Utrecht Atlas
| Author | Marcel Minnaert; Gerard Mulders; Jakob Houtgast |
|---|---|
| Original title | Photometric Atlas of the Solar Spectrum from λ3612 to λ8771 with an Appendix from λ3332 to λ3637 |
| Subject | Solar observation; Solar physics |
| Publisher | Sterrewacht "Sonnenborgh" |
Publication date | 1940 |
| Publication place | Netherlands |
| Pages | 174 pages of microphotometer tracings with an introduction in English and Esperanto |
The Utrecht Atlas of the solar spectrum is a detailed inventory in graphical form of spectral lines observed in sunlight at the Sonnenborgh Observatory. The visible spectrum is about 390 to 700 nm and the atlas covers from 361.2 to 877.1 nm (plus an appendix) so that the atlas has some coverage of the infrared and ultraviolet spectrum of sunlight. The atlas, compiled by Minnaert and his students Mulders and Houtgast, was published in 1940 shortly before the WWII invasion of the Netherlands.
The Atlas contains intensity curves covering the complete solar spectrum from λ 3612 to λ 8771 based on photographs taken at the Mount Wilson Observatory together with an appendix covering the region λ 3332 to λ 3637 as derived from plates secured at Utrecht. The scale in wave length is about 20 millimeters per angstrom so that the spectrum is represented on a map about 360 feet long. The curves are printed in black on millimeter paper with blue lines. The intensity scale is such that a vertical range of 100 millimeters corresponds to the difference between zero intensity and the continuous background.
The atlas had a huge influence on solar and stellar high resolution spectroscopy after World War II.