Linee introduttive a Barhadbeshabba di Halwan, Causa della fondazione delle scuole. Filosofia e storia della filosofia greca e cristiana in Barhadbeshabba

Il presente articolo costituisce un’introduzione alla Causa della fondazione delle scuole, una particolare ‘storia della filosofia’ dovuta a Bahadbeshabba, autore nestoriano della Scuola di Nisibi, vissuto nel tardo VI secolo. Sono esaminate la figura storica di Barhadbeshabba e l’opera nei suoi principali punti.The present article is an introduction to the Cause of the Foundation of the Schools, a sort of ‘history of philosophy’ by Barhadbeshabba, a Nestorian author of the School of Nisibis, who lived in the late 6th century. The attention is focused on the historical figure of Barhadbeshabba and on the work in its main points

Helium Emissions Observed in Ground-Based Spectra of Solar Prominences

The only prominent line of singly ionized helium in the visible spectral range, helium-II 4686 A, is observed together with the helium-I 5015 A singlet and the helium-I 4471 A triplet line in solar prominences. The sodium emission, NaD2, is used as a tracer for helium-II emissions which are sufficiently bright to exceed the noise level near 10^-6 of the disk-center intensity. The so selected prominences are characterized by small non-thermal line broadening and almost absent velocity shifts, yielding narrow line profiles without wiggles. The reduced widths [Delta(lambda_D) / lambda] of helium-II 4686 A are 1.5 times broader than those of helium-I 4471 A triplet and 1.65 times broader than those of helium-I 5015 A singlet. This indicates that the helium lines originate in a prominence--corona transition region with outwards increasing temperature.Comment: 12 pages, 5 figure, 3 table

Osservazioni sul concetto di "Giorno Natalizio" nel mondo greco e romano e sull'espressione di Seneca dies aeterni natalis

The article begins with an excursus on the concept of "birthday" in the graeco-roman pagan world and on the celebrations of this day. The second point is an analysis of rlμhpa yEvÉOXios- dies natalis - in early Christian literature, where it often means the day of death and presents an inversion of significance if compared with the current pagan use. Finally, the authoress deals with the Senecan expression dies aeterni natalis (Ep. CII 26), which is referred not to the birthday, but to the day of death.Este artículo comienza con un paréntesis en el concepto de ‘’cumpleaños’’ en el mundo greco-romano pagano y en las celebraciones de este día. El segundo punto es un análisis de rlμhpa yEvÉOXios- dies natalis – en la literatura cristiana temprana, donde a menudo significa el día de la muerte y presenta una inversión del significado si se compara con el actual uso pagano. Finalmente, la autora lidia con la expresión de Séneca dies aeterni natalis (Ep. CII 26), que se refiere no solo al cumpleaños sino también al día de la muerte

Calibration of the 6302/6301 Stokes V line ratio in terms of the 5250/5247 ratio

Four decades ago the Stokes V line ratio in the Fe I 5247.06 and 5250.22 {\AA} lines was introduced as a powerful means of exploring the intrinsic field strengths at sub-pixel scales, which led to the discovery that most of the photospheric flux is in intermittent kG form. The "green" 5247-5250 line pair is unique because it allows the magnetic-field effects to be isolated from the thermodynamic effects. No other line pair with this property has since been identified. In recent years much of the magnetic-field diagnostics has been based on the "red" Fe I 6301.5 and 6302.5 {\AA} line pair, since it was chosen in the design of the Hinode space observatory. Although thermodynamic effects severely contaminate the magnetic-field signatures for this line ratio, it is still possible to use it to extract information on intrinsic magnetic fields, but only after it has been "renormalized", since otherwise it produces fictitious, superstrong fields everywhere. In the present work we explore the joint behavior of these two line ratios to determine how the "contaminated" red line ratio can be translated into the corresponding green line ratio, which then allows for a direct interpretation in terms of intrinsic magnetic fields. Our observations are mainly based on recordings with the ZIMPOL-3 spectro-polarimeter at IRSOL in Locarno, Switzerland, complemented by data from the STOP telescope at the Sayan solar observatory (Irkutsk, Russia). The IRSOL observations are unique by allowing both the green and red line pairs to be recorded simultaneously on the same CCD sensor. We show how the line ratios depend on both the measured flux densities and on the heliocentric distance (the \mu\ value on the solar disk), and finally derive the calibration function that enables the red line ratio to be translated to the green ratio for each \mu\ value

Anneo Cornuto e gli Stoici romani

The article offers an analysis of Annaeus Cornutus’ rich intellectual character in the context of the Roman Stoicism of the Neronian age. The topics explored are: his life the sources, his various fields of research (as in the Stoic tradition of Chrysippus, whom he knew well and Crates of Mallus), his influence on Persius, his relations with Nero Seneca and the Stoics of that time. A brief bibliographical appendix concludes the article