Science. 1970 Oct 30;170(3957):527-31. doi: 10.1126/science.170.3957.527.
Wide-angle photography of Barnard's Loop Nebula suggests that the nebular emission is much less intense in the 1230- to 2100-angstrom spectral region than in the 2200- to 3200-angstrom near-ultraviolet region. This contrast may be due to differences in the absorption or scattering properties of the interstellar grains in these two wavelength regions.
巴纳德环星云的广角摄影表明，在 1230 埃至 2100 埃光谱区域内，星云发射的强度远低于 2200 埃至 3200 埃近紫外区域。这种对比可能是由于这两个波长区域内星际尘埃的吸收或散射特性的差异造成的。
