The orientation of the Mithraea in Ostia Antica

We conducted an investigation on the orientations and geometrical content of the Mithraea of Ostia Antica. A geometrical CAD study based on the most reliable plans from the Archives of the Sovrintendenza Speciale per il Colosseo, il MNR e l’Area Archeologica di Roma – Ostia Antica, aside with the identification of geometrical and numerical schemes and associated length units, allowed us to identify the axes of the Mithraea. Then the orientations of the axes were measured on field by means of a professional compass with ± 0.5° uncertainty. The distribution of these measured azimuths follows the topography of the city. On the contrary, the Decumanus, the main street of the town, presents an indubitable orientation toward the Winter Solstice Sunset. This was ascertained by measuring the coordinates of four significant points along the street with the help of a palmar Trimble GPS which averages 100 measures per point. The exceptional density of Mithraea in Ostia led us to suppose that a symbolic cosmic-solar value is to be searched in the orientation as a whole of the town itself, founded half a millennium before the first presence of Mithraism in Rome. The Decumanus could be considered the very holder of this symbolic value with its orientation toward the Winter Solstice Sunset, possibly making of Ostia a very special place for Mithraicism

Wind and nebula of the M33 variable GR290 (WR/LBV)

Context: GR290 (M33/V532=Romano's Star) is a suspected post-LBV star located in M33 galaxy that shows a rare Wolf-Rayet spectrum during its minimum light phase. In spite of many studies, its atmospheric structure, its circumstellar environment and its place in the general context of massive stars evolution is poorly known. Aims: Detailed study of its wind and mass loss, and study of the circumstellar environment associated to the star. Methods: Long-slit spectra of GR290 were obtained during its present minimum luminosity phase with the GTC together with contemporaneous BVRI photometry. The data were compared with non-LTE model atmosphere synthetic spectra computed with CMFGEN and with CLOUDY models for ionized interstellar medium regions. Results: The current $m_V=18.8$ mag, is the faintest at which this source has ever been observed. The non-LTE models indicate effective temperature $T_{eff}$=27-30 kK at radius $R_{2/3}$=27-21 Rsun and mass loss rate $\dot{M}=1.5\times10^{-5}$ Msun yr$^{-1}$. The terminal wind speed $V_\infty$=620 ${\rm km~s^{-1}}$ is faster than ever before recorded while the current luminosity $L_*=(3.1-3.7)\times 10^5$ Lsun is the lowest ever deduced. It is overabundant in He and N and underabundant in C and O. It is surrounded by an unresolved compact HII region with dimensions $\leq$4 pc, from where H-Balmer, HeI lines and [OIII] and [NII] are detected. In addition, we find emission from a more extended interstellar medium (ISM) region which appears to be asymmetric, with a larger extent to the East (16-40 pc) than to the West. Conclusions: In the present long lasting visual minimum, GR290 is in a lower bolometric luminosity state with higher mass loss rate. The nearby nebular emission seems to suggest that the star has undergone significant mass loss over the past $10^4-10^5$ years and is nearing the end stages of its evolution.Comment: submitted to A&A, 12 pages, 9 figures, 7 table

The concept of time, from Palaeolithic to Newtonian physics

The evolution of the concept of time, from the first hunters-gatherers communities of the Paleolithic to the Newtonian physics is shortly reviewed. In particular, attention id paid to the social needs that contributed to change this concept from the Prehistory to the Bronze Age and then to the Iron Age, the classical philosophy, the Middle Ages and the Renaissance, up to the birth of modern science

L’incidenza dei fenomeni astronomici transienti nell’arte del medioevo e del primo rinascimento: forma e colore nella rappresentazione della stella dei magi

