Alpha Centauri B

Alpha Centauri B, also known as Toliman, is the secondary star of the binary system. It is a main-sequence star of spectral type K1 V, making it more an orange colour than Alpha Centauri A; it has around 90 percent the mass of the Sun and a 14 percent smaller diameter. Although it has a lower luminosity than A, Alpha Centauri B emits more energy in the X-ray band. Its light curve varies on a short time scale, and there has been at least one observed flare. It is more magnetically active than Alpha Centauri A, showing a cycle of 8.2±0.2 yr compared to 11 years for the Sun, and about half the minimum-to-peak variation in coronal luminosity of the Sun. Alpha Centauri B has an apparent magnitude of +1.35, slightly dimmer than Mimosa.