Seminario in modalita` ibrida
link Google meet https://meet.google.com/sxz-cctp-tsc
Speaker: Giacomo Permunian (Universita` di Ferrara)
Titolo : La chimica e mineralogia della condrite ordinaria 6A.
Abstract: Ordinary chondrites (OCs), costituiscono la classe di meteoriti più abbondante tra quelle viste cadere (falls) e trovate (finds). Sulla base delle loro differenze chimiche, isotopiche, mineralogiche e tessiturali (petrografiche) sono suddivise in tre gruppi (H, L, LL). La possibilità di studiare questi materiali con sempre più dettaglio ha permesso di ampliare la nostra conoscenza sulla varietà dei materiali nel Sistema Solare e di comprendere meglio le condizioni chimico-fisiche della nebulosa solare.
Presenterò lo studio in corso della meteorite COs 6A, di tipo H, trovata nella provincia di Tata in Marocco, di cui ho studiato principalmente la petrografia (tessitura della roccia) e la composizione mineralogica dei principali costituenti (olivina, Ca-poor pyroxenes e feldspati). Olivine e pirosseni sono i fondamentali costituenti anche del mantello terrestre (e suoi analoghi del sistema solare), e sono tra i costituenti più comuni delle polveri del mezzo inter e circumstellare. Nell’ambito del tirocinio presso l’INAF di Palermo abbiamo usato questi materiali come analoghi di polvere inter e circumstellare.
Seminario in forma ibrida,
indirizzo Google meet: https://meet.google.com/sxz-cctp-tsc
Speaker: Salvatore Sciortino (INAF)
Titolo: The Athena predicted PSF and ELSP and their effects on X-ray (stellar) studies
In the past 12-18 months improved descriptions of the predicted Athena PSF
(Point Spread Function) and of the predicted Athena/XIFU ELSF (Extended Line
Spread Function) have become available and their effects has been investigated by more detailed simulations of WFI and XIFU based studies. I will discuss and illustrate the most relevant outcomes of this investigations and their possible effect on (stellar) X-ray studies and more in general the currently predicted
capability (and related limit) of future Athena observations.
Speaker: Víctor Almendros Abad (CENTRA, Faculdade de Ciências da Universidade de Lisboa; European Southern Observatory)
Title: Milky Way’s young substellar population
indirizzo google meet: https://meet.google.com/sxz-cctp-tsc
Young clusters and star forming regions are home to a large number of substellar objects with masses below the hydrogen-burning limit at ~0.075 MSun. Most of our knowledge about their populations comes from nearby regions (d < 400 pc), where we find consistent formation rates of 2-5 young brown dwarfs per 10 newborn stars. Brown dwarf theories, on the other hand, predict that high gas or stellar densities, as well as the presence of massive OB stars, may be factors that boost the incidence of newly formed brown dwarfs with respect to stars. The next frontier in substellar studies, therefore, is the exploration of massive star clusters, characterized by significantly different star-forming environments than those found in our immediate vicinity. In this contribution I will present our deep NIR imaging using the AO-supported instrument HAWK-I/VLT in Galactic massive clusters RCW 38 and NGC 2244, complemented by the spectroscopic follow-up using KMOS/VLT. We report the most complete substellar IMFs in the two clusters, along with the first bona-fide brown dwarfs beyond 1 kpc, providing an ideal dataset for a comparison with nearby star forming regions. Finally, I will present our future plans with two approved JWST programs, which include the first substellar IMF in a starburst cluster, and spectroscopic confirmation of first single Jupiter-mass objects in a nearby star forming region.
SPEAKER: Julien Gressot, Doctorant FNS – Histoire des techniques et de l’innovation, Institut d’histoire
AFFILIATION: Université de Neuchâtel (Switzerland)
TITLE: The Photographic Zenith tube (PZT) of the Neuchâtel Observatory: Achievement of time determination or failure of innovation?
ABSTRACT: Throughout its existence, the Neuchâtel Observatory has sought to be at the forefront of astronomical time determination. In the mid-20th century, a technological innovation began to spread in observatories with PZTs (Photographic Zenith Tube). The Neuchâtel Observatory was one of the first to obtain this instrument, the purpose of which was to eliminate the human factor by automating the time determination and certain other instrumental errors. PZTs were presented as the most accurate instruments of their time, but their development was soon halted. In this paper, we will examine the technical evolution of PZTs, the reasons why they became the must-have instrument, and the explanations for their rapid abandonment.
Google Meet room: https://meet.google.com/sxz-cctp-tsc