Melpomene occulted the star SAO 114159 on 11 December 1978. A possible Melpomenean satellite with a diameter at least 37 km was detected. The satellite candidate received a provisional designationS/1978 (18) 1.[14] In 1988 a search for satellites or dust orbiting this asteroid was performed using the UH88 telescope at the Mauna Kea Observatories, but the effort came up empty.[15] Melpomene was observed with the Hubble Space Telescope in 1993. It was able to resolve the asteroid's slightly elongated shape, but no satellites were detected.[5]
Melpomene has been studied by radar.[16]Photometric observations during 2012 provided a rotation period of 11.571±0.001 h with a brightness variation of 0.34±0.02 in magnitude, which is consistent with previous studies.[17] It has a mean diameter of 141±2 km.[7][3]
^Gradie, J.; Flynn, L. (March 1988), "A Search for Satellites and Dust Belts Around Asteroids: Negative Results", Abstracts of the Lunar and Planetary Science Conference, vol. 19, pp. 405–406, Bibcode:1988LPI....19..405G.
^Pilcher, Frederick (January 2013). "Lightcurves and Derived Rotation Periods for 18 Melpomene 38 Leda, and 465 Alekto". Bulletin of the Minor Planets Section of the Association of Lunar and Planetary Observers. 40 (1): 33. Bibcode:2013MPBu...40...33P.