The Antares maelstrom is an area of extreme radioactivity located inside the Antares system.
The use of the phrase Antares maelstrom is seen as a curse in the Federation. In 2268, an exasperated Ambassador Zarv used it as such when Captain Kirk stopped to help an alien vessel in distress, instead of rushing to an urgent diplomatic mission in the Ammdon system. In 2285, Khan Noonien Singh vowed that he would chase Kirk, "from the moon rings of Nubia, into the Antares maelstrom and 'round Perdition's flames", before giving up his quest for revenge. (TOS novel: Mutiny on the Enterprise; TOS movie: The Wrath of Khan)