Recent Talks

MHD waves – slow, Alfvén and fast – lose their distinctiveness in certain regions of a stratified plasma, such as solar or stellar atmospheres. We discuss all three mode conversion processes, fast/slow, fast/Alfvén and slow/Alfvén and how they are affected by atmospheric structure, magnetic field orientation, and partial ionization. We also present some simulations of fast/slow coupling in shock waves.

El telescopio solar EST, con su espejo primario de 4.2 m, será uno de los mayores telescopios solares del mundo. Uno de los instrumentos que se instalarán en EST es EMBER (EST spectropolariMeter Based on slicer-mirrors for the near-infraRed). El instrumento es un espectropolarímetro de alta resolución espacial y espectral que trabajará en el infrarrojo cercano (1.0 a 1.8 micras). Tendrá una resolución espacial de 0.1’’ y observará un campo de visión (FoV) simultáneo de 10’’ x 10’’. Para poder cubrir ese FoV, llevará incorporada una Unidad de Campo Integral (IFU) basada en espejos rebanadores. Su espejo rebanador, situado en el foco, secciona la imagen. Después un sistema óptico reorganiza los haces generando, en este caso, varias rendijas de salida, que serán la entrada al espectrógrafo. En esta charla, se presentará un diseño conceptual de la IFU que está basado en la unidad actualmente instalada en el espectrógrafo GRIS del telescopio solar GREGOR. La mayor diferencia está en el gran campo de visión que le llega, pasando de un slicer de 1.8 x 3 mm con 8 rebanadas a uno de 10 x 10 mm con 400 rebanadas, lo que supone un gran reto para su diseño y fabricación.

Stellar models are a crucial ingredients for a pletora of fundamental research fields in Astrophysics: from the planet-host stars to Galactic Archaeology, from fundamental Physics to the study/understanding of far-away unresolved galaxies, from helio/astero-seismology to exotic stellar objects such as Blue Stragglers, Blue Hook stars, millisecond pulsars, supernova progenitors, etc. There are various stellar model libraries available in the literature, each one with its own pro and cons; some of them being more suitable for specific research topics. In any case, the use of any stellar model library should not ignore the knowledge of the limitations affecting each library. In this talk, we present the BaSTI_IAC stellar model library that has been developed in the context of a strong collaboration with staff members of the IAC; we discuss the main characteristics of this library, and make a comparison with some of the most commonly used model libraries available in literature. We present also some important recent applications of the BaSTI_IAC library to various scientific problems. At the end we discuss the ongoing effort to improve/extend the library as well as our wish to include additional stellar and sub-stellar mass ranges, with hope to foster new collaborations/synergies with colleagues@IAC.

The elusiveness of neutrinos is most renowned for their ability to penetrate and traverse vast amounts of matter without disturbance. While this very same property makes neutrino detection one of humanity’s most remarkable achievements, recent and forthcoming advancements in instrumentation continue to enhance our ability to harness neutrino-based information as a fundamental tool. This, in turn, provides unique insights into some of the most essential mysteries of the Universe. For instance, shortly after their discovery in the 1950s, neutrinos offered direct confirmation and deeper understanding of the fundamental fusion processes powering the Sun. Today, they are indispensable to our quest for a comprehensive understanding of Earth’s interior, the depths of the Sun, supernovae, high-energy cosmic ray emissions, and the early Universe’s structure following the Big Bang. Furthermore, neutrinos may play a crucial role in our pursuit of the origins of matter and the search for new physics beyond the Standard Model.
In this colloquium, I will highlight some of the most remarkable achievements in neutrino science to date, as well as emerging advancements that have the potential to complement all other cosmic probes — most notably, those within the IAC’s leadership in this field.

The presentation summarizes the tests of the SCT prototype that has been built and tested in the Instituto de Astrofísica de Canarias (IAC) facilities. The objective of this work was to investigate the system performance providing laboratory results to reinforce the validity of the proposed solution, focussing on the most critical performance characteristics of the mechanical design. The Scale Changer is a turret to switch between 4 scales + Pupil Imaging (5 positions), positioning one of the four mirrors at the optical beam or leaving the passage of light free (for selecting the 10x10 scale).

Andrés Parraguez has been part of the NSO team at DKIST for the past seven years. Currently, he holds the position of DKIST Science Operations Manager, having previously served as Chief of the Science Operations Specialist Group. Prior to joining DKIST, Andrés accumulated extensive experience working in engineering projects, science operations, construction, and business development.

His talk, "One Day at DKIST," has been specifically prepared for EST. It highlights the processes within DKIST science operations, as well as providing insights into the informal and practical aspects of daily activities at the DKIST solar telescope.

The Keck telescopes were the first of the generation of 8-10 m class telescopes to implement natural and laser guide star adaptive optics (AO) systems. Over 1300 refereed science papers have been published using data obtained with these systems. The speaker will provide a brief overview of Maunakea and the Keck telescopes, followed by a discussion of the current Keck AO science capabilities, new systems under development, and plans for the future.

Stars and planets formed within the same molecular cloud are inextricably linked in their composition. Alpha-process elements shape planetary cores and atmospheres, with studies showing that key elemental ratios (e.g. Fe/Si, Mg/Si) in planets reflect those of their host stars. While correlations between stellar chemical abundances, planet occurrence, mass and orbital properties have been suggested, definitive confirmation remains difficult due to the subtlety of these trends. Large, homogeneous, high-precision spectral datasets are essential to uncover these relationships. Bright stars (V < 11 mag), such as PLATO's priority-one targets, provide an ideal sample for high-quality stellar and chemical abundance measurements and are expected to yield thousands of new planetary discoveries in the coming years. However, modern multi-object spectroscopic (MOS) surveys often exclude these stars due to their low on-sky density, leading to inefficiencies in conventional observing strategies. The WEAVE-TwiLight Survey (WTLS) solves this problem by introducing a groundbreaking observing mode that optimises efficiency by combining multiple fields into a single fibre configuration. It is expected to produce a homogeneous spectral dataset of ~6,000 bright stars, tailored to probe the chemical relationships between host stars and their planets. In this talk, I will give a general overview of host-star planet relations and discuss the status of the upcoming WEAVE-TwiLight Survey.

On December 25, 2021, the James Webb Space Telescope was launched from Earth towards its ultimate destination at the L2 Lagrange Point, 1.5 million kilometers away from Earth. The culmination of decades of planning, construction, execution, and transport all came down to a critical few minutes, which led to our newest flagship observatory in space. Science operations began in July of 2022, with the past 2+ years bringing about a number of scientific revolutions: both expected, such as the discovery of a number of record-breaking galaxies and other cosmic objects, and unexpected, such as new features in star and planet-formation, and big surprises about the earliest supermassive black holes in our Universe. Come learn what we've discovered and how it's altered our cosmic perspective, and explore how the unheralded concept of "discovery potential" is essential for driving unexpected discoveries at the frontiers of science.

El uso de herramientas de simulación en óptica adaptativa es fundamental para definir requisitos técnicos, comparar configuraciones ópticas, evaluar algoritmos de reconstrucción y desarrollar estrategias de control, con el objetivo de optimizar el rendimiento del sistema. Un simulador de AO debe ser eficiente computacionalmente y flexible para el prototipado de nuevas configuraciones y esquemas de control.

En este seminario, se presentará OOPAO, un simulador desarrollado en Python por Cédric Heritier (ESO, 2023), y se discutirán las mejoras implementadas por el equipo de EST para adaptarlo a aplicaciones en el caso solar y optimizar su rendimiento computacional.