Lambda Draconis (λ Draconis, abbreviated Lam Dra, λ Dra), also named Giausar ( ), is a solitary, orange-red star in the northern circumpolar constellation of Draco. It is visible to the naked eye with an apparent visual magnitude of around +3.8. Based upon an annual parallax shift of 9.79 mas as seen from the Earth, the star is located around 333 light years from the Sun.
This is an evolved red giant star on the asymptotic giant branch with a stellar classification of M0III-IIIa Ca1. It is a suspected slow irregular variable with a periodicity of roughly 1,100 days. It has an estimated 1.53 times the mass of the Sun and a measured radius of 70 times the radius of the Sun. It is radiating 884 times the solar luminosity from its photosphere at an effective temperature of 3,761 K.
Nomenclature λ Draconis (Latinised to Lambda Draconis) is the star's Bayer designation.
It bore the traditional name Giausar (also written as Gianfar, Giansar and Giauzar) and Juza. This name comes from the Persian term jauzahr, referring to the nodes of the Moon's (or any) orbit. In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN) to catalogue and standardize proper names for stars. The WGSN approved the name Giausar for this star on February 1, 2017, and it is now so included in the List of IAU-approved Star Names.
In Chinese, (), meaning Right Wall of Purple Forbidden Enclosure, refers to an asterism consisting of Lambda Draconis, Alpha Draconis, Kappa Draconis, 24 Ursae Majoris, 43 Camelopardalis, Alpha Camelopardalis and BK Camelopardalis. 中國星座神話, written by 陳久金. Published by 台灣書房出版有限公司, 2005, . Consequently, the Chinese name for Lambda Draconis itself is (, ), 香港太空館 - 研究資源 - 亮星中英對照表 , Hong Kong Space Museum. Accessed on line November 23, 2010. representing (), meaning First Minister.English-Chinese Glossary of Chinese Star Regions, Asterisms and Star Name , Hong Kong Space Museum. Accessed on line November 23, 2010. 上輔 (Shàngfǔ) was westernized into Sang Poo or Shaou Poo by R.H. Allen.
Namesakes USS Giansar (AK-111) was a United States Navy Crater class cargo ship named after the star.
References .