Netherlands Astronomy Conference 2025

As KNA/RNAS Chair I wish to open the conference, during a 10min presentation in which I also shall recall the WWII episode of the Society. After the 10min I will hand over to the LOC Chair.

HARPS3 is a high resolution (R~115,000) stabilized Doppler spectrograph covering a wavelength range from 380-690nm with polarimetric capabilities that is coming online on the roboticized 2.5m Isaac Newton Telescope (INT) at La Palma in Fall 2025. HARPS3 is designed to enable ~10cm/s radial velocity (RV) precision on nearby bright solar-type stars to enable the detection of Earth Twins. The...

I will present the status of WEAVE, the new wide-field spectroscopic survey facility for the William Herschel Telescope at the ING, and some early science results. WEAVE has been operational in its Large Integral-Field Unit (LIFU) mode since late 2022 and is presently commissioning its MultiObject Spectroscopy (MOS) and mini-IFU (mIFU) modes. I will present the instrument performance in the...

One of the remaining unsolved questions is the one of globular cluster formation, as there is still no definite consensus on whether the clusters have formed within the Milky Way galaxy (in situ) or have been accreted. Current estimates suggest that between 25-65% of all Milky Way GCs were accreted, however the exact number is still uncertain. Since GCs are significantly old (up to 12 Gyr),...

In June 2023, International Pulsar Timing Array (IPTA) collaborations in Europe, America, India and Australia simultaneously announced the first compelling evidence of the low-frequency (nHz) gravitational wave background. This was a milestone in gravitational wave astronomy. These results were further strengthened by detailed comparative analysis at the IPTA level. The main source of noise in...

Astrophysical research is increasingly leveraging data science, statistics and machine learning, with applications ranging from detecting transients in images to inferring exoplanet atmospheres. However, studying the most energetic phenomena in the universe presents particular challenges, including comparatively small, heterogeneous datasets and a lack of reliable training data. This talk...

Fast radio bursts (FRBs) are one of the most exciting mysteries in contemporary astrophysics. They last only a fraction of a second but are bright enough to be detectable from halfway across the Universe. FRBs are unique astrophysical tools: they are perfect point sources, impulsive, and being in the radio band they are also distorted in ways that carry valuable information about otherwise...

Massive stars are chemical factories, they are progenitors of supernovae, neutron stars and black holes, and they play a crucial role in the formation and evolution of their local environment as well as their entire host galaxies. Given their prevalence in close binary systems, at the end of their lives they may produce double-compact objects, which are potential gravitational-wave sources....

Exoplanets are not only ubiquitous, but diverse in nature. The mechanisms governing their formation and evolution remain elusive, yet theoretical modelling suggests that the atmospheres of gaseous worlds can offer clues into their history. However, due to the required precision on these measurements, studying planets individually is not sufficient to test these models: one must conduct...

Gravitational waves (GW) are providing a new way to study the properties of compact objects. In this context, understanding what determines the final fate of stars, the role of binary interactions, and which signatures to expect in GW observations is becoming increasingly important. The formation of black holes (BHs) or neutron stars (NS) is not a simple function of the initial mass of a...

How the chemistry in the universe evolves from diffuse interstellar medium to a life-harboring environment on our Earth? Complex organic molecules (COMs), typically defined as carbon-bearing molecules with at least six atoms, have gained their popularity over the past several decades due to their importance of linking atoms and simple molecules with prebiotic species. COMs are suggested to be...

In the past decade, hundreds of exoplanets have been discovered in extremely short orbits below 10 days. Unlike in the Solar System, planets in these systems orbit their host stars close enough to disturb the stellar magnetic field lines. The interaction can enhance the star's magnetic activity, such as its chromospheric and radio emission, or flaring. So far, the search for magnetic...

Accretion and outflows are astrophysical phenomena observed across a wide range of objects, from white dwarfs to supermassive black holes. Developing a complete picture of these processes requires complementary studies across this full spectrum of jet-launching sources. In particular, jet–interstellar medium interaction sites near black hole X-ray binaries provide an indirect probe of the...

The Event Horizon Telescope (EHT) has imaged the black hole shadows of the supermassive black hole at the center of the galaxy M87 (M87) and at the center of the Milky Way (Sgr A), using the technique of very long baseline interferometry (VLBI) at 230 GHz. In the future, black hole imaging will transition to movie making with ground-based upgrades and extensions of the EHT array. However,...

The Habitable Worlds Observatory (HWO) is the next flagship of NASA, planned to be launched in the 2040s. With a wavelength coverage from the ultraviolet to the near-infrared and a suite of multi-purpose instruments, this observatory will be a successor to the Hubble Space Telescope. It will be the first space telescope designed specifically to directly characterize Earth-sized exoplanets...

Gaia is revolutionising our understanding of the Milky Way and can be used for research in many different areas of astronomy, ranging from solar system science to quasars. One field where the Gaia astrometry excels is the study of so-called runaway stars. Runaway stars move away from their birth region with a high peculiar velocity. The high-mass runaway stars can efficiently and effectively...

Constraining the Epoch of Reionization remains one of the pivotal tasks of modern cosmology, and next-generation telescopes are opening up the path to the first precision constraints on the timing of reionization derived from the Lyman-$\alpha$ damping wing signature imprinted on the spectra of high-redshift quasars by the foreground neutral intergalactic medium (IGM). In the coming years,...

Understanding the processes that drive the quenching of star formation in galaxies is crucial for unveiling the mechanisms that shape galaxy evolution. Quenching transforms actively star-forming galaxies into passive systems on very short timescales of a few hundred Myr, influencing the overall structure, morphology, and chemical composition of galaxies across cosmic time. Investigating...

Recently, we have with LOFAR successfully imaged several deep fields at sub-arcsecond resolutions (e.g. Lockman Hole, ELAIS-N1, and Boötes), revealing the distant universe below 200 MHz in unprecedented detail. However, this has come at the expense of significant computing resources and extensive manual intervention, making it unsustainable for large-scale surveys or ultra-deep wide-field...