[1] In 1890 Frost went abroad to Europe and ended up researching stellar spectroscopy under Hermann Vogel in Potsdam.

[1] Frost joined the staff of Yerkes Observatory in 1898 and became its director in 1905 when George Hale resigned.

[7] Frost's research focused on the determination of radial velocity using stellar spectroscopy and spectroscopic binaries.

[1] He played a significant role in bringing Otto Struve to the United States, when the latter was living as an impoverished refugee in Turkey after the Russian Revolution.

[citation needed] Asteroid 854 Frostia is named in his honor, as is the lunar crater Frost, on the far side of the Moon.