Journal for the History of Astronomy

The article explores Johannes Kepler’s abortive attempts to produce an opulent, decorative art object to accompany the publication of his first treatise, Mysterium Cosmographicum (1596). It was Kepler’s hope that this Credentzbecher, so-called because it was designed to resemble a large, ceremonial chalice, would valorize the significance of what he believed to be an epoch-defining discovery concerning the proportional nature of the planetary intervals and serve as a personal introduction to his local sovereign, Duke Friedrich I of Württemberg (1557–1608). The correspondences of Kepler and his circle, some of which have been reproduced and translated here for the first time, reveal in excruciating detail the struggles to negotiate the demands, and exacting standards, of the Stuttgart court and Kepler’s difficulty working with the local goldsmiths employed by the court to enact his vision. Though met with skepticism and destined for failure, the model, its design, and the misunderstandings its failure revealed, poignantly display the sometimes-insurmountable gap between artisanal knowledge and scientific ambition.

A common aspect of the practice-oriented side of pre- and early modern mathematical astronomy was the computation of ephemerides, that is, tables that displayed the daily positions of the planets in a synoptic and calendrical format. Even though medieval Europe was no exception in this regard, the existence of ephemerides in this period and region has gone largely unnoticed, owing both to terminological difficulties and the low survival rate of actual specimens. What exists in significant numbers, however, are texts describing different approaches to constructing ephemerides and computing their various entries. The article demonstrates this by discussing ten such texts dating from approximately the middle of the 12th century to just after 1300. Taken in its entirety, this hitherto neglected corpus provides conclusive evidence against a view according to which ephemerides entered European astronomical practice only in the 15th century.

This article pursues two main goals: (1) to reconstruct the history of the 12 zodiac constellation system in the astronomy of ancient Mesopotamia; (2) to reveal traces of this system directly in cuneiform texts. Among the most important circumstances led to appearance of this system: (1) development of ideas about the band of zodiac constellations, including—according to MUL.APIN—the total of 18 (or 17) constellations; (2) usage of the schematic year, containing 12 months, 30 days each, and (3) development of ideas about mathematical or uniform zodiac, subdivided into 12 equal parts, 30° each. A sequence of the so-called Normal stars singled out in the zodiacal band is an additional important source shedding light on the history of the Mesopotamian zodiac. The designations of Normal stars adopted in Astronomical diaries and other texts indicate that the system of 18 constellations was used in Mesopotamia until the end of cuneiform civilization. This means that in the second half of the first millennium BC the system of 18 constellations, adopted in MUL.APIN, and the system of 12 zodiacal constellations, borrowed from Babylonians by Greek astronomers, were used in parallel. It is also shown in the article that the system of 12 zodiac constellations was used in magical and astrological text BRM 4.20, dated back approximately to the last third of the fourth century BC.

The Lunar Laser Ranging (LLR) has been the main method of study of the dynamics of the Sun-Earth-Moon system since 1969 to present. Lunar parts of the three modern high-precision ephemerides of the Solar system bodies are based solely on LLR measurements: DE (USA), EPM (Russia), INPOP (France). LLR measurements allow to determine parameters of lunar orbital and rotational motion, as well as some parameters related to terrestrial and lunar tides, and also fundamental relativistic parameters. Those parameters were determined from LLR with high accuracy by different authors. In USSR, LLR measurements were performed in the Crimean Astrophysical Observatory (CrAO) in Nauchny, on the 2.6 m Shajn’s Zenith telescope (ZTSh) with an automated laser ranging system developed by the Russian Lebedev Physical Institute (LPI). Within the time span of 1969–1984, 1400 measurements were obtained. Unlike LLR measurements done in other observatories, they were eventually forgotten and have not made their way into the dataset that is used by scientists worldwide to build lunar ephemerides and conduct other lunar research. The main reason for writing this paper was the discovery by Tryapitsyn, a researcher at the Katziveli station of CrAO, of old printouts containing the 1970–1984 LLR observations made with the ZTSh 2.6 m telescope. Some details were missing from the printouts, which required careful restoration work. In this paper the history of those LLR observations with surrounding historical events is presented, and some details of the analysis these observations are described. Of particular interest is the finding related to the three normal points of Lunokhod-1 ranges obtained in 1974 that allowed Odile Calame to determine the rover’s position with a few kilometers accuracy. Unfortunately, the accuracy was not sufficient for other researchers to confirm and pin down the location of the rover.

The historical evidence from the past two millennia show two problems concerning the star Algol (β Per): First, a critical variation in its brightness from a magnitude m ~ 2 in (1) Ptolemy’s Almagest (2nd century AD) and reported by (2) al-Ṣūfī (10th ct.) through its diminution to m = 4 in (3) the star catalog prepared by the Persian astronomers in service of the Yuan dynasty of China in the 13th ct. to becoming brighter, m = 3, as reported by (4) Ibn al-Shāṭir (14th ct.) and (5) Tycho Brahe (16th ct.). In the early modern period, it returned back to m ~ 2, as reported, for example, by Hevelius and Flamsteed (17th ct.), before the discovery of its periodic variability in 1783. Second, al-Ṣūfī reports it as a red star. We present detailed analyses of the sources (3) and (4) for the test of their accuracy and reliability. Our conservative hypothesis concerning the first problem is that the past astronomers observed the star at various phases of its 3-day period of variability. We reject the reddening to have arisen from the extinction due to either the Earth’s atmosphere or an interstellar medium. For resolving both problems, we instead speculate on astrophysical explanations for the observations. These are: copious dust produced as a result of arrested coronal mass ejections or pulverized planetary debris that resides close to the central binary before being dispersed; and a much-enhanced accretion rate that lead Algol into a W Ser-like state in which the primary was enveloped in an inflated accretion disk. We draw an analogy between the dimming of Algol and the recent dimming of Betelgeuse in order to highlight the value of historical observations for understanding astrophysical phenomena.