The Mestiko system (or Hertex system) was a star system in sector 418-D proximate to both Federation and Klingon space.
History and specifics
It consisted of the star Hertex, and seven planets, including one class M world, Mestiko, which had two moons, Varnex and Kifau.
By 2265, the Payav, the natives of Mestiko, had explored four of their system's other planets via automated space probes, and also established a permanent research base on Varnex.
In that year, the rogue pulsar PSR 418-D/1015.3 passed through the Mestiko system, causing numerous deaths and significant environmental damage to Mestiko, despite the efforts of Federation scientist Lindsey Cameron and the crew of the USS Enterprise. (TOS - Mere Anarchy eBook: Things Fall Apart)
The gravitation disruption altered the orbits of almost all the bodies of the system: the three outermost planets were torn from orbit; Daroken, the next planet out from Mestiko was brought to within eight million kilometers of Mestiko; and Kifau was pulled from Mestiko's orbit to become an independent planetoid. (TOS - Mere Anarchy eBook: The Darkness Drops Again)
- These descriptions of the Mestiko system seem to suggest Mestiko was its third planet; however, this is never specifically stated in any of the Mere Anarchy installments.