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An analysis of medieval solar theories

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Abstract

From Antiquity through the early modern period, the apparent motion of the Sun in longitude was simulated by the eccentric model set forth in Ptolemy’s Almagest III, with the fundamental parameters including the two orbital elements, the eccentricity e and the longitude of the apogee λA, the mean motion ω, and the radix of the mean longitude \( \bar{\lambda }_{0} \). In this article we investigate the accuracy of 11 solar theories established across the Middle East from 800 to 1600 as well as Ptolemy’s and Tycho Brahe’s, with respect to the precision of the parameter values and of the solar longitudes λ that they produce. The theoretical deviation due to the mismatch between the eccentric model with uniform motion and the elliptical model with Keplerian motion is taken into account in order to determine the precision of e and λA in the theories whose observational basis is available. The smallest errors in the eccentricity are found in these theories: the Mumtaḥan (830): − 0.1 × 10−4, Bīrūnī (1016): + 0.4 × 10−4, Ulugh Beg (1437): − 0.9 × 10−4, and Taqī al-Dīn (1579): − 1.1 × 10−4. Except for al-Khāzinī (1100, error of ~ + 21.9 × 10−4, comparable to Ptolemy’s error of ~ + 33.8 × 10−4), the errors in the medieval determinations of the solar eccentricity do not exceed 7.7 × 10−4 in absolute value (Ibn al-Shāṭir, 1331), with a mean error μ = + 2.57 × 10−4 and standard deviation σ = 3.02 × 10−4. Their precision is remarkable not only in comparison with the errors of Copernicus (− 7.8 × 10−4) and Tycho (+ 10.2 × 10−4), but also with the seventeenth-century measurements by Cassini–Flamsteed (− 2.4 × 10−4) and Riccioli (+ 5.5 × 10−4). The absolute error in λA varies from 0.1° (Taqī al-Dīn) to 1.9° (al-Khāzinī) with the mean absolute error MAE = 0.87°, μ = −0.71° and σ = 0.65°. The errors in λ for the 13,000-day ephemerides show MAE < 6′ and the periodic variations mostly remaining within ± 10′ (except for al-Khāzinī), closely correlated with the accuracy of e and λA.

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Notes

  1. For the bio-bibliographies of the astronomers mentioned in this study, see Gillipsie et al. (1970–1980), Koertge (2008), Hockey et al. (2007), Bearman et al. (1960–2005), Sezgin (1978), and Rosenfeld and İhsanoğlu (2003). For the Islamic astronomical tables mentioned in this article, see Kennedy (1956) and King et al. (2001). A comprehensive survey is in preparation by B. van Dalen in Munich.

  2. Toomer [1984] (1998, pp. 131–172); On the ancient solar theories, e.g., see Petersen and Schmidt (1968), Pedersen (1974, Chap. 3), Neugebauer (1975, Vol. 1, pp. 54–61), Jones (1991), Maeyama (1998), Duke (2008), and Swerdlow (2010).

  3. Toomer [1984] (1998, pp. 443, 453).

  4. For the astronomical and historical reasons behind these two frequently used values, see Mozaffari (2016a).

  5. See Table 1, note 9.

  6. Mozaffari (2017, pp. 10, 21–24).

  7. Toomer [1984] (1998, pp. 215–216).

  8. Bīrūnī (1954–1956, Vol. 2, p. 653).

  9. Swerdlow (2010, p. 155).

  10. Neugebauer (1962) and Moesgaard (1974).

  11. About these two medieval views, see Swerdlow (1975, p. 50).

  12. About the model and its later receptions and parameters, see Toomer (1969, 1987), Samsó and Millás (1989), Samsó (1987, 2011, pp. 207–218 and 491–492), and Calvo (1998).

  13. Copernicus (1543, ff. 90v–91r); see, also, Swerdlow and Neugebauer (1984, Vol. 1, pp. 157–161).

  14. Neugebauer (1975, Vol. 3, pp. 1097–1102).

  15. Maeyama (1998, pp. 4–8).

  16. From the formulae given in Simon et al. (1994, p. 678).

  17. See Mozaffari (2013).

  18. See Mozaffari (2013, Part 1, pp. 322, 326, Part 2, p. 393).

  19. Al-Maghribī’s text is translated and his procedure is explained in Saliba (1985).

  20. Mozaffari and Steele (2015, pp. 350–354).

  21. Copernicus (1543, ff. 87v–88v), Swerdlow and Neugebauer (1984, pp. 152–154). In his earlier work, De hypothesibus … commentariolus, Copernicus used e = 0.0189 (see Swerdlow 1973, p. 442) adopted from the Alfonsine Tables (see Goldstein and Chabás 2001; Chabás and Goldstein 2003, pp. 153–155).

  22. Brahe (1913–1929, Vol. 2, pp. 19–28), Opera Omnia. See Dreyer (1890, p. 333), Moesgaard (1975, pp. 85–89), Thoren and Christianson (1990, pp. 223–224), and Swerdlow (2010, p. 155). On Tycho’s solar measurements I did also have the chance to access to Prof. N. Swerdlow’s blow-by-blow quantitative analysis of these matters, which will soon appear in his study of Renaissance astronomy.

  23. Tycho’s solar theory was completed by early 1589, but most of his solar observations were made in the period 1588–1591 and 1595; for an analysis of them, see Wesley (1979).