Il gruppo di ricerca ha intrapreso da diversi anni uno studio la cui finalità è quella di verificare se fenomeni astronomici transienti particolarmente vistosi (transiti di comete brillanti, esplosioni di supernovae, ecc.) siano da considerarsi quali fonti di ispirazione per opere d’arte medievali nelle quali siano state rappresentate stelle o altri fenomeni celesti. A questo fine, è stato costruito un data-base con cui si sono catalogate le opere d’arte che rappresentano i Magi e la Natività. I nostri primi risultati mostrano effettivamente una forte correlazione statistica tra numerose opere d’arte e questi eventi astronomici particolarmente luminosi ed impressionanti almeno per i secoli XII - XIII e, in parte, per il XIV (Incerti, Bònoli, Polcaro, 2010, 2011, 2014; Polcaro, Bònoli, Incerti, 2011). Il presente lavoro presenta un database implementato anche per il XV secolo e si propone, attraverso l’analisi delle qualità formali e cromatiche delle stelle rappresentate, di valutare l’incidenza degli episodi astronomici straordinari sulla produzione artistica medioevale e del primo Rinascimento

The Star of Magi: transient astronomical events as inspiration sources of Late Medieval art

It is known that a number of exceptional and highly impressive astronomical events have been represented in artworks made in past centuries. However, no systematic survey of figurative Medieval and Renaissance art has been performed to date, in order to analyzing the role of transient astronomical events as inspiration sources of artworks in these epochs. We have thus started to build up a data-base including a significant number of artworks, dated between the 9th and 16th Century and representing figurative elements in some way connected with Astronomy, in order to evaluate if they have been influenced by coeval extraordinary astronomical events. In this work, we analyze a first set of Renaissance artworks. The data base: 193 episodes

The Star of Magi: transient astronomical events as inspiration sources of Late Medieval art

It has long been recognized that a number of exceptional and highly impressive astronomical events are represented in Medieva I artwork, such as the Bayeux Tapestry and Giotto's \u2022Adoration of Magi' in the Scrovegni Chapel in Padua, representing the P/Halley comet transits of 1067 and 130 I, respectively, while it has been suggested that the \u2022Apparition of Star to Magi' fresco in the San Pietro in Valle Abbey in Ferentillo (I 182) represents the I 181 Supernova. To date, however, no systematic survey of figurati ve Medieval and Renaissance art has been carried out in order to analyse the role of transient astronomical events as sources of inspiration in artworks in these epochs. In this work, we analyse more than a hundred artworks-dating between the 12th and 14th centuries-representing figurative elements connected with astronomy. Our statistical analysis reveals that the artists may have been inspired and even influenced by coeval astronomical events, today well known, but extraordinary and impressive to their eyes

Transient astronomical events as inspiration sources of medieval art: III - the 13th and 14th century, and the Case of the French Ordre de l’Étoile

Going ahead in our long term project of analyse the role of transient astronomical events as inspiration sources of Medieval art, we extend our interest towards the 13th and 14th centuries, epochs of strong changes either in society, art and science. It is our aim to verify if the relationship we found in the 11th century between the number of artworks, where a star is represented, and astonishing transient astronomical events was in this new situation still valid. Moreover, in order to check the influence of astronomical events on 14th-century social and cultural environment, we focus on the case of the “Ordre de l’Étoile”, a chivalry society founded by John II of France (Jan le Bon, roi de France) at the end of 1351, looking in ancient chronicles for some relevant contemporary astronomical event as inspiration source for the “star” in the Order name, in the garb of its knights and in its motto

The Gaugamela battle eclipse: An archaeoastronomical analysis

A total lunar eclipse occurred during the night preceding the decisive Battle of Gaugamela (20th September 331 BCE), when the Macedonian army, led by Alexander the Great, finally defeated the Persian king Darius and his army. This astronomical event, well known to historians, had a relevant role on the battle outcome. The eclipse was described in detail by Babylonian astronomers, though, unfortunately, the text of their report has only partially been preserved. We have reconstructed the evolution of the phenomenon as it appeared to the observer in Babylonia, by using the positional astronomy code "Planetario V2.0". On the base of this reconstruction we suggest a number of integrations to the lost part of the text, allowing a finer astrological interpretation of the eclipse and of its influence on the mood of the armies that set against each other on the following morning. Copyright © 2008 MAA

The concept of time, from Palaeolithic to Newtonian physics

The evolution of the concept of time, from the first hunters-gatherers communities of the Paleolithic to the Newtonian physics is shortly reviewed. In particular, attention id paid to the social needs that contributed to change this concept from the Prehistory to the Bronze Age and then to the Iron Age, the classical philosophy, the Middle Ages and the Renaissance, up to the birth of modern science