Starting the Classification: New and Old Stars,and Sometimes Comets,Too

Pigott Edward , “Observations and remarks on those stars which the astronomers of the last century suspected to be changeable”, Philosophical transactions, lxxvi (1786), 189–219.

Zsoldos E. , “Three early variable star catalogues”, Journal for the history of astronomy, xxv (1994), 92–98.

Pigott , op. cit. (ref. 1), 214.

Hoskin Michael , “Goodricke, Pigott and the quest for variable stars”, Journal for the history of astronomy, x (1979), 23–41.

Goodricke John , “A series of observations on, and a discovery of, the period of variation of the light of the bright star in the head of Medusa, called Algol”, Philosophical transactions, lxxiii (1783), 474–82. Although the paper was published under Goodricke's name, Pigott had a substantial part in it, see Hoskin , op. cit. (ref. 4), 26–28.

Although a very long periodicity was hypothesized in the case of Tycho's star (see ref. 24 below), it never re-emerged from invisibility.

Gaab Hans Leich Pierre Löffladt Günter (eds), Johann Christoph Sturm (1635–1703) (Frankfurt am Main, 2004).

First appeared in 1699–1701. I have access only to the reissue of 1702–4. Dr Hilmar Duerbeck, however, kindly checked a copy of the first edition in the Universitäts- und Stadtbibliothek Köln, and found no difference between the two editions. Gaab Hans , “Bibliographie zu Johann Christoph Sturm”, in Gaab (eds), Johann Christoph Sturm (ref. 7), 250–328.

Sturm Johann Christoph , Mathesis juvenilis: Or a course of mathematics for young students, iii (London, 1708), 93–94.

Sturm Johann Christoph , Cometarum natura, motus et origo secundum duas hodie celebriores Joh. Hevelii et P. Petiti celeberrimorum mathematicorum hypotheses ita declarata (Altdorf, 1681).

Sturm , Mathesis juvenilis (ref. 9), 94.

Gemma Cornelius , De natura divinis characterismis , ii (Antwerp, 1575), 125. On Dee, see Camden William , The Historie of the Life and Reigne of the most Renowmed [sic] and Victorious Princesse Elizabeth, Late Queene of England (London, 1630), Book II, 53: “Thomas Digsey, and John Dey, Gentlemen, and Mathematicians amongst us, have learnedly proved by Paralactic Doctrine, that it was in the celestiall, not in the Elementary Region: And they were of opinion that it vanished by little and little in ascending.” According to Stephen Johnston, “Like father, like son? John Dee, Thomas Digges, and the identity of the mathematician”, in Clucas Stephen (ed.), John Dee: Interdisciplinary studies in English Renaisssance thought (Dordrecht, 2006), 65–84, Dee wrote a tract, now lost, on the new star titled “De stella admiranda in Cassiopeiae Asterismo, coelitus demissa ad orbem usque Veneris, iterumque in coeli penetralia perpendiculariter retracta lib. 3”.

Riccioli Giovanni Battista , Almagestum novum, i, Pars posterior (Bologna, 1651), 174. On Riccioli see Dinis Alfredo , “Giovanni Battista Riccioli and the science of his time”, in Feingold Mordechai (ed.), Jesuit science and the Republic of Letters (Cambridge, MA, and London, 2003), 195–224.

Riccioli , op. cit. (ref. 13), 174: “… non fuisse Novas, sed antiquas, perpetuasque latentes tamen in profundissimo aetheris, et ob immensam distantiam inconspicuas; quae postea descensu ad nos evaserint visibiles, et iterum ascensu invisibiles…”.

Boulliau Ismaël , Ad astronomos monita duo (Paris, 1667), 12–14. A review, “Ismaeli Bullialdi Ad Astronomos Monita duo”, Philosophical transactions, i (1667), 1667–83, describes it as follows: “… he proceeds to the investigation of the Causes of the Vicissitudes in the Emersion and Disappearance of this Star, and having discoursed, that the apparent Increase and Decrement of every Lucid Body proceeds either from its changed distance from the Eye of the Observer, or from its various site and position in respect of him, whereby the angle of Vision is changed, or from the increase or diminution of the bulk of the lucid body itself: And having also demonstrated it impossible, that this Star should move in a Circle, or in an Ellipsis, and proved it improbable that it should move in a Strait Line, he concludes, that there can be no other genuin, or at least, no other more probable cause of its Emersion and Occultation, than this, That the bigger part of that round Body is obscure and inconspicuous to us, and its lesser part lucid, the whole Body turning about its own Center, and one Axe, whereby for one determinate spece of time it exhibits its lucid part to the earth, for another, subducts it: It nor being likely, that fires should be kindled in the Body of that Star, and that the matter thereof should at certain times take fire and shine, at other times be extinguisht upon the consumption of that matter.” See Boyer Carl B. , “Boulliau, Ismael”, in Complete dictionary of scientific biography (Detroit, 2008), ii, 348–49.