  24. From Tables in Brahe (1913–1929, Vol. 2, pp. 46–47), Opera Omnia.

  25. See Mozaffari (2013, Part 1, pp. 322, 326, Part 2, pp. 393, 399).

  26. Flamsteed (1674b, p. 221). In the case of Mars, see Wilson (1969).

  27. Hornsby (1763, p. 467).

  28. Ricciloi (1665, I.9–10: pp. 29–33).

  29. Kepler’s (1570–1858) Epitomes Astronomiae Copernicanae VI: Opera Omnia, Vol. 6, p. 433.

  30. Bullialdus (1645, pp. 53–57).

  31. Ricciloi (1665, I.3: Vol. 1, pp. 13–14 (equinoxes); I.5: Vol. 1, p. 18 (solstices); I.8: Vol. 1, pp. 26–29 (noon-altitudes)).

  32. Flamsteed (1674b, p. 220–221).

  33. Flamsteed (1674a, p. 6000).

  34. Toomer [1984] (1998, pp. 255–257).

  35. Toomer [1984] (1998, p. 265).

  36. See Swerdlow (1972) and Van Helden (1985, pp. 31–32).

  37. Ibn Yūnus, Zīj, F1: ff. 60v–61r, 77r–v.

  38. See Delambre (1819, pp. 149–150), Hartner (1980), and King (1999, p. 502).

  39. Al-Maghribī, Talkhīṣ al-majisṭī VI.6–7: ff. 93v–95v.

  40. Ibn al-Shāṭir, Jadīd zīj, O: ff. 86v–87r.

  41. See Roberts (1957, pp. 429–430).

  42. Kāshī, Sullam al-samā’ (The stairway to the heavens), f. 8v; Zīj, IO: f. 185r.

  43. Ulugh Beg, Zīj, P1: f. 108r, 125v, 130v, P2: f. 119v, 140v, 148v.

  44. Nallino [1899–1907] (1969, Vol. 2, pp. 93–94).

  45. Al-Maghribī, Adwār, CB: f. 90v, M: f. 92v.

  46. Said and Stephenson (1995, p. 122).

  47. See Mozaffari (2013, Part 1, pp. 322, 328).

  48. Explained in Said and Stephenson (1995, 131n24).

  49. Ibn Yūnus, Zīj, L: p. 223, F1: f. 25r.

  50. Ibn Yūnus, Zīj, L: p. 224, F1: f. 25v.

  51. Ibn al-Shāṭir, Jadīd zīj, O: ff. 87v–88r. In the text of cap. 62: 2;50°, but in the table appended to it: 2;51°.

  52. This note is also appended as a brief separate chapter to MS. F1 of Ibn Yūnus’s Ḥākimī zīj (F1: f. 88v).

  53. Bernard (1684, p. 724). Bernard’s value 2;59° appears to be a typo of the value 2;50° Ibn al-Shāṭir gives in the explanatory text of cap. 62 of his zīj (see above, note 51). Hartner (1977, p. 5) informs us of this letter. Note that we have made use of the same manuscript Bernard did.

  54. Table of the solar declination in Ibn al-Shāṭir, Jadīd zīj, O: f. 139v.

  55. See Mozaffari (2013, Part 2, pp. 393, 395, 399).

  56. Meeus (2002, pp. 357–366).

  57. Neugebauer (1962, esp. pp. 283–285).

  58. Bīrūnī (1954–1956, Vol. 2, esp. pp. 668–669); also, see Hartner and Schramm (1961, p. 214f). That the lengths of the true solar years with respect to the ecliptic are varied is also mentioned in al-Ṭūsī’s Taḥrīr al-majisṭī (Exposition of the Almagest) as a comment on Almagest III.1 (P1: p. 88, P2: f. 24v, P3: f. 41r). For the translation of the relevant passage, see Saliba [1987] (1994, p. 148).

  59. Meeus (2002, p. 362).

  60. See Said and Stephenson (1995).

  61. Bīrūnī (1954–1956, Vol. 2, p. 648). Mozaffari (2016b, p. 269).

  62. Noted earlier in the case of al-Battānī in Thurston (2002, p. 59).

  63. See Grasshof (1990).

  64. Toomer [1984] (1998, pp. 452–453, 541). About the eras, see B. V. Dalen’s entry “Ta’rīkh” in EI 2 (Vol. 10, esp. p. 261).

  65. This should be 0;39,4 h because in Sidrat II.4 (K: f. 17v), Taqī al-Dīn asserts that from his observations of the triple of the lunar eclipses in 1576–1577 (see Mozaffari and Steele 2015), he derived the value 56;39,45° for the longitude of Istanbul from the Fortunate Islands; also, in Sidrat V.1 (K: f. 41v), where he converts the time of one of the lunar eclipses which Ptolemy observed at Alexandria to the meridian of Istanbul, he takes the meridian of Istanbul equal to 56;40° and that of Alexandria as 61;54°, and correctly states that the then resulted difference of 5;14° in terrestrial longitude between the two cities corresponds to a difference of 0;20,56 h in local times between the two. However, he appears to have discarded the value 56;39,45° for the longitude of Istanbul later, since the relevant lines on f. 17v are blacked out as well as in the geographical table attributed to him (see King 2004/5, Vol. 1, p. 449–450), the longitudes of Istanbul and Alexandria are given, respectively, 60;0° and 61;55°, both in accordance with other sources which have 59;50° for the longitude of Istanbul and 61;54° for that of Alexandria reckoned from the Fortunate Islands. Note that Istanbul (L = 28;57° from Greenwich) is actually only about one degree west of Alexandria (L = 29;55°). It deserves noting that the rounded value 56;40° is not unprecedented; it stems from Ptolemy’s Geography and is also used, e.g., in al-Battānī Ṣābi’ zīj (Nallino [1899–1907] 1969, Vol. 2, p. 44, Vol. 3, p. 239; also, see Kennedy 1960, p. 186).

