Born Nikolaev, (Ukraine), 26 November/8 December 1831
Died Saint Petersburg, Russia, 1/14 May 1904
Comets, and especially the nature of their tails, were Fyodor Bredikhin’s major preoccupation throughout his entire scientific career.
After graduation in 1855 from Moscow University, Bredikhin conducted his postgraduate study there, also working at the Moscow Observatory. In 1862 he defended his master’s thesis, On the Tails of Comets, and in 1864 his doctoral dissertation, Perturbations of Comets that do not Depend on the Gravitational Attraction of Planets. The same year Bredikhin was appointed professor at Moscow University and in 1873 became director of the university’s observatory. He then succeeded Otto Wilhelm Struve , the first director of the Pulkovo Observatory, in 1890. Bredikhin retired from his observatory post in 1895, for health reasons.
Bredikhin held memberships in the Russian Astronomical Society, Deutsche Akademie der Naturforscher Leopoldina in Halle (1883), the Royal Astronomical Society (1884), the Italian Society of Spectroscopists (1889), and the Bureau des longitudes in Paris (1894). In 1892, the University of Padua awarded him an honorary doctorate.
Beginning with his first paper on the subject, “Quelques mots sur les queues des comètes” (1861), Bredikhin carried out extensive observational and theoretical studies of comets. His work on the subject continued after his retirement and culminated in the so called mechanical theory aimed at explaining the peculiar shape of cometary tails. They are typically directed toward the Sun near the nucleus but then curve away from it, forming multiple jets, as if they were repelled by the Sun. Bredikhin classified cometary tails into three types depending on the magnitude of this effective repulsive force. Although his theory was later abandoned, some aspects of his classification are still valid.
Bredikhin’s other projects ranged from gravimetry to astrophysical spectroscopy to observations of meteor showers and the zodiacal light. His studies of the solar corona resulted in a theory that noted a connection between coronal streamers and chromospheric filaments and the lack of a direct connection between such streamers and sunspots.