Friedrich Tietjen

{| class="wikitable" align="right" style="margin-top: 0; margin-left: 1em; font-size: 0.9em;" |+ Asteroids discovered: 1  | 86 Semele || 4 January 1866 || |}

Friedrich Tietjen (1832 in Westerstede, Oldenburg – 1895 in Berlin) was a German astronomer.

He was director of the ''Astronomisches Rechen-Institut'' (ARI) from 1874 until his death in 1895. The Minor Planet Center credits him with the discovery of one minor planet, the 120-kilometer sized asteroid 86 Semele.

The main-belt asteroid 2158 Tietjen, discovered by Karl Reinmuth at Heidelberg Observatory in 1933, was named in his memory. Provided by Wikipedia