  66. See Mozaffari (2017, p. 10, note 15).

  67. Ibn al-Shāṭir, Jadīd zīj, K: f. 2v, O: f. 2v, L1: f. 2r, L2: f. 2; Mozaffari (2017, p. 21).

  68. Petersen and Schmidt (1968, p. 84) and Neugebauer (1975, Vol. 1, pp. 275–276).

  69. Brahe, Progymnasmata I: Opera Omnia, Vol. 2, p. 15.

  70. From Walther’s observations of the solar meridian zenith distances, Tycho derives the following values for the solar orbital elements in 1488, a century before him, by means of the three-point method:

     

    e

    λ Α

    Applying the two equinoxes and mid-spring

    2;7,43

    94;15°

    Applying the two equinoxes and mid-summer

    2;7,44

    94;19

    According to Walther’s observations, the vernal equinox of 1488 occurred in Nuremburg on 11 March, 3;40h after midnight which converted to the meridian of Uraniborg (the place of Tycho’s observatory) is 3;55 h. Tycho computed the time of the vernal equinox of 1588 in Uraniborg as 10 March, 8;45 h after midnight. On the basis of the above values for the solar orbital elements, the equation of centre q at the instant of the vernal equinox of 1488 was equal to +2;1,35°. Also, according to Tycho’s values for e for 1588, at the time of the vernal equinox of 1588, q = +2;2,35°. Accordingly, the solar mean longitude at the time of the vernal equinox of 1488 was equal to 357;58,25° and at that of the vernal equinox of 1588: 357;57,25°. The mean sun travels 0;1° in about 0;25 h. Thus, the mean sun completed 100 revolution on the ecliptic in 100 Julian years (of 365.25 days unvarying) minus 1 d 3;55 h − (8;45 + 0;25) h. Therefore, the length of the solar year = 365 days 6 h – 18;45 h/100 = 365 days 5;48,45 h (see Tycho, Progymnasmata I: Opera Omnia, Vol. 2, pp. 40–44).

  71. Dreyer (1890, p. 333) asserts that Tycho’s value is “only about a second too small”, which appears to be the result of the comparison of Tycho’s value with the length of the tropical year at the time (365 days 5;48,47 h). This example illustrates how much determinative the difference between the various types of the solar years may be in carefully examining the precision of historical values.

  72. From the formula given for the mean longitude of the Earth in Simon et al. (1994, p. 678).

  73. See Mozaffari (2014, pp. 110–112).

  74. Taqī al-Dīn, Kharīdat, B: ff. 26v–28v, C1: ff. 48r–51r, C2: ff. 34r–38r, E: ff. 2v–4v, 53r, K: ff. 45v–49r.

  75. Al-Khāzinī, Zīj, L: f. 105v.

  76. E.g., see Mozaffari (2016a, pp. 307–308).

  77. See Mozaffari (2016b, esp. p. 270).

  78. Ibn Yūnus, Zīj, L: pp. 98–99; Caussin (1804, pp. 104–107), and Delambre (1819, p. 83).

  79. Bīrūnī (1954–1956, Vol. 2, pp. 642–643, 647–648).

  80. See Mozaffari and Zotti (2013, pp. 57–58).

  81. Said and Stephenson (1995, pp. 125, 130).

  82. Maeyama (1998, p. 39).

  83. See, also, Said and Stephenson (1995, pp. 120–121).

  84. See Mozaffari (2013, Part 1: pp. 317–321).

  85. Flamsteed (1674b, p. 221).

  86. Seemann (1929, pp. 28–32); for an illustration, see Sezgin and Neubauer (2010, Vol. 2, p. 38). On the instruments of the Maragha observatory in detail, see Mozaffari and Zotti (2013).

  87. Taqī al-Dīn, Sidrat, K: ff. 14v–15v, N: ff. 18r–19v, V: ff. 22r–23v; Sezgin and Neubauer (2010, Vol. 2, pp. 53–54).

  88. Knobel (1917).

  89. See Piini (1986, pp. 542–543).

  90. For the analysis of Ulugh Beg’s star catalogue, see Shevchenko (1990), Krisciunas (1994), and Verbunt and van Gent (2012).

  91. See Mozaffari (2016c, esp. pp. 522, 525).

  92. Mozaffari (2016a, pp. 307–308).

  93. Mozaffari (2016a, pp. 296–297). The non-Ptolemaic star table in the Īlkhānī zīj is also available on http://cdsarc.u-strasbg.fr/viz-bin/Cat?J/other/JHA/47.294. Ibn Yūnus’s star table will be discussed in detail in a forthcoming paper by the present author.

References

  • Bearman, P., Bianquis, Th., Bosworth, C.E., van Donzel, E., and Heinrichs, W.P., 1960–2005. [EI 2:] Encyclopaedia of Islam, 2nd edn., 12 vols. Leiden: Brill.

  • Bernard, Edward. 1684. The Observations of the Ancients Concerning the Obliquity of the Zodiac, in a Letter of Mr. Edward Bernard to Mr. John Flamsteed Math. Reg. Philosophical Transactions of the Royal Society 14: 721–725.

