Credit: ©The Royal Society
    Image number: RS.15577

    Prediction of sunspots

    Date
    November 1676
    Creator
    Unknown, Artist
    Object type
    Archive reference number
    Manuscript page number
    p8
    Material
    Technique
    Dimensions
    height (page): 357mm
    width (page): 228mm
    Subject
    Content object
    space
       > Solar system
          > Sun
    Description
    A print of Cassini's prediction of the appearance of the sunspots in November 1676, which he exhibited to the Royal Academy of Sciences in Paris. It was included in a small separate tract, 'Description du mouvement que doit faire dans le Soleil une Tache sur la fin de Novembre 1676', sent with Cassini's letter to Henry Oldenburg dated 25 November 1676.

    This is a variant of EL/C1/65/003 with the observed positions (marked with a cross), which are close to Cassini's predicted positions (see Correspondence of Henry Oldenburg, ed. by Hall and Hall, vol. 13, p. 136n3).
    Transcription
    Maculae in Sole appariturae a die 18 ad 30 Novembris 1676 vestigium proximum

    Additis locis deinde observatis hoc Signo + notaris, ad Parallelum Solis variabilem, et Eclipticam immobilem reductis

    Die 16 Decembris macula querenda ad punctum inter 18, et 19 et diebus Sequentibus ad alia puncta inter numeros
    Transcribed by the Making Visible project
    Object history
    J. D. Cassini, ‘Observation of Sun spot and Saturn’, Phil. Trans. vol. 11, no. 128 (August and September 1676), pp. 689-90 (ref. to Tab II, figs 2 & 3, p. 689; ref. to Tab II, fig. 4, p. 690).
    Related fellows
    Jean Dominique Cassini (1625 - 1712, Italian) , Astronomer, Astronomer
    Henry Oldenburg (1612 - 1677, German) , Scientific correspondent
    Associated place
    <The World>
       > Europe
          > France
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