Xú Yuè 徐岳
Style name Gōnghé 公河. Native of Dōnglái 東萊 (modern Láizhōu in Shāndōng). Active late Hàn / early Wèi (active 220s CE). Birth and death years not securely recorded.
The Jìnshū Lǜlì zhì records that “Wú zhōngshūlìng Kàn Zé received Liú Hóng’s Qiánxiàngfǎ from Xú Yuè of Dōnglái” — locating Xú Yuè as one of the principal late-Hàn / early-Wèi astronomical-mathematical specialists. Liú Hóng (劉洪) was the great late-Hàn calendrical-astronomer-author of the Qiánxiàng lì 乾象曆; Xú Yuè was Liú Hóng’s student and through him Kàn Zé 闞澤 (the Wú-period bureaucrat) received the technique.
The 提要 of KR3f0034 Shùshù jìyí 數術記遺 — traditionally attributed to Xú Yuè — observes that the Wèi Huángchū (220–227 CE) Tàishǐchéng Hán Yì 韓詡 disputed-and-debated with Xú Yuè on five matters of solar-and-lunar eclipses, suggesting Xú Yuè was actively at court under the Wèi (post-Hàn) and so cannot be classified strictly as 漢. The Sìkù 提要 of KR3f0034 judges the traditional attribution of KR3f0034 Shùshù jìyí to Xú Yuè to be a Tang-period pseudepigraphic ascription rather than an authentic work — but Xú Yuè’s own historical existence as a late-Hàn / Wèi mathematician-astronomer is not in doubt.