Nu Boötis Explained

The Bayer designation Nu Boötis (ν Boo / ν Boötis) is shared by two star systems, in the constellation Boötes:

• ν¹ Boötis
• ν² Boötis

They are separated by 0.17° on the sky. They have almost identical visual magnitudes, but contrasting colours: ν¹ is a yellow giant star, while ν² is a close binary with two white main sequence stars.

Both stars were members of asterism 七公 (Qī Gōng), Seven Excellencies, Heavenly Market enclosure.^[1]

Ptolemy considered Nu Boötis to be shared by Hercules, and Bayer assigned it a designation in both constellations: Nu Boötis (ν Boo) and Psi Herculis (ψ Her). When the modern constellation boundaries were fixed in 1930, the latter designation dropped from use.^[2]

Notes and References

1. AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 6 月 26 日
2. Web site: Bayer's Uranometria and Bayer letters . 2012-05-18 . 2019-03-15 . https://web.archive.org/web/20190315021210/http://ianridpath.com/startales/bayer.htm . dead .