Special Colloquium
Dr. Sasha Plavin	SCHEDULED

Black Hole Initiative, Harvard University

Blazars exhibit dramatic optical variability, but the precise location of these flares — accretion flow, jet base, or extended jet — remains debated. I present a novel approach using Gaia astrometry together with VLBI to localize the flaring regions directly. Among blazars with strong optical emission from extended jets, I demonstrate a universal pattern: optical flares occur very close to the central engine. These measurements use the latest Gaia DR3 and place a typical flare within ~0.5 mas (a few pc) of the VLBI core position, consistent with an origin in the innermost jet or accretion region. Such a direct localization can constrain electron acceleration and seed photon fields, and provide a model-independent anchor for gamma-ray and higher-energy emission zones. The upcoming Gaia DR4 will bring per-epoch astrometry, sharpening these constraints further.

	Special Colloquium
Dr. Stefano Berta	SCHEDULED

IRAM Grenoble

The New IRAM KID Array 2 (NIKA2) is a dual-band continuum camera operating at the IRAM 30m telescope on the Sierra Nevada, in Spain. It is equipped with three kilo-pixels arrays of Lumped Element Kinetic Inductance Detectors (LEKID) cooled at 150mK. NIKA2 observes simultaneously at 1.2 and 2.0 mm, and has polarimetry capabilities at 1.2 mm. I will introduce the NIKA2 instrument, its state of the art KIDs technology, its current performance and its bright future. I will then present the most recent science results: NIKA2 studies the magnetic fields of massive star forming regions and supernova remnants, the interplay between star formation and interstellar medium components in nearby galaxies, the structure of the intracluster medium in massive clusters of galaxies, and the evolution of the dust cosmic density all the way back to an epoch when the Universe was less than 1 Gyr old. Join me in this journey across the millimeter sky!

	Main Colloquium
Prof. Franco Vazza	SCHEDULED

University of Bologna, Italy

TBD