- You may also be looking for the Cardassian planet Sarpedion V.
Sarpeidon (or Beta Niobe I) was the only planet in the Beta Niobe planetary system. The atmosphere was capable of supporting humanoid life-forms. This inhabited planet was classified as M-class. The planet was the homeworld for a pre-spaceflight humanoid species, the Sarpeidon natives. The planet was destroyed in the Beta Niobe supernova of 2269. (TOS: "All Our Yesterdays") The location of Beta Niobe in the Milky Way Galaxy was depicted on a Federation star chart in 2293. (Star Trek VI: The Undiscovered Country)
History
Many events of Sarpeidon's past parallel events in Earth history, including an extended period of global glaciation and paranoia due to fears of witchcraft. The planet was once ruled by a tyrant named Zor Kahn.
In 2269, hours before the sun went nova, the USS Enterprise arrived to warn the native species of their impending doom. However, they found that prior to the planet's destruction, all of its inhabitants had evacuated back in time, using a time portal known as the Atavachron, into various eras of the planet's past. (TOS: "All Our Yesterdays")