Castor

Introduction
Castor, also known as α Gem, 66 Geminorum, FK5 287, Gliese 278, HIP 36850 and SAO 60198, is a sextuple star system located inside The Gemini Constellation. Castor is in fact, the second brightest object from The Gemini Constellation. The Six Star that compose of Castor are Castor Aa, Castor Ab, Castor Ba, Castor Bb, Castor Ca and Castor Cb. 
Castor A
Castor Aa and Castor Ab, also known as, BD+32°1581A, PLX 1785.00, HR 2891 and HD 60179, has a mass of 2.76 Solar Masses and a radius of 2.4 Solar Radiuses. Castor Aa and Castor Ab has a surface gravity of 4.2 centimeter-gram-second system of units and a temperature of 10,286 Kelvin.
Castor B
Castor Ba and Castor Bb, also known as, BD+32°1581B, HR 2890 and HD 60178, has a mass of 2.98 Solar Masses and a radius of 3.3 Solar Radiuses. Castor Ba and Castor Bb has a surface gravity of 4 centimeter-gram-second system of units and a temperature of 8842 Kelvin. 
Castor C
Castor Ca and Castor Cb, also known as YY Geminorum and BD +32° 1582, has a mass of 0.5992 Solar Masses, a radius of 0.6191 Solar Radiuses and a luminosity of 0.0733 Solar Luminosities. Castor Ca and Castor Cb has a surface gravity of 4.6317 centimeter-gram-second system of units and a temperature of 3820 Kelvin. Castor Ca and Castor Cb is 370 Million Years Old.