Direct imaging is a technique that allows us to spatially resolve the planet from its host star. Due to the big difference in flux between star and planet, a very high contrast must be reached to observe the planet that would be otherwise hidden in the glare of the star.
Coronagraphs are optical systems that work as angular filters, suppressing the on-axis star light and letting the...
Pulsar Timing Array (PTA) projects hold the promise of becoming sensitive Gravitational-Wave (GW) detectors in the nanoHertz frequency band. Multiple international PTA collaborations are actively timing an array of pulsars with their respective radio observatories, and each collaboration carries out GW searches in their own data. In principle, a combined search over all available PTA data is...
Unlucky stars that venture too close to a supermassive black hole (BH) get ripped apart by gravitational tidal forces. These tidal disruption events (TDEs) offer a rare probe of otherwise quiescent BHs.
TDEs are usually detected in the optical and ultraviolet (UV), where light curves show an early-time peak, often followed by a late-time plateau. Recent modelling shows that these plateaus...
Astronomical instrumentation projects are often very international, with team members coming from different cultural backgrounds, being proficient in multiple different languages, working across different time zones, and frequently having a different (professional) understanding of the same โย often English โ working language.
In this talk, I would like to share my personal and professional...
We see considerable political pressure against "DEI" (Or EDI, Equity, Diversity and Inclusion). We still have more freedom of speech on this than our colleagues in the USA (where I previously lived and worked for 20 years);
We need to address the question of how we can explain to guys like Donald why EDI matters, what it is and what it isn't. Much of the time we are "preaching to the...
The European Regional Office of Astronomy for Development (E-ROAD), part of the International Astronomical Unionโs global OAD network, harnesses astronomy to drive societal progress and contribute to the United Nations Sustainable Development Goals (SDGs). Based at Leiden University, E-ROAD focuses on quality education (SDG 4), gender equality (SDG 5), economic growth (SDG 8), and reducing...
Ground-based observations of spacecraft signals have been used to study space weather. However, single spacecraft measurements observed from the Earth have limitations in studying the structure and evolution of solar plasma as they are unable to differentiate spatial and temporal variations. To overcome this limitation and improve our understanding of interplanetary scintillation, we...
After more than 30 years of talking, the construction of the Square Kilometre Array (SKA) is now well underway. In this talk, I will give a update on construction, discuss how anyone can get involved in the SKA now, and what this stage of project development means for the Dutch astronomy community. In particular, I will focus on the establishment of our own regional centre, and its expected...
The Advanced Telescope for High-Energy Astrophysics (Athena) has successfully completed a redefinition phase โ both of the technical implementation, and mission driving science objectives โ becoming โNewAthenaโ. With mission adoption by ESA foreseen in early 2027, the activities of the NewAthena Science Community are expected to ramp up in the very near term. I will give an update on the...
Since 2020, Microsoftโs emissions have risen by more than 30%, and Googleโs by almost 50%. The reason, according to both companies, is the insatiable energy demand of generative AI. As a result, both companies are now openly wavering on their previous corporate emissions targets and making it clear that AI growth will take priority over achieving any climate goals.
To put it another way:...
The NOVA Submillimeter (submm) Group was established at the Kapteyn Astronomical Institute in 1998 as part of the Netherlands Research School for Astronomy (NOVA) instrumentation effort. Its primary goal was to develop technology for the ALMA project. This focus shaped the group's research and development direction, particularly in the field of low-noise heterodyne receivers for submillimeter...
The impetus for wide-field searches for counterparts of explosive transients including binary neutron-star mergers, supernovae, and tidal disruption events has never been higher. The ongoing operations with the LIGO-Virgo network of gravitational wave detectors in the 4th observing period continues to offer challenges for optical observers, primarily due to the poor (~100 deg$^2$) localisation...