    Article  Google Scholar 

  • al-Battānī, Abū ‘Abd-Allāh Muḥammad b. Jābir b. Sinān al-Ḥarrānī, Zīj al-Ṣābi’ (The Sabean Zīj), MS. E: Biblioteca Real Monasterio de San Lorenzo de el Escorial, no. árabe 908 (also, see Nallino [1899–1907] 1969). Translated into Latin by Plato of Tivoli in Barcelona in the 12th century, printed twice, in Nuremberg in 1537 (with Farghānī’s work) and in Bologna in 1645.

  • al-Bīrūnī, Abū al-Rayḥān, 1954–1956. al-Qānūn al-mas‘ūdī (Mas‘ūdīc canons), 3 vols. Hyderabad: Osmania Bureau.

  • Brahe, T., 1913–1929. Tychonis Brahe Dani Opera Omnia, ed. J.L.E. Dreyer, 15 vols. Copenhagen: Libraria Gyldendaliana.

  • Bullialdus, Ismaël, 1645. Astronomia Philolaica. Paris.

  • Caussin de Perceval, J.-J.-A. 1804. Le livre de la grande table hakémite, Observée par le Sheikh,…, ebn Iounis. Notices et Extraits des Manuscrits de la Bibliothèque nationale 7: 16–240.

    Google Scholar 

  • Chabás, J., and B.R. Goldstein. 2003. The Alfonsine tables of Toledo. Dordrecht: Kluwer Academic Publishers.

    Book  MATH  Google Scholar 

  • Copernicus, N., 1543. De revolutionibus orbium coelestium, Nuremberg. On the Revolutions of the Heavenly Spheres, Wallis, C.G. (tr.), Annapolis: St John’s College Bookstore, 1939. Rep. The Great Books of the Western World, 2nd edn. Chicago: Encyclopædia Britannica, 1990, vol. 15.

  • Calvo, Emilia. 1998. Astronomical Theories Related to the Sun in Ibn al-Hā’im’s al-Zīj al-Kāmil fī’l-Ta‘ālīm. Zeitschrift für Geschichte der Arabisch-Islamischen Wissenschaften 12: 51–111.

    MathSciNet  MATH  Google Scholar 

  • Debarnot, M.-T. 1987. The Zīj of Ḥabash al-Ḥāsib: A Survey of MS Istanbul Yeni Cami 784/2. In From Deferent to Equant: A Volume of Studies on the History of Science of the Ancient and Medieval Near East in Honor of E. S. Kennedy, eds. Saliba, G. and King, D. A., 1987, vol. 500, 35–69. Annals of the New York Academy of Sciences.

  • Delambre, M. 1819. Histoire de l’Astronomie du Moyen Age. Paris: Courcier.

    MATH  Google Scholar 

  • Dreyer, J.L.E. 1890. Tycho Brahe: A Picture of Scientific Life and Work in the Sixteenth Century. Edinburgh: Adam and Charles Black.

    MATH  Google Scholar 

  • Duke, D. 2008. Four Lost Episodes in Ancient Solar Theory. Journal for the History of Astronomy 39: 283–296.

    Article  Google Scholar 

  • Flamsteed, John. 1674a. Johannis Flamstedii derbiensis angli ad clarissimum Cassinum epistola, novas observationes extimarum elongationum siderum Medicæorum à centro jovis, novâ sed & accuaratâ ratione habitas, exhibens; adjectis quibusdam observationibus non-vulgaribus, planetarum diametros & à fixis distantias, nec non martis acronici & perigei parallaxin, &c spectantibus. Philosophical Transactions of the Royal Society 8: 6094–6000.

    Google Scholar 

  • Flamsteed, John. 1674b. Extracts of Two Letters, Written by Mr. Flamsteed to Mr. Collins …. Philosophical Transactions of the Royal Society 9: 219–221.

    Article  Google Scholar 

  • Gillipsie, C.C. et al. (ed.), 1970–1980. [DSB:] Dictionary of Scientific Biography, 16 vols. New York: Charles Scribner’s Sons.

  • Goldstein, B.R., and J. Chabás. 2001. The Maximum Solar Equation in the Alfonsine Tables. Journal for the History of Astronomy 32: 345–348.

    Article  MathSciNet  Google Scholar 

  • Grasshoff, G. 1990. The History of Ptolemy’s Star Catalogue. New York: Springer.

    Book  MATH  Google Scholar 

  • Ḥabash al-Ḥāsib, The zīj of Ḥabash al -Ḥāsib, MSS. B: Berlin, Ahlwardt 5750 (formerly Wetzstein I 90); I: Istanbul, Süleymaniye, Yeni Cami, no. 784.

  • Hartner, W. 1977. The Role of Observations in Ancient and Medieval Astronomy. Journal for the History of Astronomy 8: 1–11.

    Article  MathSciNet  Google Scholar 

  • Hartner, W. 1980. Ptolemy and Ibn Yūnus on Solar Parallax. Archives Internationales d’Histoire des Sciences 30: 5–26.

    MathSciNet  Google Scholar 

  • Hartner, W. and Schramm, M. 1961. Al-Bīrūnī and the Theory of the Solar Apogee: An Example of Originality in Arabic Science. In Scientific Change. Historical Studies in the Intellectual, Social and Technical Conditions for Scientific Discovery and Technical Invention, from Antiquity to the Present, ed. A.C. Crombie. Symposium on the History of Science, University of Oxford 9–15 July 1961), London: Heinemann, 206–218.

