Julius Scheiner – 19th century extragalactic spectroscopy

Juluis Scheiner published a lot in German language and made a lot of solar and stellar research. I’m concentrating on his English production on extragalactic issues. Scheiner (1898) studied the reason why nebular spectra sometimes showed Hβ lines while showing little or no Hα lines, which seemed to go against the common knowledge back then [...]

George Paddock – early work on cosmological redshift

In addition to the work on extragalactic objects, George Paddock did some work on planets, stars, and galactic nebulae. He also worked on the radial velocity equations of binary stars. Here, I will concentrate on his extragalactic work (which contains only couple of papers). Paddock (1916) discussed spiral galaxies in their relation to the galactic [...]

Knut Lundmark – extragalactic distance scale

Lundmark & Lindblad (1917) studied the spectral types of spiral galaxies. For NGC 3031 (Messier 81) they noted that Edward Fath had earlier determined that the spectrum resembles that of a K star, and their analysis also showed that if the spectral types of stars were applied to NGC 3031 spectrum, it would belong to [...]

Edward Fath – early spectroscopy of galaxies

Although I’m concentrating on Fath’s extragalactic work, I’ll mention a paper among his early works as a curiosity; Steppins & Fath (1906), titled “The Use of Astronomical Telescopes in Determining the Speeds of Migrating Birds”. Fath (1909) measured spectra of spiral galaxies, but he wasn’t able to determine their redshifts. He noted that by that [...]

Francis Pease – Dark matters

Francis Pease is known for his work on measuring star diameters, but here I will have a look at his work on spectroscopy of extragalactic objects. Francis Pease’s first extragalactic works were simply publishing measured radial velocities of galaxies and communicating some details on their spectra (Pease, 1915a, 1915b, 1915c, 1916a). Pease (1916b) was closing [...]

Vesto Slipher – the redshift anomaly pioneer

Vesto Slipher was the first to measure the redshift of an extragalactic object. Slipher (1913) noted that the spectroscopic faintness of extragalactic objects were the main reason for the lack of redshift measurements by that time. The object he chose as the target was the “Andromeda nebula” (today known as “Andromeda galaxy”), M31. He gave [...]