Published online by Cambridge University Press: 14 August 2015
Photometric measurements of the emission nebulosities in the LMC are not numerous. Doherty, Henize, and Aller (1956) microphotometered both widened and unwidened objective-prism photographs covering a narrow wavelength range near Hα to obtain cross-sectional “intensity profiles” for certain nebulosities in the Large Cloud. These intensities were converted to surface brightnesses by tracing the widened spectra of stars of known magnitude and colour and using the method of Ambartsumian (1933). Peak intensities for each scan across a nebulosity are given in erg cm–2 sec–1 steradian–1.