A paper by William Herschel, presented at The Royal Society on 3rd February, 1785.
"That the milky way is a most extensive stratum of stars, of
various sizes, admits no longer of the least doubt; and that our
sun is actually one of the heavenly bodies belonging to it is as
evident. I have now viewed and gauged this shining zone in
almost every direction, and find it composed' of stars."
—William Herschel
William Herschel's paper describing his investigations of the nigh sky, is to this day an excellent read, and fascinating to me as much for its its historical perspective value as its astronomical, scientific value. Until Herschel had built the telescope he used to make his observations, the Milky Way was still a mystery to astronomers, being seen as simply a pale cloud in the sky. Herschel was delighted and surprised to discover that what appeared as a fuzzy belt of light was in fact composed of many, many stars.
Herschel continued to make systematic observations of the sky, noting the numbers of stars and their brightness in each field. As a good scientist, he kept detailed and copious notes, and at the end was able to conclude that the Milky Way was in fact a disc-shaped object, and also that the Sun was surrounded by, and a part of, this disk. throughout his observations he notes many "nebulae", which we now know to be even more galaxies.
Herschel also provides tables of his observations, his star count, and the details of his telescope that would enable others to verify his conclusions. he had also identified many binary stars, but was disappointed that he could not use them to verify their distance by parallax.
Following this project, he went on to search for other nebulae and in the process, managed to discover the planet Uranus.
link to his paper.
$ xclip -o | wc -w
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