Sturm , Mathesis juvenilis (ref. 9), 95. The reference to Hevelius is probably Hevelius Johannes , Prodromus cometicus, quo historia cometae anno 1664 exorti (Gdansk, 1665), Figure B facing page 12, which shows the structure Hevelius observed.

For example Busch Georg , Von dem Cometen / welcher in diesem 1572. Jar / in dem Monat Novembris erschinen (Augsburg, 1573); and Die andere Beschreibung von dem Cometen / welcher in dem vergangenem 1572. Jar erschienen / und noch jtziger zeit in diesem 73. Jar / unter den Firmamenten sichtbarlichen vorhanden (Erfurt, 1573). Astrologers also talked about the new star as a comet, for example William Lilly, The worlds catastrophe, or, Europes many mutations untill, 1666 (London, 1647), 11: “… we will first handle the Comet, that appeared Anno 1572…”.

Clarke John , Physical science in the time of Nero, being a translation of the Quaestiones Naturales of Seneca (London, 1910), 277. See also Hellman C. Doris , The comet of 1577: Its place in the history of astronomy (New York, 1944), 25–26.

Argoli Andrea , Pandosion sphaericum , 2nd edn (Padua, 1653), 288: “… primum de Stellis intelligit, postremum de veris Cometis….” See Gingerich Owen : “Argoli, Andrea”, in Complete dictionary of scientific biography (ref. 15), i, 244–5.

Sennert Daniel , Thirteen books of natural philosophy (London, 1661), 66: “Yet that it may appear, that we conceive to be most probable; their opinion seems to us most agreeable to truth, who hold that all Comets have been, and appeared in the Region of Heaven which is above the Moon: And if any man will call them new stars, we shall not oppose him.” See Kangro Hans : “Sennert, Daniel”, in Complete dictionary of scientific biography (ref. 15), xii, 310–13, and Newman William R. : “Sennert, Daniel”, ibid., xxiv, 417–19.

Weidler Friedrich Wilhelm , Institutiones astronomiae (Wittenberg, 1754), 365: “Cometae sunt stellae novae, luce debili et motu proprio praeditae, quae vel coma vestitae, vel sine ea, inopinato nonnunquam in conspectum prodeunt.” On Weidler see Poggendorff J. C. , Biographischliterarisches Handwörterbuch zur Geschichte der exacten Wissenschaften, ii (Leipzig, 1863), 1281.

Kirch Gottfried , “Stellae in Cygno Fixae, alternis temporibus visae et invisae, vicissitudines Lipsiae observatae a Godofredo Kirchio”, Acta eruditorum, vi (1687), 647–8. Though this was written in the third person, it still might be the work of Kirch himself and not of the editor of the Acta. See Laeven Hub , The “Acta Eruditorum” under the editorship of Otto Mencke: The history of an international learned journal between 1682 and 1707 (Amsterdam and Maarssen, 1990). Kirch announced the discovery earlier in his Calendarium christianum, judaicum, et turcicum, but I have had no access to a copy of it. Years later he published another paper on the star, which was usually referred to in the literature: Kirch Gottfried : “De varia apparentia stellae in collo Cygni”, Miscellanea Berolinensia, i (1710), 1710–12. On Kirch see Aufgebauer P. , “Die Astronomenfamilie Kirch”, Sterne, xlvii (1971), 1971–47.

Kirch , op. cit. (ref. 22, 1687), 648: “… annorum inter observationes has trina interstitio fere aequali: De cujus tamen conjecturae veritate, ob phenomenorum priorum observationes non satis certas, ipsiusque revolutionis quantitatem, postera demum aetas judicium est latura.” In Cyprianus Leovitius, De nova stella (Lauingen, 1573), A2v—A3r we find the following: “Historiae perhibent tempore Ottonis primi Imperatoris similem stellam in eodem fere loco Coeli arsisse Anno Domino 945…. Verum multo locupletius testimonium in historiis extat de Anno Domin[i] 1264. Quo stella magna et lucida in parte coeli septentrionali circa sydus Cassiopeae apparuit, carens similiter crinibus, ac destituta motu suo proprio….” This short work affected thinking even in the nineteenth century, see Zsoldos Endre Lévai Zsuzsa : “‘Novae’ over Kiskartal”, Journal for the history of astronomy , xxx (1999), 225–30, and Zsoldos Endre : “Kövesligethy Radó, Jókai Mór és az Androméda-köd”, Aetas, xvii (2002), 2002–11. On Leovitius see Oestmann Günther : “Cyprianus Leovitius, der Astronom und Astrologe Ottheinrichs” in Tagungsband des Symposiums Pfalzgraf Ottheinrich (Regensburg, 2002), 348–359.

