Antares (Alpha Scorpii) is the brightest star in the constellation Scorpius and one of the brightest stars in the night-time sky.  Approximately 600 light years from Earth, Antares is a class M supergiant star. It has a diameter of 800 million km - if it were in our solar system, it would more than encompass the orbit of Mars and reach about halfway to Jupiter. Antares has a hot blue companion star (Antares B).

Antares has appeared frequently in Star Trek. In the original series, it is the home of Antarean brandy and Antarean glow water. Starfleet's Antares Ship Yards are supposed to be located at Antares IV. It features in the romantic ballad sung by Lieutentant Uhura in the episodes "The Conscience of the King" and again in "The Changeling." 

Located in the star system is  some sort of stormy astronomical phenomenon called the Antares maelstrom. In the movie Star Trek II: The Wrath of Khan, Khan Noonien Singh swore he would chase Admiral James T. Kirk "round the moons of Nibia and round the Antares maelstrom and round perdition's flames" before he gave him up.
This maelstrom may indeed be a reference to fierce stellar winds blowing from the surface of Antares that have been observed in real astronomy. These stellar winds - massive versions of our Sun's own solar flares - have resulted in a circum-stellar gas cloud enveloping the system, which is illuminated by the light from Antares' hot B-type companion star.

Antares is the massive star in the yellow cloud
at the top left corner. Antares is an old star near the
end of its life and massive enough to explode in a supernova explosion, leaving a neutron star and an
expanding cloud of gas