Colourful Planets

In the Myth of Er, Plato describes the ‘Spindle of Necessity’, a contraption presenting the cosmos as guided by Sirens and Fates, and ascribes different colours to the planets (Rep. 616e-617a). This paper argues that Plato probably used astronomical data for that passage, but possibly gave them a metaphorical sense, and discusses the likelihood of his having used Mesopotamian sources. The second half of the paper studies receptions of and allusions to the image, with context-based astronomical, political, and metaphysical features. Cicero adjusted the image to contemporary astronomy, and to the political function of the cosmic structures in the Somnium Scipionis. His commentator Macrobius emphasizes empirical correctness, but possibly with metaphysical undertones. Apuleius’ Metamorphoses alludes to the image in a portrait of Isis, perhaps to refer to her metaphysical role. Finally, Proclus interprets the Platonic passage as primarily metaphysical, and pointing to truths beyond astronomical phenomena.

A New Demotic Horoscope from Medinet Habu

The relatively small set of Demotic astrological texts from Medinet Habu may be increased by a newly identified horoscope recorded on an ostracon held at the Cairo Museum. Despite the lack of pertinent data in the official records, the origin of this sherd seems to be certain thanks to some telling palaeographical and textual indications. The date recorded on this potsherd indicates the late first century AD and refers explicitly to the Alexandrian calendar. With regard to the content, it preserves the general format and layout of the Demotic horoscopes on ostraca from Medinet Habu, albeit with some small differences in the type and arrangement of the data. This horoscope leaves out some astronomical data common to other Medinet Habu horoscopes which, along with some other Theban horoscopic ostraca, might confirm a trend among Theban astrologers going from more detailed and complicated compositions to less elaborate and more simplified ones.

On the chronology of the Anonymous Commentary to Ptolemy’s Tetrabiblos: Analysis of the astronomical evidence

In this paper, a proposal is made that the Anonymous Commentary to Ptolemy’s Tetrabiblos (Anon. in Ptol.) was composed not before 467 and not after 575 AD. In establishing the terminus post quem and the terminus ante quem, the Author relies on astronomical data provided by the Anonymous himself in his commentary to Ptolemy, Tetrabiblos (=Ptol. Tetr.) II.10 (p. 76, ll. 16-29 Wolf). In this passage, he reports that his master completely succeeded in interpreting the appearance of a celestial beam (δοκός) as a sign of a great loss of trunks, after which a naval battle took place where many ships were sunk; moreover, the master of the anonymous commentator predicted that the comet would remain visible until the end of Mercury’s retrogradation, and so it happened. As will be seen below, it is possible to crosscheck all this data to obtain a precise date of the comet’s appearance: 467 AD, 1 year before the naval battle of Cape Bon (468 AD). These years are also consistent with the dating that can be obtained from one of the horoscopes transmitted by the anonymous commentary (p. 98 Wolf), which corresponds to a birth that actually took place in Lower Egypt on 25 June 448 AD.

Galaxy Morphological Image Classification using ResNet

Machine learning-based techniques are used widely for the classification of images into various categories. The advancement of Convolutional Neural Network (CNN) affects the field of computer vision on a large scale. It has been applied to classify and localize objects in images. Among the fields of applications of CNN, it has been applied to understand huge unstructured astronomical data being collected every second. Galaxies have diverse and complex shapes and their morphology carries fundamental information about the whole universe. Studying these galaxies has been a tremendous task for the researchers around the world. Researchers have already applied some basic CNN models to predict the morphological classes of the galaxies. In this paper, a residual network (ResNet) model is applied for this purpose. The proposed methodology classified the galaxies depending on their shape into 37 different classes. The performance of the methodology was evaluated using the data set provided by Kaggle. In this data set, 61,578 galaxy images are given, which are classified by human eye. The model achieved nearly 98% accuracy.

ITERA Astronomical Observatory Information System

In the current information age, data is a valuable asset for companies [1]. Technological advances encourage the digitization of information in almost all fields of science, including astronomy. Technological developments make it easy to access open data in the public domain. The availability of open data will encourage the acceleration of research. ITERA Astronomical Observatory is an observatory located in Lampung. This observatory is claimed to be the largest in Southeast Asia [3]. To face the challenges in the digitization of information, ITERA Astronomical Observatory plans to build an information system specifically for Storing and handling astronomical data

‘El Capri Kylex’: A Franciscan astronomical mnemonic

This article examines the role of memory techniques in medieval astronomy. Using a mnemonic written by a Franciscan friar c. 1330 as a case study, it shows how astronomers and astrologers simplified the sky for practical purposes, using verses and codes to make their science memorable. The article decodes the mnemonic and its underlying astronomical data, assessing its usefulness, memorability and adaptability alongside some other popular astronomical and calendrical mnemonics of the later Middle Ages. It argues that astronomical learning could be a creative, playful activity. And it situates the astrological practices of this particular friar, who made wide-ranging annotations in a 13th-century astronomical compendium, within the scientific and educational traditions of his order.