Complex sentence: The designation "HD 40307" is from the Henry Draper Catalogue, which is based on spectral classifications made between 1911 and 1915 by Annie Jump Cannon and her co-workers, and was published between 1918 and 1924.
Split into simpler sentences: The designation "HD 40307" is from the Henry Draper Catalogue. This catalogue was based on spectral classifications made between 1911 and 1915 by Annie Jump Cannon and her co-workers, and was published between 1918 and 1924.