  • Hockey, T., et al. (eds.). 2007. [BEA:] The Biographical Encyclopedia of Astronomers. Berlin: Springer.

    Google Scholar 

  • Hornsby, Thomas. 1763. A Discourse on the Parallax of the Sun. Philosophical Transactions of the Royal Society 53: 467–495.

    Article  Google Scholar 

  • Ibn al-Shāṭir, ‘Alā’ al-Dīn Abu’l-Ḥasan ‘Alī b. Ibrāhīm b. Muḥammad al-Muṭa‘‘im al-Anṣārī, al-Zīj al-Jadīd, MSS. K: Istanbul, Kandilli Observatory, no. 238, O: Oxford, Bodleian Library, no. Seld. A inf 30, D: Damascus, Asad National library, no. 3093; L1: Leiden, Universiteitsbibliotheek, no. Or. 65; L2: Leiden, Universiteitsbibliotheek, Or. 530; PR: Princeton, Princeton University Library, no. Yahuda 145.

  • Ibn Yūnus, ‘Alī b. ‘Abd al-Raḥmān b. Aḥmad, Zīj al-kabīr al -Ḥākimī, MSS. L: Leiden, Universiteitsbibliotheek, no. Or. 143, O: Oxford, Bodleian Library, no. Hunt 331, F1: Paris, Bibliothèque Nationale, no. Arabe 2496 (formerly, arabe 1112; copied in 973 H/1565–1566 AD), F2: Paris, Bibliothèque Nationale, no. Arabe 2495 (formerly, arabe 965; the 19th-century copy of MSS. L and the additional fragments in F1).

  • Jones, Alexander. 1991. Hipparchus’s Computations of Solar Longitudes. Journal for the History of Astronomy 22: 101–125.

    Article  MathSciNet  Google Scholar 

  • al-Kamālī, Muḥammad b. Abī ‘Abd-Allāh Sanjar (Sayf-i munajjim), Ashrafī zīj, MSS. F: Paris, Bibliothèque Nationale, no. 1488, G: Iran–Qum: Gulpāyigānī, no. 64731.

  • al-Kāshī, Jamshīd Ghiyāth al-Dīn, Sullam al-samā’, MS. Iran: National Library, no. 1174059, ff. 1v–15v (copied in Rajab 1277/January–February 1861).

  • al-Kāshī, Jamshīd Ghiyāth al-Dīn, Khāqānī zīj, MS. IO: London: India Office, no. 430; P: Iran: Parliament Library, no. 6198.

  • al-Khāzinī, ‘Abd al-Raḥmān, al-Zīj al-mu‘tabar al-sanjarī, MSS. V: Vatican, Biblioteca Apostolica Vaticana, no. Arabo 761, L: London, British Linbrary, no. Or. 6669; Wajīz [Compendium of] al-Zīj al-mu‘tabar al-sanjarī, MSS. I: Istanbul, Süleymaniye Library, Hamidiye collection, no. 859; S: Tehran: Sipahsālār, no. 682.

  • Kennedy, E.S. 1956. A Survey of Islamic Astronomical Tables. Transactions of the American Philosophical Society, New Series 46: 123–177.

    Article  MathSciNet  MATH  Google Scholar 

  • Kennedy, E.S. 1960. The Planetary Equatorium of Jamshīd Ghiyāth al-Dīn al-Kāshī. Princeton: Princeton University Press.

    Google Scholar 

  • Kennedy, E.S. 1977. The Astronomical Tables of Ibn al-A‘lam. Journal for the History of Arabic Science 1: 13–23.

    MathSciNet  Google Scholar 

  • Kennedy, E.S., and D. Pingree (eds.). 1981. The Book of the Reasons Behind Astronomical Tables. New York: Scholars’ Facsimiles & Reprints.

    Google Scholar 

  • Kepler, J., 1570–1858. Joannis Kepleri Astronomi Opera Omnia, ed. Ch. Frisch, 8 vols. Frankfurt-Erlangen.

  • King, D.A., 1999. Aspects of Fatimid Astronomy: From Hard-Core Mathematical Astronomy to Architectural Orientations in Cairo. In L’Égypte Fatimide: son art et son histoireActes du colloqie organisé à Paris les 28, 29 et 30 mai 1998, ed. M. Barrucand. Paris: Presses de l’Université de Paris-Sorbonne, 497–517. Rep. ed. King, D.A. 2012. Islamic Astronomy and Geography. Berlin: Farnham–Burlington, Trace IV.

  • King, D. A., 2004/5. In Synchrony with the Heavens; Studies in Astronomical Timekeeping and Instrumentation in Medieval Islamic Civilization, 2 vols. Leiden-Boston: Brill.

  • King, D.A., J. Samsó, and B.R. Goldstein. 2001. Astronomical Handbooks and Tables from the Islamic World (750–1900): An Interim Report. Suhayl 2: 9–105.

    MathSciNet  MATH  Google Scholar 

  • Koertge, N., 2008. [NDSB:] New Dictionary of Scientific Biography, 8 vols. Detroit: Charles Scribner’s Sons.

  • Krisciunas, K. 1994. A More Complete Analysis of the Errors in Ulugh Beg’s Star Catalogue. Journal for the History of Astronomy 24: 269–280.

    Article  Google Scholar 

  • Knobel, E.B. 1917. Ulugh Beg’s Catalogue of Stars. Washington: Carnegie.

