Alkmene was discovered by R. Luther on 7 November 1864 and named after Alcmene, the mother of Herakles in Greek mythology.

Based on IRAS data, Alkmene is estimated to be about 61 kilometres (38 mi) in diameter.

[3] A satellite has been suggested based on 1985 lightcurve data.

[4] Asteroid Alkmene occulted the apparent magnitude 7.5 star HIP 99229 in the constellation of Capricornus on 18 September 2014 around 06:41 UT (17 September 23:41 PDT) and was centered on Sacramento, CA.

[5][6] Alkmene projected an eclipse shadow that moves at about 3.2 km/s (2 mi/s).