Dictionary of Nomenclature of Celestial Objects

nearest arcminute, except for sources less than 0.5' from the center, which are also assigned a first digit of "1"). The second character (1-4) represents the quadrant in which the source falls (counterclockwise from the northwest quadrant "1"). The last character is a letter (a-l), in the order of azimuthal position (working counterclockwise) within a given annulus and quadrant.
in source:ome Cen = NGC 5139
Ref:=2009ApJ...697..224H
byHAGGARD D. , COOL A.M., DAVIES M.B.
 Astrophys. J., 697, 224-236 (2009)
  A Chandra study of the Galactic globular cluster ω Centauri.
oTable 1, col(1): <[HCD2009] NNNa> N=180 = Table 1, col(2): <CXOHCD JHHMMSS.ss+DDMMSS.s> N=180.
Ref:=2018MNRAS.479.2834H
byHENLEYWILLIS S. , COOL A.M., HAGGARD D., HEINKE C., CALLANAN P., ZHAO Y.
 Mon. Not. R. Astron. Soc., 479, 2834-2852 (2018)
  A Deep X-ray Survey of the globular cluster Omega Centauri.
oTable 1: <[HCD2009] NNNa> N=95 among (Nos 11d-113b) added.
=E=Catalogue in electronic form as J/ApJ/697/224
=E=Catalogue in electronic form as <J/MNRAS/479/2834/>

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