Gruss was born on August 3, 1854 in Jitschin (Bohemia). While studying at Prag University he was an assistant at the Observatory (directed by Karl Hornstein). After his PhD in 1877 he went to Vienna and returned to Prag in 1881. In 1892 he became Professor of Astronomy at Prag University and directed the Observatory (at Smichov) until 1914. He was interested in variable stars and visual stellar spectroscopy. Gruss visually found IC 4997, a planetary nebula in Sagitta, around 1896 with the aid of a spectroscope. The object was found parallel by Williamina Fleming at Harvard with an objective prism, probably a bit earlier. Gruss used the 6" Steinheil refractor (erected in 1870) or the 8" aequatorial by Reinfelder & Hertel. He died on Sept. 13, 1922 in Prag. The minor planet (6516) Gruss bears his name.
|I||4997||1896?||6,0?||Rr||vs||Fleming 1896||SGE||PN||3||Weinek, L.||Astronomische Beobachtungen an der K. K. Sternwarte zu Prag 1892-99|
Obituary: AN 217, 127 (1923)