Keill John , An introduction to the true astronomy (London, 1721), 57: “It is probable that these two Stars might have been the same with that which was seen by Tycho, and that in about 150 Years the same Star may again make its Appearance.” Pigott, op. cit. (ref. 1), 192: “Several astronomers are of opinion, that it has a periodical return, which Keill and others have conjectured to happen every 150 years. This is also my opinion….” See Hoskin Michael : “Novae and variables from Tycho to Bullialdus”, Sudhoffs Archiv, lxi (1977), 1977–204. On Keill see Kubrin David : “Keill, John”, in Complete dictionary of scientific biography (ref. 15), vii, 275–7.

Gaab Hans : “Zur Biographie von Johann Christoph Sturm (1635–1703)”, in Gaab (eds), Johann Christoph Sturm (ref. 7), 12–85. On Weigel see Schielicke Reinhard Herbst Klaus-Dieter Kratochwil S. (eds), Erhard Weigel — 1625 bis 1699: Barocker Erzvater der deutschen Frühaufklärung (Frankfurt am Main, 1999).

Weigel Erhard , Cosmologia (Jena, 1680), 9–10.

Weigel , op. cit. (ref. 26), 9: “Stellae novae sunt, quae eandem cum fixis toto adparitionis tempore servant distantiam, quaeque adeo primo tantum motu moventur…. Stellis novis annumerari quoddammodo possunt Stellae quasi renovatae s. reciprocae, quae certo tempore comparent, crescunt, decrescunt, evanescunt, iterumque comparent in eodem loco, per vices”.

Zinner Ernst , “Zur Erklärung des Lichtwechsels der verminßten Sterne”, Kleine Veröffentlichungen der Remeis-Sternwarte, no. 7 (1952), 1–35. The light curve is on p. 8, showing a somewhat similar behaviour to that of Mira during the second half of the seventeenth century.

Weigel , op. cit. (ref. 26), 9: “Cometae sunt Stellae temporales, quae diverso adparitionis tempore diversam a fixis exhibent distantiam, quaeque adeo motu non tantum primo, sed et secundo, incedunt…. Cometae Planetis assimilantur, unde etiam Planetarum simii vocantur”.

Gaab , op. cit. (ref. 25), 25.

Methuen Charlotte , Kepler's Tübingen: Stimulus to a theological mathematics (Aldershot, 1998), 107. One can find an example in Melanchthon's preface to Sacrobosco's Sphaera, Philip Melanchthon, “Preface to On the Sphere (1531)”, in Melanchthon Philip , Orations in philosophy and education, ed. by Kusukawa Sachiko , transl. by Salazar Christine F. (Cambridge, 1999), 105–12.

Quenstedt Johann Andreas , Theologia didactico-polemica (Wittenberg, 1691), 535. “Distinguitur (2.) Providentia in extra-ordinariam et ordinariam. Extraordinaria est, quando Deus vel absque mediis vel praeter aut supra media, vel contra media eorumque naturam, sive quod idem est, supra et contra ordinem a se institutum operatur…. Ordinaria est, qua Deus per media ordinaria videl. per institutum et consuetum naturae cursum opera sua exequitur.” The translation is from Schmid Heinrich , The doctrinal theology of the Evangelical Lutheran Church, transl. by Hay Charles A. Jacobs Henry A. (Philadelphia, 1899), 193. For a recent discussion of the question of extraordinary providence see Wood Charles M. , “How does God act?”, International journal of systematic theology, i (1999), 1999–52. See also Methuen Charlotte , “Special providence and sixteenth-century astronomical observations: Some preliminary reflections”, Early science and medicine, iv (1999), 1999–113. Methuen considers the sixteenth century when Aristotle's theory of comet generation was still thought valid. It was not accepted in Wittenberg in the second half of the seventeenth century. On Quenstedt see Wagenmann Julius August , “Johann Andreas Quenstedt”, Allgemeine Deutsche Biographie, xxvii (Leipzig, 1888), 35–37.

