Lambda Columbae is a probable binary star in the southern constellation of Columba. Its name is a Bayer designation that is Latinized from λ Columbae, and abbreviated Lambda Columbae or λ Col. With an apparent visual magnitude of 4.88, it is faintly visible to the naked eye. The measured annual parallax shift of yields an estimated distance of approximately . It is drifting further away from the Sun with a line of sight velocity component of +30 km/s.
Lambda Columbae has a stellar classification of B5 V, indicating that it is a B-type main sequence star. It is a suspected rotating ellipsoidal variable with a period of 0.64 days and an amplitude of 0.07 magnitude. Confirmation would indicate that this is a close binary system.
This star has an estimated age of around 57 million years with a relatively high rate of spin, showing a projected rotational velocity of 88 km/s. It has 4.3 times the mass of the Sun and 2.7 times the Sun's radius. Lambda Columbae is radiating 343 times the luminosity of the Sun from its photosphere at an effective temperature of 15,057 K.
In Chinese, (), meaning Son, refers to an asterism consisting of λ Columbae and β Columbae. Consequently, λ Columbae itself is known as (, ). From this Chinese name, the name Tsze is derived.
References 中國星座神話, written by 陳久金. Published by 台灣書房出版有限公司, 2005, .
AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 16 日