I became aware of the Cosmos Magazine article The unforgotten sisters: Sonduk, the astronomer queen (hereinafter “Cosmos Magazine article,” archived version https://archive.is/j7d1n ) from somewhat implausible claims about the ancient Korean monarch Seondeok (善德王) being discussed as fact on social media. I found out the article was adapted from an earlier book by the same author, Gabriella Bernardi's The Unforgotten Sisters: Astronomers and Scientists before Caroline Herschel (2016 Springer Praxis, hereinafter “Unforgotten Sisters”) and started tracking down possible sources of these claims starting with the bibliography of Bernardi's book.

Suspicions about these claims and subsequent research were recorded contemporaneously on a thread on writeout.ink. This page and linked pages are a more formal documentation of the findings.

• Yung-Chung Kim, Women of Korea: A History from Ancient Times to 1945 (2nd ed. 1977)
  • Index of Queen Sŏndŏk references: 23, 24, 27, 42 (Apparent mistake for 25, 26, 27, 42)

This book (hereinafter “Women of Korea”) was cited in the bibliography of Unforgotten Sisters and I read the parts relevant to Seondeok as a possible source for the unusual claims. However, Women of Korea does not go beyond the known historical information on Seondeok and I could not find any mention of details unique to Unforgotten Sisters such as her passion for astronomy, having a Tang ambassador as a tutor, etc. See Passages on Seondeok from Women of Korea (1977).

• Sheri Holman, Sŏndŏk: Princess of the Moon and Stars (2002)

Not directly cited in Unforgotten Sisters and found by independent search, this middle-grade novel (hereinafter “Princess of the Moon and Stars”) has many striking similarities with the assertions about Seondeok that I could not trace to any historical source. There are even passages with very similar wording. See Comparison with Princess of the Moon and Stars.

I have looked through four other sources that might be relevant to Seondeok and that I had library access to, mostly biographical dictionaries of astronomers and scientists. I could not find any mention of her, however.

I also read the Seondeok chapter of Bernardi's Unforgotten Sisters and found it had the same problems as the Cosmos Magazine article: Similar in substance, no labeling of fictional content in a book meant to be non-fiction, and no mention or citation of Holman's novel,

• The claims about Seondeok not found in the recorded history appear to be drawn uncited and uncredited from the novel Princess of the Moon and Stars.
• The chapter in Unforgotten Sisters and the Cosmos Magazine article should be retracted or corrected to remove the fictional material.
• If the chapter and article are left as they are, they should be marked or otherwise notified as largely fictional, and Ms. Holman's permission should be sought for the use of details she originated, with appropriate credit. She may also be due some form of apology, acknowledgement, and recompense.