John Ellard Gore: of immensity and minuteness
  John Ellard Gore FRAS, MRIA (1845-1910) was an Irish amateur astronomer and prolific author of popular astronomy books. His main observational interest was variable stars, of which he discovered several, and he served as the first Director of the BAA Variable Star Section. He was also interested in binary stars, leading him to calculate orbital elements of many such systems. He demonstrated that the companion of Sirius, thought by many to be a dark body, was in fact self luminous. In doing so he provided the first indication of the immense density of what later became known as white dwarfs. 
Jeremy Shears
physics.hist-ph astro-ph.SR