    Google Scholar 

  • al-Maghribī, Mūḥyī al-Dīn, Adwār al-anwār, MS. M: Iran, Mashhad, Holy Shrine Library, no. 332; MS. CB: Ireland, Dublin, Chester Beatty, no. 3665.

  • al-Maghribī, Mūḥyī al-Dīn, Talkhīṣ al-majisṭī, MS. Leiden: Universiteitsbibliotheek, Or. 110.

  • Maeyama, Y. 1998. Determination of the Sun’s Orbit. Hipparchus, Ptolemy, al-Battânî, Copernicus, Tycho Brahe. Archive for History of Exact Sciences 53: 1–49.

    Article  MathSciNet  MATH  Google Scholar 

  • Meeus, Jean. 2002. More Mathematical Astronomy Morsels. Richmond: William-Bell.

    MATH  Google Scholar 

  • Mercier, R.P. 1989. The Parameters of the Zīj of Ibn al-A‘lam. Archives Internationales d’Histoire des Sciences 39: 22–50.

    MATH  Google Scholar 

  • Moesgaard, Kristian Peder. 1974. Thābit ibn Qurra Between Ptolemy and Copernicus: An Analysis of Thābit’s Solar Theory. Archive for History of Exact Sciences 12: 199–216.

    Article  MathSciNet  MATH  Google Scholar 

  • Moesgaard, Kristian Peder. 1975. Tychonian Observations, Perfect Numbers, and the Date of Creation: Longomontanus’s Solar and Precessional Theories. Journal for the History of Astronomy 6: 84–99.

    Article  MathSciNet  Google Scholar 

  • Mozaffari, S. Mohammad, 2013. Limitations of Methods: The Accuracy of the Values Measured for the Earth’s/Sun’s Orbital Elements in the Middle East, A.D. 800 and 1500. Journal for the History of Astronomy Part 1: 44(3), 313–336, Part 2: 44(4), 389–411.

  • Mozaffari, S. Mohammad. 2014. Muḥyī al-Dīn al-Maghribī’s Lunar Measurements at the Maragha observatory. Archive for History of Exact Sciences 68: 67–120.

    Article  MATH  Google Scholar 

  • Mozaffari, S. Mohammad. 2016a. A Medieval Bright Star Table: The Non-Ptolemaic Star Table in the Īlkhānī Zīj. Journal for the History of Astronomy 47: 294–316.

    Article  Google Scholar 

  • Mozaffari, S. Mohammad. 2016b. A Forgotten Solar Model. Archive for History of Exact Sciences 70: 267–291.

    Article  Google Scholar 

  • Mozaffari, S. Mohammad. 2016c. Planetary latitudes in medieval Islamic astronomy: an analysis of the non-Ptolemaic latitude parameter values in the Maragha and Samarqand astronomical traditions. Archive for History of Exact Sciences 70: 513–541.

  • Mozaffari, S. Mohammad, 2016–2017. A Revision of the Star Tables in the Mumtaḥan zīj. Suhayl 15: 67–100.

  • Mozaffari, S. Mohammad. 2017. Holding or Breaking with Ptolemy’s Generalization: Considerations About the Motion of the Planetary Apsidal Lines in Medieval Islamic Astronomy. Science in Context 30: 1–32.

    Article  Google Scholar 

  • Mozaffari, S. Mohammad, and Georg Zotti. 2013. The Observational Instruments at the Maragha Observatory after AD 1300. Suhayl 12: 45–179.

    Google Scholar 

  • Mozaffari, S.M., and G. Zotti. 2015. Bīrūnī’s Telescopic-Shape Instrument for Observing the Lunar Crescent. Suhayl 14: 167–188.

    Google Scholar 

  • Mozaffari, S.M., and J.M. Steele. 2015. Solar and Lunar Observations at Istanbul in the 1570s. Archive for History of Exact Sciences 69: 343–362.

    Article  MathSciNet  MATH  Google Scholar 

  • Nallino, C.A. (ed.), [1899–1907] 1969, Al-Battani sive Albatenii Opus Astronomicum. Publicazioni del Reale osservatorio di Brera in Milano, n. XL, pte. I–III, Milan: Mediolani Insubrum. The Reprint of Nallino’s edition: Minerva, Frankfurt, 1969.

  • Neugebauer, O. 1962. Thabit ben Qurra “On the Solar Year” and “On the Motion of the Eighth Sphere. Proceedings of the American Philosophical Society 106: 264–299.

    Google Scholar 

  • Neugebauer, O. 1975. A History of Ancient Mathematical Astronomy. Berlin: Springer.

    Book  MATH  Google Scholar 

  • Newton, R.R. 1973. The Authenticity of Ptolemy’s Parallax Data—Part 1. Quarterly Journal of the Royal Astronomical Society 14: 367–388.

    Google Scholar 

  • Pedersen, O., 1974. A Survey of Almagest. Odense: Odense University Press, 1974. With Annotation and New Commentary by A. Jones, New York: Springer, 2010.

  • Petersen, Viggo M., and Olaf Schmidt. 1968. The Determination of the Longitude of the Apogee of the Orbit of the Sun according to Hipparchus and Ptolemy. Centaurus 12: 73–96.

    Article  MathSciNet  MATH  Google Scholar 

  • Piini, Ernest W. 1986. Ulugh Beg’s Forgotten Observatory. Sky and Telescope 71: 542–544.

