In ancient times, people saw a competitor in this star, the counterpart of Mars (anti-Ares: against Mars), as the strikingly red star strongly resembles the "Red Planet". The old Arabic name Kal al Akrab is no longer used, but the Latin designation Cor Scorpion - Heart of the Scorpion is derived from it. It lies at the intersection of the extended lines connecting the lateral sides of the Hercules quadrilateral. A greenish-colored physical companion with a brightness of 5.4 mag can be found at a separation of 2.9" best with a 200mm or larger telescope, as the glare of the main star is obstructive. A minimum magnification of 250x is recommended for visual resolution. The main component orbits approximately every 555 years.