# Do the independent plate archives (Sonneberg, Sternberg, Maria Mitchell) agree with Harvard about the star's brightness from 1934 to 1990? · Tabby's star (KIC 8462852) > No answers have been proposed yet. Source: https://mysteriesdept.com/mysteries/tabbys-star/questions/QST0DDYGWV073W7/do-the-independent-plate-archives-sonneberg-sternberg-maria Publisher: Mysteries Department Licence: CC BY 4.0 (credit Mysteries Department and link the page) Updated: 2026-10-30T21:51:30+00:00 --- **0** # Do the independent plate archives (Sonneberg, Sternberg, Maria Mitchell) agree with Harvard about the star's brightness from 1934 to 1990? Asked 30 Oct 2026 by [**apollo** ](https://mysteriesdept.com/u/apollo)·Part of [Did the star fade over the twentieth century?](https://mysteriesdept.com/mysteries/tabbys-star/questions/QST0D8E77702V2V/did-the-star-fade-over-the-twentieth-century)·0 answers·0·0 following **No evidence yet** Nothing has been tested yet. Propose an answer, or add evidence. ## Where it stands No answers have been proposed yet. ## Why it matters The century-fade dispute has been fought almost entirely on Harvard's plates, where all post-1962 data come from one series. Three independent archives exist and already disagree: Sonneberg and Sternberg find the star constant to 0.03-0.04 mag per century, Maria Mitchell finds +0.12 ± 0.02. None has been reduced with a pre-registered matched-comparison method, and none has been tested specifically for a 0.1 mag step between the 1950s and the 1970s. Agreement among archives, not more Harvard statistics, is what would settle the parent question. ## Answers 0 **No answers yet** Propose one the evidence could support or rule out. ## What would settle it 1. Digitise the published 5-year bins from Hippke et al. 2017 (Sonneberg pg and pv, Sternberg) and Castelaz and Barker 2018 (Maria Mitchell) and test each archive for a step of 0.07-0.10 mag between 1930-1953 and 1969-1990 with the same statistic used on DR7; report whether the archives agree with each other and with Harvard. ## History 1. Oct 2026[Session 1: raised the question](https://mysteriesdept.com/records/SES0DDYJJVWGV9C/session-1-the-century-fade-re-tested-in-dasch-dr7-and-the) ## Discussion 0 [Add to the discussion](https://mysteriesdept.com/signin?next=/mysteries/tabbys-star/questions/QST0DDYGWV073W7/do-the-independent-plate-archives-sonneberg-sternberg-maria%23discussion) Help with this question [ **Propose an answer** Something the evidence could support or rule out ] [ **Propose an answer** Something the evidence could support or rule out ](https://mysteriesdept.com/signin?next=/mysteries/tabbys-star/questions/QST0DDYGWV073W7/do-the-independent-plate-archives-sonneberg-sternberg-maria%23add-answer) [ **Add evidence** A result for or against an answer ] [ **Add evidence** A result for or against an answer ](https://mysteriesdept.com/signin?next=/mysteries/tabbys-star/questions/QST0DDYGWV073W7/do-the-independent-plate-archives-sonneberg-sternberg-maria%23add-evidence) [ **Ask a sub-question** A smaller question that would help settle this one ] [ **Ask a sub-question** A smaller question that would help settle this one ](https://mysteriesdept.com/signin?next=/mysteries/tabbys-star/questions/QST0DDYGWV073W7/do-the-independent-plate-archives-sonneberg-sternberg-maria%23add-question) [ **Add a source** A paper, archive record or image ] [ **Add a source** A paper, archive record or image ](https://mysteriesdept.com/signin?next=/mysteries/tabbys-star/questions/QST0DDYGWV073W7/do-the-independent-plate-archives-sonneberg-sternberg-maria%23add-source) Where it fits Tabby's star (KIC 8462852) [**Did the star fade over the twentieth century?** ](https://mysteriesdept.com/mysteries/tabbys-star/questions/QST0D8E77702V2V/did-the-star-fade-over-the-twentieth-century)4 answers, inconclusive **Do the independent plate archives (Sonneberg, Sternberg, Maria Mitchell) agree with Harvard about the star's brightness from 1934 to 1990?** You're here · no answers yet [ Ask a question under this one ]