Table 1.

Nebulae whose distances have been estimated from stars involved or from mean luminosities in a cluster

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  • ms = photographic magnitude of brightest stars involved.

  • r = distance in units of 106 parsecs. The first two are Shapley’s values.

  • v = measured velocities in km./sec.    N. G. C. 6822, 221, 224 and 5457 are recent determinations by Humason.

  • mt = Holetschek’s visual magnitude as corrected by Hopmann. The first three objects were not measured by Holetschek, and the values of mt represent estimates by the author based upon such data as are available.

  • Mt = total visual absolute magnitude computed from mt and r.