Hypnos Hypnos In Greek mythology, Hypnos (; , "sleep") is the personification of sleep; the Roman equivalent is known as Somnus. In the Greek mythology, Hypnos is the son of Nyx ("The Night") and Erebus ("The Darkness"). His brother is Thanatos ("Death"). Both siblings live in the underworld ("Hades") or in Erebus, another valley of the Greek underworld. According to rumors, Hypnos lived in a big cave, which the river Lethe ("Forgetfulness") comes from and where night and day meet. His bed is made of ebony, on the entrance of the cave grow a number of poppies and other hypnotic plants.
14827 Hypnos the nucleus of an extinct comet that is covered by a crust several centimeters thick that prevents any remaining volatiles from outgassing. "Hypnos" is an assumed carbonaceous C-type asteroid. As of 2018, no rotational lightcurve of "Hypnos" has been obtained from photometric observations. The asteroids rotation period and spin axis remains unknown. It has a low brightness amplitude of 0.05 magnitude which indicates that the body has a rather spheroidal shape. According to the NEOSurvey carried out by NASA's Spitzer Space Telescope, "Hypnos" measures 520 meters in diameter and its surface has an albedo of 0.22 based on an absolute