Sarpeidon (or Beta Niobe I) was a planet located somewhere in the space of the galaxy's Alpha or Beta Quadrants, the sole planet in orbit of the Beta Niobe star system and the homeworld of the Sarpeid civilization. Formerly a class M planet, Sarpeidon was destroyed when its sun went supernova in the year 2269. Captain James T. Kirk, Commander Spock, and Doctor Leonard McCoy spent brief periods in the planet's past while ensuring the world had been evacuated. (TOS episode: "All Our Yesterdays")