A Galactic Globular Cluster list (GGCl)

This directory serves as a home for the Galactic Globular Cluster list (GGCl) and a full explanation of its contents; the explanation also has the list of literature references. The list is also available in two parts, essential data -- names, positions, magnitudes, and diameters -- and auxillary data -- names and positions repeated for convenience; color index, total absorption, distance, radial velocity, [Fe/H], age, and references and notes.

Here is a brief explanation of the columns in the tables. Two lines are at the top of the each table with column names first, then a format line with the extent of each field. An "f" in the format line indicates a flag column with an uncertainty flag ":" or "?" when necessary. The full table is 255 columns wide, the essential data table is 160 columns wide, and the auxillary data table is 142 columns wide. All use 7-bit ASCII characters and UNIX line endings, and were constructed on a Mac running OS X 10.11.6.

  • Names, both a "standard" name and popular alternate names, taken from Brian Skiff's 1999 list, or added by me for the "new" clusters.
  • RA and Dec, equatorial position for J2000.0 rounded to 0.1 seconds of time and 1 arcsecond; from my own lists for NGC and IC objects (see the NGC/IC directory), Harris (2010), or the original papers.
  • CC, concentration class from Hogg (1959); Hogg's "I" = 1, "II" = 2, and so on to "XII" = 12.
  • VT, adjusted total V magnitude, or weighted mean total V magnitude,
  • σ1, standard deviation of VT (see text).
  • Ve, effective (half-light) magnitude, VT + 0.75.
  • De, effective (half-light) diameter, arcminutes.
  • μe, mean visual surface brightness within De; V-mag arcmin-2. Add 8.89 for V-mag arcsec-2.
  • b/a, axial ratio from White and Shawl (1987) or Harris (2010); may be taken as "1.0:" if no entry.
  • D25, cluster diameter at the 25.0 V-mag arcsec -2 isophote, in arcminutes.
  • V25, integrated cluster magnitude within the D25 isophote.
  • D24, cluster diameter at the 24.0 V-mag arcsec -2 isophote, in arcminutes.
  • V24, integrated cluster magnitude within the D24 isophote.
  • D23, cluster diameter at the 23.0 V-mag arcsec -2 isophote, in arcminutes.
  • V23, integrated cluster magnitude within the D23 isophote.
  • D22, cluster diameter at the 22.0 V-mag arcsec -2 isophote, in arcminutes.
  • V22, integrated cluster magnitude within the D22 isophote.
  • μC, central surface brightness, V-mag arcsec -2. Subtract 8.89 for V-mag arcmin-2.
  • Vtip, magnitude for the tip of the red giant branch from Skiff (1999) or more recent color-magnitude diagrams (references are in the Notes column).
  • Vhb, magnitude for the horizontal branch, from Skiff (1999), Harris (2010), or more recent color-magnitude diagrams (references are in the Notes column).
  • B-V, color index from Harris (2010), or unpublished observations (see text).
  • AV = 3.1 EB-V, total V-band absorption; EB-V from Harris (2010) or from NED's extinction calculator.
  • Dist, heliocentric distance in Kpc from Francis and Anderson (2014), Harris (2010), or Baumgardt et al (2019).
  • RVh, heliocentric radial velocity from Harris (2010) or more recent sources (references are in the Notes column).
  • [Fe/H], cluster metallicity from Harris (2010) or more recent sources (references are in the Notes column).
  • Age, approximate cluster age in Gyr from Baumgardt (2020b), for best-fitting color-magnitude isochrone.
  • Notes and References, recent papers with additional data, or relevant notes.
  • Creative Commons License
    Galactic Globular Cluster list by Harold G. Corwin, Jr. is licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported License.

    This means that you are welcomed to use the information in any way you like, (and can fix any mistakes you find!), but please do acknowledge its origin.

    Latest update, this file: 19 March 2021.