    Google Scholar 

  • Qūshčī, ‘Alī b. Muḥammad, Sharḥ-i Zīj-i Ulugh Beg (Commentary on the Zīj of Ulugh Beg), MSS. N: Iran, National Library, no. 20127–5, P: Iran, Parliament Library, no. 6375/1, PN: USA, Rare Book & Manuscript Library of University of Pennsylvania, no. LJS 400.

  • Riccioli, Giovanni Battista, 1665. Astronomia reformata, 2 vols. Bologna.

  • Roberts, Victor. 1957. The Solar and Lunar Theory of Ibn ash-Shāṭir. A Pre-Copernican Copernican Model. Isis 48: 428–432.

    Article  MATH  Google Scholar 

  • Rosenfeld, B.A., İhsanoğlu, E., 2003. Mathematicians, Astronomers, and Other Scholars of Islamic Civilization and Their Works (7th-19th c.), Istanbul: IRCICA.

  • Said, S.S., and F.R. Stephenson. 1995. Precision of Medieval Islamic Measurements of Solar Altitudes and Equinox Times. Journal for the History of Astronomy 26: 117–132.

    Article  MathSciNet  Google Scholar 

  • Saliba, G., 1985. Solar Observations at Maragha observatory. Journal for the History of Astronomy 16: 113–122. Rep. Saliba 1994, 177–186.

  • Saliba, G., 1987. The Role of the Almagest Commentaries in Medieval Arabic Astronomy: A Preliminary Survey of Ṭūsī’s Redaction of Ptolemy’s Almagest. Archives lnternationales d’Histoire des Sciences 37: 3–20. Rep. Saliba 1994, 143–60.

  • Saliba, G. 1994. A History of Arabic Astronomy: Planetary Theories During the Golden Age of Islam. New York: New York University.

    MATH  Google Scholar 

  • Samsó, Julio. 1987. Al-Zarqal, Alfonso X and Peter of Aragon on the Solar Equation. In From Deferent to Equant: A Volume of Studies on the History of Science of the Ancient and Medieval Near East in Honor of E. S. Kennedy, eds. Saliba, G. and King, D. A., vol. 500, 467–476. Annals of the New York Academy of Sciences.

    MATH  Google Scholar 

  • Samsó, Julio. 2011. Las Ciencias de los Antiguos en al-Andalus, 2nd ed. Almería: Fundación Ibn Ṭufayl.

    Google Scholar 

  • Samsó, J., and E. Millás, 1989. Ibn al-Bannā’, Ibn Isḥāq, and Ibn al-Zarqāllu’s Solar Theory. In Islamic Astronomy and Medieval Spain, ed. Samsó, Julio. 1994. . Variorum: Ashgate. Trace X.

  • Sanjufīnī, Sanjufīnī Zīj, MS. Paris: Bibliothèque Nationale, no. Arabe 6040.

  • Seemann, H.J., 1929. Die Instrumente der Sternwarte zu Marāgha nach den Mitteilungen von al-‘Urḍī” in Sitzungsberichte der Physikalisch-medizinischen Sozietät zu Erlangen, ed. Oskar Schulz, vol. 60 (1928), 15–126. Erlangen: Kommissionsverlag von Max Mencke, 1929.

  • Sezgin, F., 1978. Geschichte des arabischen Schrifttums, Band VI: Astronomie bis ca. 430 H. Leiden: Brill.

  • Sezgin, F., and E. Neubauer, 2010. Science and technology in Islam, 5 vols. Frankfurt: Institut für Geschichte der Arabisch–Islamischen Wissenschaften.

  • Shevchenko, M. 1990. An Analysis of Errors in the Star Catalogues of Ptolemy and Ulugh Beg. Journal for the History of Astronomy 21: 187–201.

    Article  MathSciNet  Google Scholar 

  • Simon, J.L., P. Bretagnon, J. Chapront, M. Chapront-Touze, G. Francou, and J. Laskar. 1994. Numerical Expressions for Precession Formulae and Mean Elements for the Moon and the Planets. Astronomy & Astrophysics 282: 663–683.

    Google Scholar 

  • Standish, E.M., 1998. JPL Planetary and Lunar Ephemerides, DE405/LE405. JPL Interoffice Memorandum 312.F-98-048.

  • Swerdlow, N.M. 1972. Al-Battānī’s Determination of the Solar Distance. Centaurus 17: 97–105.

    Article  MathSciNet  MATH  Google Scholar 

  • Swerdlow, N.M. 1973. The Derivation and First Draft of Copernicus’s Planetary Theory: A Translation of the Commentariolus with Commentary. Proceedings of the American Philosophical Society 117: 423–512.

    Google Scholar 

  • Swerdlow, N.M. 1975. On Copernicus’ Theory of Precession. In The Copernican Achievement, ed. R. Westman. Berkeley: University of California Press.

    Google Scholar 

  • Swerdlow, N.M. 2010. Tycho, Longomontanus, and Kepler on Ptolemy’s Solar Observations and Theory, Precession of the Equinoxes, and Obliquity of the Ecliptic. In Ptolemy in perspective (Archimedes, 23), ed. A. Jones, 151–202. Dordrecht: Springer.

    Chapter  Google Scholar 

  • Swerdlow, N.M., and O. Neugebauer. 1984. Mathematical Astronomy in Copernicus’s De Revolutionibus. New York: Springer.

