From the passage provided, extract the years when the galaxies were added to the catalogue. Include the names of astronomers that added them. Separate them with a comma.

The catalogue consists of a diverse range of astronomical objects, from star clusters and nebulae to galaxies. For example, Messier 1 is a supernova remnant, known as the Crab Nebula, and the great spiral Andromeda Galaxy is M31. Further inclusions followed, the first addition came from Nicolas Camille Flammarion in 1921, who added Messier 104 after finding Messier's side note in his 1781 edition exemplar of the catalogue. M105 to M107 were added by Helen Sawyer Hogg in 1947, M108 and M109 by Owen Gingerich in 1960, and M110 by Kenneth Glyn Jones in 1967.

1921, Nicolas Camille Flammarion
1947, Helen Sawyer Hogg
1960, Owen Gingerich
1967, Kenneth Glyn Jones