Article 4 pages Level: high school and above This is an 1868 paper by Fr. Angelo Secchi, who conducted pioneering research into the nature of stars and whose work laid the foundations for the modern Vatican Observatory.  Here Fr. Secchi groups stars by the characteristics of their spectra, noting that stars seem to fall into a certain number of types.  He writes, “We have therefore, without doubt, in the heavens a grand fact, the fundamental distinction between the stars according to a small number of types; this opens a field for very many important cosmological speculations.”  He also notes that observing the spectra of stars can tell us something about their motions.  Indeed, studying the motions of stars by means of their spectra has yielded all sorts of information about them, including whether they have planets orbiting them. Fr. Secchi’s paper was published in the Report of the Thirty-Eighth Meeting of the British Association for the Advancement of Science [1868]. Click … Continue reading →