Nam Byeong-gil

Nam Byeong-gil (, 1820–1869), also known as Nam Sang-gil (南相吉, 남상길), courtesy name Jasang, art name Yugiljae or Hyecheon , was a Korean mathematician and astronomer of the Joseon period. He was a member of the Uiryeong Nam clan. His brother Nam Byeong-cheol (南秉哲) was also a noted astronomer.

His works included:
 * Siheon giyo (時憲紀要)
 * Seonggyeong (星鏡)
 * Yangdo uidoseol (量度儀圖說)
 * Chubo cheoprye (推步捷例)
 * Chiljeong bobeop (七政步法)
 * Taeyang chulippyo (太陽出入表)
 * Seonhak jeongui (算學正義)
 * Seontaek giyo (選擇紀要)
 * Jungseong sinpyo (中星新表)
 * Chunchu ilsiggo (春秋日食攷)