For example, Pomarius Samuel , Collegii synoptici in partem generalem physicae disputationem (Wittenberg, 1659), 23: “In extraordinariis Deus sine Natura agit; in ordinariis nec Natura sine Deo, nec deus sine Natura.” Frentzelius Simon Fridericus , Praelucente stella ex Jacob, stellam nati Jesuli a magis visam (Wittenberg, 1661), Bv: “In ordinariis quidem naturalibus Deus sine natura facile non agit…. Extraordinaria vero quae sunt, et inusitata plane, solus plerumque sibi reservavit Deus…”.

Keckermann Bartholomaeus , Systema physicum (Hanau, 1612), 618: “Sunt autem Meteora vel ordinaria, vel extraordinaria, vel mixta.” On p. 679: “Distingui potest duratio cometae in ordinariam et extraordinariam.” Andreas Libavius, Singularium, pars secunda (Frankfurt, 1599). On p. 35 one can find “Mundo coaevum sydus, et stella ordinata …”, while on p. 45: “… recentiores affirmant, esse stellas secundas inordinatas, non aeternas.” This chapter deals with comets, Tycho's star is considered as one itself. Rudolph Goclenius, Idea philosophiae Platonicae (Marburg, 1612), 313: “… distinguunt stellas in ordinatas et aeternas, et inordinatas seu temporaries….” On Keckermann and Goclenius see Freedman Joseph S. , “The career and writings of Bartholomew Keckermann (d. 1609)”, Proceedings of the American Philosophical Society, clxi (1997), 1997–64; Freedman Joseph S. , “‘Professionalization’ and ‘Confessionalization’: The place of physics, philosophy, and arts instruction at central European academic institutions during the Reformation era”, Early science and medicine, vi (2001), 2001–52. On Libavius see Debus Allen G. , The Chemical Philosophy (New York, 2002), 169–73.

Nottnagel Christoph , Synopsis mathematica, editio secunda (Wittenberg, 1657), 157–61. On Nottnagel see Poggendorf , op. cit. (ref. 21), 302–3.

Burgersdijk Franco , De stellis ordinariis et extraordinariis (Leiden, 1631), L4r; Spole Andreas , De stellis fixis (Uppsala, 1683), 44.

The best source for Schnitzler's life is still Seivert Johann , Nachrichten von Siebenürgen Gelehrten und ihren Schriften (Pressburg, 1785), 376–87. See also Zsoldos Endre Blaga Cristina , “Jacob Schnitzler Wittenbergben”, Magyar Könyvszemle, cxxii (2006), 2006–31.

Schnitzler Jacob , De stellis fixis (Wittenberg, 1659), A2r: “Stellae fixae (alias Inerrantes dictae) sunt stellae luce, quantitate egregia et figura quam proxime globosa praeditae, in octavo coeli orbe seu regione perpetuo mobiles, situmque et ordinem eundem, eandemque ad se invicem distantiam et habitudinem retinentes.” This is a version of the usual Wittenberg definition of stars. Some examples: Johannes Sperling, Institutiones physicae (Wittenberg, 1639), 489: “Stellae sunt corpora naturalia simplicia, lucida, globosa, semper mobilia, ex luce primigenia ad salutem inferiorum producta.” Nottnagel, op. cit. (ref. 35), 157: “Stellae sunt corpora simplicia, lucida, quam proxime globosa, ac perpetuo in orbem mobilia, suamque periodum finito temporis spatio absolventia….” Georg Caspar Kirchmaier, De stellis, generaliter spectatis (Wittenberg, 1659), A2r: “Stellae sunt Corpora Naturalia simplicia, lucida, quam proxime globosa, semper mobilia, influentiis admirandis praedita, ex luce primigenia, a Creatore Deo, ad salutem inferiorum producta”.

Schnitzler Jacob , De stellis fixis novis (Wittenberg, 1659), A2r–A2v: “Stellae Fixae Novae sunt Stellae a Deo immediate virtute supernaturali ex nihilo creatae, motum cum reliquis stellis fixis communem habentes et in octavo coeli ad tempus locatae, ut gloriam Dei enarrent….” The definition of comets is very similar, Schnitzler Jacob , De stellis erraticis extraordinariis seu cometis (Wittenberg, 1659), A2r—A2v: “Cometae sunt Stellae erraticae extraordinariae, modo extraordinario a Deo productae, locumque suum in sede Planetarum subter regionem fixarum ad certum tempus obtinentes.” This was, naturally, not a new concept. One can find similar definitions ever since the appearance of Tycho's star. It can even be argued that it originated with Saint John of Damascus, who said about comets in De fide orthodoxa: “they are not of the number of the stars which have existed from the beginning, but by the divine command they take form at just the right time and then are dissolved again.” See Saint John of Damascus, Writings (New York, 1958), 219.

