What Else Did V. M. Slipher Do?

TL;DR

V. M. Slipher's diverse spectroscopic work significantly advanced planetary, stellar, and interstellar astronomy, with key discoveries on planetary rotation, interstellar dust, and the search for Planet X, despite limited later scientific activity.

Contribution

This paper highlights the breadth of V. M. Slipher's contributions to astronomy beyond galaxies, emphasizing his discoveries and leadership at Lowell Observatory.

Findings

First spectroscopic measurement of Uranus's rotation

Evidence of interstellar dust through reflection nebulae

Confirmation of interstellar calcium and sodium lines

Abstract

When V. M. Slipher gave the 1933 George Darwin lecture to the Royal Astronomical Society, it was natural that he spoke on spectrographic studies of planets. Less than one-sixth of his published work deals with globular clusters and the objects we now call galaxies. In his most productive years, when he had Percival Lowell to give him direction, Slipher made major discoveries regarding stars, galactic nebulae, and solar system objects. These included the first spectroscopic measurement of the rotation period of Uranus, evidence that Venus's rotation is very slow, the existence of reflection nebulae and hence interstellar dust, and the stationary lines that prove the existence of interstellar calcium and sodium. After Lowell's death in 1916 Slipher continued making spectroscopic observations of planets, comets, and the aurora and night sky. He directed the Lowell Observatory from 1916 to 1954, where his greatest achievements were keeping the observatory running despite very limited staff and budget, and initiating and supervising the "successful" search for Lowell's Planet X. However, he did little science in his last decades, spending most of his time and energy on business endeavors.