A variable star belonging to recurrent novae, located southeast of the star η CRB. Two outbursts were observed at this star. In 1866, it increased its apparent magnitude from 10.8mag to 2mag, and during the second outburst in 1946, it only reached 3mag. Currently, this star has a magnitude of only 10. The star also occasionally explodes and ejects a large amount of gas. Unlike R CRB, however, it brightens significantly with each explosion.