“Stella est densior pars sui orbis”, the usual definition of a star in the late Middle Ages, ascribed erroneously to Aristotle. See the discussion in Grant Edward , Planets, stars, & orbs: The medieval cosmos, 1200–1687 (Cambridge, 1996), 426–8.

Schnitzler Jacob , Comet-Stern predigt (Hermannstadt, 1681), A3v–A4v: “Considerantur stellae fixae vel absolute, vel relative. Absolute consideratae sunt vel ordinariae vel extraordinariae. Ordinariae sunt, quae ab initio mundi semper conspicuae et adhuc conspiciuntur. Extraordinariae, quae singulari Dei dispensatione ad certum tantum tempus conspiciuntur”.

Schnitzler , Comet-Stern predigt (ref. 41), A3v–A4v: “Sind demnach wie gesagt / zweyerley Sterne / Fixae et Erraticae dass ist / stillstehende und hinn- und her-lauffende Sterne / welche sonst auch desswegen Errones genennet werden: Nun gehören solche ungewöhnliche Comet-Stern unter solche hinn und her lauffende Stern, doch aber nicht hiebon Ordinario modo gewöhnlicher weise / wie von andern zu urtheilen: Desswegen heissen sie auch Stellae Erraticae Extraordinariae…. Was ist nun aber eigentlich ein Comet? Ein Comet ist ein seltsamer und ungewöhnlicher Stern / welchen Gott der Herr selbst schaffet / und in die Höhe über uns stellet / hiedurch seine grosse Straff / die Er bey sich beschlossen / über die grosse Sünden der Menschen lassen zu ergehen / anzuzeigen.” The last part of the quote shows that it was indeed intended to be a sermon.

Ibid., Bv: “Aber mann muss hie distingvieren inter opera Dei ordinaria et extraordinaria, einen unterscheid machen zwischen ordentlichen und ausserordentlichen oder sonderlichen Wercken Gottes”.

Szentiványi Márton , Curiosiora et selectiora variarum scientiarum miscellanea (Nagyszombat, 1689), 69: “Novas Stellas generari ex Solis, aliorumque Syderum exhalationibus, et effluvijs. Haec enim effluvia, ubi condensata, et a Sole illuminata fuerint, speciem novarum stellarum referunt.” A similar explanation was considered earlier by Kircher Athanasius , Itinerarium exstaticum (Rome, 1656), 278–9, and Fromondus Libertus , Meteorologicorum (Antwerp, 1627), 124.

Burgersdijk , op. cit. (ref. 36), L4v: “Duobus modis videntur novae stellae fieri posse, nempe condensatione coelestis substantiae, quae fuerat rara, et congressu multorum Planetarum, qui seorsim invisibiles sunt.” Burgersdijk explains the appearance of comets with the first case, of the stars with the second.

Halley Edmond , “A short History of the several New-Stars that have appear'd within these 150 Years; with an Account of the Return of that in Collo Cygni, and of its Continuance observed this Year 1715”, Philosophical transactions, xxix (1715), 354–6.

Keill , op. cit. (ref. 24), 55–56: “Several Stars which were observed by the Antients, are now no more to be seen, but are destroyed, and we have known some new ones come in the Heavens unknown to them; which likewise in due time will vanish, and disappear. There are also some Stars which for a Time are extinguished, and become invisible, but after a certain Period they reassume their former Lustre…. Moreover we are assured from the Observations of Astronomers, that some Stars have been observed which never were before, and for a certain time they have distinguished them by their superlative Lustre; but afterwards decreasing, they by degrees vanished and were no more to be seen.” The text had not changed in the third edition (London, 1739).

Keill , op. cit. (ref. 24), 56: “It is probable that the greatest part Part of the Surface of this Star [i.e. Mira Ceti] is covered with Spots and Dark Bodies, some Part thereof remaining lucid; and while it turns around its Axis, does sometimes show its bright Part, sometimes it turns its dark side to us. But the very Spots themselves of this Star are liable to Changes, for it does not every Year appear with the same Lustre; sometimes it resembles a Star of the second Magnitude; in other Years it can scarcely be reckoned among Stars of the third Order; nor are the Times of its visiting us, always of the same duration; for in some Years after three Months it takes its leave of us, in others we enjoy its Light for the space of four Months; nor does its increase or decrease always answer the difference of Times”.

