Elenco dei seminari passati

Visita delegazione di Imam per l’osservazione dell’Hilal

Date: Tuesday 17 Feb 2026

Seminario: Stefano Sandrelli (IAU, INAF)

Date: Tuesday 10 Feb 2026

Titolo: L’Office of Astronomy for Education Center Italy: che cosa è, che cosa fa e perché lo fa in quel modo.

Abstract: Fondato nel marzo 2021, l’Office of Astronomy for Education Center Italy (I-OAE) è un ufficio internazionale della IAU, coordinato e finanziato da INAF. I-OAE promuove e sostiene pratiche di insegnamento innovativo, centrato sulla persona, e di corsi di formazione docenti.

Nei suoi primi anni di esistenza, I-OAE ha sviluppato processi collaborativi, a cui hanno partecipato rappresentanti di Albania, Cipro, Croazia, Egitto, Francia, Grecia, Israele, Italia, Marocco, Montenegro, Palestina, Portogallo, Slovenia, Siria, Spagna e Turchia. Non solo il network è costante crescita, ma si sta dimostrando anche di attrarre fondi europei.

I-OAE coordina anche l’edizione internazionale di astroEDU, la piattaforma di attività didattiche peer-reviewed della IAU.

I-OAE è un ufficio aperto alla collaborazione di volontari che ne condividano valori e metodi.

Seminario: Ileana Chinnici (INAF-OAPa)

Date: Thursday 05 Feb 2026

Title: La complessa vicenda della scoperta di Cerere

Abstract: In questo seminario saranno illustrati i complessi intrecci che si accompagnarono alla scoperta del primo asteroide (ora pianeta nano), Cerere, avvenuta nel 1801 presso l’Osservatorio di Palermo ad opera di Giuseppe Piazzi e dei suoi collaboratori. L’intricata vicenda vide coinvolta l’intera comunità astronomica internazionale ed ebbe risvolti importanti dal punto di vista scientifico, come vedremo. Da questa storia si possono trarre numerose conclusioni di grande attualità: ci soffermeremo su quelle più significative.

Seminario: Alberto Traina (INAF-OAS Bologna)

Date: Thursday 18 Dec 2025

Speaker: Alberto Traina (INAF-OAS Bologna)

Title: SMBHs growth in overdense environments: AGN enhancement in protoclusters with enormous Ly⍺ nebulae

Abstract: SMBHs are almost ubiquitous in galaxies’ nuclei in the local and in the high-redshift Universe. However, the formation and growth processes that lead to such massive objects in relatively short timescales are still unclear. A crucial role in accelerating their evolution may be played by the surrounding environment: large quantities of gas and higher merger rates are key to understand how their growth occurs. Protoclusters of galaxies, the precursors of today’s galaxy clusters, represent the perfect laboratories to investigate this effect at high redshift. The hunt for the SMBHs population in protoclusters and its characterization requires a multi-wavelength effort to obtain a complete census: in this perspective the X-rays represent the best channel to investigate the AGN activity, even in the most obscured conditions. In this talk, I will present recent deep (>200ks) Chandra observations targeting three protoclusters at z ~ 2-3, that host enormous Ly⍺ nebulae. I will discuss the spectral properties of the detected AGN as well as the effects of overdense environment on the growth of SMBHs. In particular, I will show the fraction of AGN and the X-ray luminosity functions of the protoclusters, which are significantly larger (1 – 2 dex!) than those of their local counterparts. I will present new results on how the enhancement of SMBHs in overdense environments (x10 larger than SMGs) suggests that protoclusters are indeed optimal sites for promoting their growth. Finally, I will show preliminary results on the growth of SMBHs in hydrodynamical cosmological simulations.

Seminario: Marco Tarantino (UniPa)

Date: Wednesday 17 Dec 2025

Titolo: Using a Neural Network approach and Starspots dependent models to predict Effective Temperatures and Ages of young stars

Abstract:

This study presents a statistical approach to accurately predict the effective temper-

atures of pre-main sequence stars, which are necessary for determining stellar ages

using the isochrone methodology and cutting-age starspots-dependent models. By

training a Neural Network model on high-quality spectroscopic temperatures from

the Gaia-ESO Survey as the response variable, and using photometric data from

Gaia DR3 and 2MASS catalogs as explanatory variables, we implemented a method-

ology to accurately derive the effective temperatures of much larger populations of

stars for which only photometric data are available. The model demonstrated robust

performance for low-mass stars with temperatures below 7 000 K, including young

stars, the primary focus of this work. Predicted temperatures were employed to con-

struct Hertzsprung-Russell diagrams and to predict stellar ages of different young

clusters and star forming regions through isochrone interpolation, achieving excellent

agreement with spectroscopic-based ages and literature values derived from model-

independent methods like lithium equivalent widths. The inclusion of starspot evolu-

tionary models improved the age predictions, providing a more accurate description

of stellar properties. Additionally, by applying this temperature–age framework to

a large, spatially complete sample of young stars in the solar neighbourhood, we in-

vestigate the recent star formation and how it relates to the structure of the Local

Bubble, thereby describing its role in influencing the local star-formation history.

