Rad Radius >=0 HRV Heliocentric Radial velocity RVel Radial velocity Sep Separation (anglular or linear) >=0 SpType Spectral type MType Morphological type Vmag Magnitude (apparent) in V filter VMag Absolute Magnitude in V filter Kmag Magnitude (apparent) in K filter ...
Sp+Index Spectral index (α in relation S(ν) = να) Sp-Index Spectral index (α in relation S(ν) = ν–α)
BibCode The 19-digit bibcode Text Free-format text like list of authors, titles...

Remember that a label is always a single word: it cannot contain any embedded blank or space. Other characters are in principle accepted, e.g. parentheses or other punctuation signs, with the following restrictions:

Some commonly used labels are presented in label. This table is not an exhaustive list of all possible column labels; it merely represents the standards adopted for the most common columns headings — like celestial coordinates, times and dates, and some of the most frequently found parameters. The VizieR service contains all definitions of all colums; these definitions are stored in the METAcol (field meta-data) table which can be queried like any of the tables accessible in VizieR. For instance, finding the columns having oscillator strength in their explanation can be found by entering the constraint *oscillator strength* (the * matches any number of characters) in the explain field of the METAcol

Some comments on the labels defined in label:


A parameter has frequently associated values, and we have adopted the rule of association with the one-letter-underscore prefix: if a column is obviously associated to another one — typically m