    Book  MATH  Google Scholar 

  • Taqī al-Dīn Muḥammad b. Ma‘rūf, Sidrat muntaha’l-afkar fī malakūt al-falak al-dawwār (The Lotus Tree in the Seventh Heaven of Reflection) or Shāhanshāhiyya Zīj, MSS. K: Istanbul, Kandilli Observatory, no. 208/1 (up to f. 48v; autograph); N: Istanbul, Süleymaniye Library, Nuruosmaniye Collection, no. 2930; V: Istanbul, Süleymaniye Library, Veliyüddin Collection, no. 2308/2 (from f. 10v).

  • Taqī al-Dīn Muḥammad b. Ma‘rūf, Kharīdat al-durar wa jarīdat al-fikar (The non-bored pearls and the arrangement of ideas), MSS. B: Berlin, Staatsbibliothek zu Berlin, no. Ahlwardt 5699 = WE. 193; C1: Cairo, Dār al-Kutub, Ṭal‘at Mīqāt Collection, no. 900; C2: Cairo, Dar al-Kutub, Ṭal‘at Mīqāt Collection, no. 76; E: Istanbul, Süleymaniye, Esad Efendi Collection, no. 1976; K: Kandilli Observatory, no. 183.

  • Thoren, V.E., and J.R. Christianson. 1990. The Lord of Uraniborg: A Biography of Tycho Brahe. Cambridge: Cambridge University Press.

    Google Scholar 

  • Thurston, H. 2002. Greek Mathematical Astronomy Reconsidered. Isis 93: 58–69.

    Article  MathSciNet  MATH  Google Scholar 

  • Toomer, G.J. 1969. The Solar Theory of az-Zarqāl: A History of Errors. Centaurus 14: 306–336.

    Article  MathSciNet  MATH  Google Scholar 

  • Toomer, G.J. 1987. The Solar Theory of Az-Zarqal: An Epilogue. Saliba and King 1987: 513–519.

    MathSciNet  MATH  Google Scholar 

  • Toomer, G.J. (ed.). 1998. Ptolemy’s Almagest. Princeton: Princeton University Press.

    Google Scholar 

  • al-Ṭūsī, Naṣīr al-Dīn, Taḥrīr al-majisṭī (Exposition of the Almagest), MSS. Iran, Parliament Library, P1: no. 3853, P2: no. 6357, P3: no. 6395.

  • Ulugh Beg, Sulṭānī Zīj, MS. P1: Iran, Parliament Library, no. 72; MS. P2: Iran, Parliament Library, no. 6027.

  • Van Helden, A. 1985. Measuring the Universe; Cosmic Distances from Aristarchus to Halley. Chicago: The University of Chicago Press.

    Google Scholar 

  • van Dalen, B., 2002a. Islamic and Chinese Astronomy Under the Mongols: A Little-Known Case of Transmission. In From China to Paris: 2000 years Transmission of Mathematical Ideas, eds. Dold-Samplonius, Y., J.W. Dauben, M. Folkerts, and B. van Dalen, 327–356. Stuttgart: Franz Steiner.

  • van Dalen, B. 2002b. Islamic Astronomical Tables in China: The Sources for the Huihui li. In History of Oriental Astronomy; Proceedings of the Joint Discussion-17 at the 23rd General Assembly of the International Astronomical Union, organised by the Commission 41 (History of Astronomy), held in Kyoto, August 25–26, 1997, ed. Ansari, S.M.R., 2002, 19–30. Dordrecht: Springer.

    Google Scholar 

  • Verbunt, F., and R.H. van Gent. 2012. The Star Catalogues of Ptolemaios and Ulugh Beg; Machine-Readable Versions and Comparison with the Modern HIPPARCOS Catalogue. Astronomy & Astrophysics 544: A31.

    Article  Google Scholar 

  • Wesley, W.G. 1979. Tycho Brahe’s Solar Observations. Journal for the History of astronomy 10: 96–101.

    Article  MathSciNet  Google Scholar 

  • Wilson, Curtis. 1969. The Error in Kepler’s Acronychal Data for Mars. Cantaurus 13: 263–268.

    Article  MATH  Google Scholar 

  • Yabuuti, K. 1987. The Influence of Islamic Astronomy in China. Saliba and King 1987: 547–559.

    MathSciNet  MATH  Google Scholar 

  • Yabuuti, K. 1997. “Islamic Astronomy in China during the Yuan and Ming Dynasties” tr. and Partially Revised by Benno van Dalen. Historia Scientiarum 7: 11–43.

    MathSciNet  MATH  Google Scholar 

  • Yaḥyā b. Abī Manṣūr, Zīj al-mumtaḥan, MS. E: Madrid, Library of Escorial, no. árabe 927, published in The verified astronomical tables for the caliph al-Ma’mūn, Sezgin, F. (ed.) with an introduction by Kennedy E. S., Frankfurt am Main: Institut für Geschichte der Arabisch-Islamischen Wissenschaften, 1986, MS. L: Leipzig, Universitätsbibliothek, no. Vollers 821.

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Acknowledgements

The author extend his sincerest thanks to Benno van Dalen (Germany), Julio Samsó (Spain), and Noel Swerdlow (United States) for their encouragements and kind helps. The solar longitudes in this article have been computed with the aid of van Dalen’s very useful PC program Historical Horoscopes. This work has been financially supported by the Research Institute for Astronomy and Astrophysics of Maragha (RIAAM) under research project No. 1/5440-57.

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Mozaffari, S.M. An analysis of medieval solar theories. Arch. Hist. Exact Sci. 72, 191–243 (2018). https://doi.org/10.1007/s00407-018-0207-1

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