Passage: The brightest component of the system, Sigma Scorpii Aa, is a double-lined spectroscopic binary, which means that the pair has not been resolved using a telescope. Instead, their orbit is determined by changes in their combined spectrum caused by the Doppler shift. This indicates that the pair complete an orbit every 33.01 days and have an orbital eccentricity of 0.32.The primary component of the spectroscopic binary, Sigma Scorpii Aa1, is an evolved giant star with a stellar classification of B1 III. It has around 18 times the mass of the Sun and 12 times the Sun's radius. This star is radiating about 29000 times the luminosity of the Sun from its outer envelope at an effective temperature of 26150 K. This is a variable star of the Beta Cephei type, causing the apparent magnitude to vary between +2.86 and +2.94 with multiple periods of 0.2468429, 0.239671, and 8.2 days. During each pulsation cycle, the temperature of the star varies by 4000±2000 K. The other member of the core pair, Sigma Scorpii Aa2, is a main sequence star with a classification of B1 V.Orbiting this binary at a separation of half an arcsecond, or at least 120 Astronomical units (AU), four times the Sun–Neptune distance, is the magnitude +5.2 Sigma Scorpii Ab, which has an orbital period of over a hundred years. Even farther out at 20 arcseconds, or more than 4500 AU, is Sigma Scorpii B with a magnitude of +8.7. It is classified as a B9 dwarf.

Question: What kind of star is this?
This is a variable star of the Beta Cephei type