2134 Dennispalm (1976 YB) is a main-belt asteroid discovered on December 24, 1976 by Charles T. Kowal at Palomar Observatory. It is named in honor of C. Dennis Palm, who worked as a night assistant at Caltech's 48" Schmidt telescope on Palomar Mountain in the 1960s and later at Caltech's 60" reflecting telescope, also on Palomar. Palm died on December 26th, 1974.
Photometric observations made in 2003 at the Carbuncle Hill Observatory near Providence, Rhode Island give a synodic rotation period of 4.114 ± 0.002 hours. The light curve shows a brightness variation of 0.37 ± 0.05 in magnitude.