Zsoldos E. , “The beginnings of variable star astronomy in Hungary”, in Balázs Lajos G. Brosche Peter Duerbeck Hilmar W. Zsoldos Endre (eds), The European scientist: Symposium on the era and work of Franz Xaver von Zach (1754–1832) (Frankfurt am Main, 2004), 132–55.

Pigott , op. cit. (ref. 1).

This is an interesting echo of the Middle Ages as it is clearly “mythologically speaking” about variables. It seems to have been introduced by William of Conches in the twelfth century, when he remarked that “authors deal with celestial matters in three ways: Namely, in terms of myths [fabulose], astrology, or astronomy.” William of Conches, A dialogue on natural philosophy (Notre Dame, 1997), 41. It can be found in the earlier Philosophia (Philosophiarum et astronomicarum (Basel, 1531), 30; published under the name of William of Hirsau) and Glosae super Boetium (Turnhout, 1999), 53, too. Riccioli's list of variables also nicely fits this threefold division, see Zsoldos , op. cit. (ref. 49), 135 and 138–9.

Ferguson James , Astronomy explained upon Sir Isaac Newton's Principles , 2nd edn (London, 1757), 236–7: “It would seem that the periodical Stars have vast clusters of dark spots, and very slow rotations on their Axis; by which means, they must disappear when the side covered with spots is turned towards us. And as for those which break out all of a sudden with such lustre, 'tis by no means improable that they are Suns whose Fuel is almost spent, and again supplied by some of their Comets falling upon them, and occasioning an uncommon blaze and splendor for some time: Which indeed appears to be the greatest use of the cometary part of any system.” The first edition of 1756 did not contain the chapter on the fixed stars. The tenth edition of 1799 has the same text. On Ferguson see Henderson E. , Life of James Ferguson, F.R.S., in a brief autobiographical account. And further extended memoir (Edinburgh, London and Glasgow, 1867). Newton's explanation can be found in Isaac Newton, Philosophiae naturalis principia mathematica, 2nd edn (Cambridge, 1713), 481: “Sic etiam Stellae fixae quae paulatim expirant in lucem et vapores, Cometis in ipsas incidentibus refici possunt, et novo alimento accensae pro Stellis Novis haberi.” Maupertuis's idea appeared in Discours sur les différentes figures des astres (Paris, 1732), 77–78; English translation, Dissertation on the different figures of the coelestial bodies (London, 1734), 62–63.

Weidler , op. cit. (ref. 21), 357–65.

Ibid., 357: “Observationes fixarum, olim cognitarum, hodie inconspicuarum.” The lost Pleiad is once again a case of “mythologically speaking”, see ref. 51.

Weidler , op. cit. (ref. 21), 359: “Observationes stellarum novarum, olim incognitarum, quae rursus evanuerunt, et nondum redierunt.” The new star seen by Haly is the supernova of 1006, see Goldstein Bernard R. , “Evidence for a supernova of A.D. 1006”, Astronomical journal, lxx (1965), 105–14. Weidler took the reference from Cassini Jacques , Éléments d'astronomie (Paris, 1740), 59. It was known in Europe in the Middle Ages, too, see the anonymous tract on the comet of 1238, printed in Thorndike Lynn , Latin treatises on comets between 1238 and 1368 A.D. (Chicago, 1950), 9–61, see pp. 60–61. Thorndike identifies it with the comet of 1006 described in Pingré Alexandre Guy , Cométographie, i (Paris, 1783), 363–5, which, in turn, is identical with Goldstein's supernova of 1006. The supposed new star seen by Albumasar was a comet, see Thorndike , op. cit., 59, and Lynn Thorndike, “Albumasar in Sadan”, Isis, xlv (1954), 1954–32.

Weidler, op. cit. (ref. 21), 360: “Observationes stellarum novarum, olim incognitarum, quae adhuc conspicuae sunt.” For the catalogue variables see Zsoldos , op. cit. (ref. 49).

Weidler , op. cit. (ref. 21), 361: “Observationes stellarum novarum mutabilium, quae per vices recurrunt”.

Herbst Klaus-Dieter , “Der Beitrag von Johann Christoph Sturm zur astronomischen Forschung”, in Gaab (eds), Johann Christoph Sturm (ref. 7), 203–25.