Presentazione Risultati ExoSchool II

Date: Friday 12 Dec 2025

Seminario: Maria Luisa Tuscano (INAF-OAPa)

Date: Thursday 13 Nov 2025

Title: Piazzi e la Meridiana della Cattedrale di Palermo

Abstract: La realizzazione della meridiana a camera oscura nella Cattedrale di Palermo costituisce una
testimonianza dell’impegno assunto da Giuseppe Piazzi non solo nel quadro di potenziamento dello
studio dell’Astronomia, ma anche verso iniziative sociali volte al benessere del territorio e
all’affermazione di Palermo nel contesto internazionale.
Gli anni trascorsi a Londra avevano fatto apprezzare all’astronomo l’adozione del Tempo medio
nell’ambito dello sviluppo economico legato alla prima rivoluzione industriale.
La riforma della misura del Tempo nella città di Palermo costituì per Piazzi un obiettivo sociale da
raggiungere attraverso un graduale processo educativo del territorio, in cui era ancora in uso l’orario
italico civile.
La meridiana, misurando il tempo astronomico, costituiva l’anello di congiunzione per la successiva
introduzione del tempo medio
Ma l’individuazione di Cerere limitò in parte il piano di Piazzi che, comunque ci lascia uno strumento
molto apprezzato a livello mondiale e di cui si auspica un’adeguata preservazione per il suo peculiare
valore scientifico e didattico.

Seminario: Elina Lindfors (University of Turku)

Date: Tuesday 11 Nov 2025

Titolo: Association of the astrophysical neutrinos with flares from relativistic jets launched by supermassive black holes?

Abstract:

Over the past decade, the IceCube Neutrino Observatory has detected a few hundreds of high-energy (HE) neutrinos from cosmic sources. Despite numerous studies searching for their origin, it is still not known which source populations emit them. A few confident individual associations exist with active galactic nuclei (AGN), mostly with blazars which are jetted AGN whose jet points in our direction. Nonetheless, on a population level, blazar-neutrino correlation strengths are rather weak. To definitively answer if jetted AGN systematically emit >~100 TeV neutrinos: (1) we compiled the largest catalog of blazars and their optical light curves to date; and (2) we searched for a spatio-temporal correlation between these blazar light curves and IceCube’s first catalog of >~100 TeV neutrino events while assuming that neutrinos are expected at the brightest optical outbursts. Under this phenomenological assumption, we found that a global blazar-neutrino correlation cannot be confidently established, inline with the result of our previous study in the radio band. We estimated that fewer than ~8% of >~100TeV neutrino events came from major blazar outbursts, alluding to substantial contributions from other systems. In my talk, I will present this state-of-the-art correlation study and outlook for further searches with next generation of instruments.

Seminario: Maria Messineo (UniBo)

Date: Thursday 06 Nov 2025

Titolo: Bright late-type stars in the thin Disk of the Milky Way

Abstract: Red supergiants (RSGs) and asymptotic giant branch (AGB) stars are the
brightest sources at infrared wavelengths, detectable at a distance
of a few megaparsecs —- even in heavily obscured galactic centers.
Through winds and mass loss, they enrich and sculpt the interstellar
medium.
Despite similar spectral energy distributions and apparent magnitudes,
RSGs and AGBs trace distinct spatial structures of a galaxy.
AGBs trace well the gravitational potential, including the central bar,
and span ages from 50 Myr to a Hubble time. RSGs, aged 4.5–40 Myr, decorate
the spiral arms, the central molecular disk, and the bar’s endpoints.
The Milky Way offers the nearest laboratory for resolved stellar
populations
in a barred galaxy, however, dust obscuration and distance uncertainties
hinder
clean separation of RSGs and AGBs -— a critical step for mapping Disk
structure
and star-formation history.
Over the past several years, I have developed methods to estimate
extinction
by partitioning interstellar and circumstellar components, to obtain better
luminosity and to distinguish RSGs from AGBs. I will highlight key
challenges
and solutions, including extinction-free colors as interstellar
extinction proxies,
GLIMPSE color–color diagrams, and Gaia–2MASS criteria.
Finally, I will present a new Gaia catalog of ~700 bona fide optical RSGs,
detailing its construction, temperature, and luminosity characterization.

Seminario: Ileana Chinnici (INAF-OAPa)

Date: Thursday 23 Oct 2025

Titolo: “Da Piazzi in poi: oltre duecento anni di attività dell’Osservatorio Astronomico di Palermo”

Abstract: Saranno esaminati i principali contributi scientifici dati dall’Osservatorio di Palermo allo sviluppo dell’astronomia nel corso della sua pluricentenaria attività scientifica, soffermandosi sui periodi più significativi e sui fattori che hanno determinato gli importanti risultati scientifici ottenuti, dalla fine del Settecento agli ultimi decenni del secolo scorso, dagli astronomi in forze all’Osservatorio.

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