This thesis describes the implementation and on-sky demonstration of high-resolution integral-field spectroscopy for extreme adaptive optics systems that are used to find and characterize exoplanets.

Wetenschappers bij de Leidse Sterrewacht onderzoeken de oorsprong van sterren en hun planetenstelsels. Ze detecteren en karakteriseren planeten rondom andere sterren (exoplaneten). Ze onderzoeken hoe sterren en planeten ontstaan. En ze volgen moleculen van interstellaire wolken tot planetenstelsels…

This thesis describes the Multi-site All-Sky CAmeRA (MASCARA), which consists of two small robotic telescope designed to detect exoplanets around the brightest stars in the sky.

Understanding the formation and evolution of planetary systems is one of the most fundamental challenges in astronomy. To directly image and study young exoplanets and the circumstellar disks they form from, dedicated high-contrast imaging instruments are built.

Over the past years it has been discovered that the population of extra-solar planets is large and diverse.

Promotores: Prof.dr. C.U. Keller, Prof.dr. H.C. Gerritsen

Promotor: Prof.dr. C.U. Keller

Promotor: Christoph U. Keller, Co-promotores: Matthew A. Kenworthy, Frans Snik

This thesis describes the development and validation of new high-contrast imaging techniques, with the ultimate goal of enabling the next generation of instruments for ELT-class telescopes to directly image Earth-like extra-solar planets orbiting around nearby stars.

This thesis aims to demonstrate how the achromatic nature and design flexibility of liquid-crystal optics can be used to improve high-contrast imaging instruments to facilitate detailed exoplanet characterization.

Over the last three decades, the discovery of exoplanets has revealed the boundless variety of worlds beyond our own Solar System⁠. Majority of planetary systems contain short-period planets that are larger than Earth but smaller than Neptune⁠.

This thesis addresses the chemical processes that determine the compositions of giant planet atmospheres.

Promotor: I. A. G. Snellen, Co-promotor: M. A. Kenworthy

One of the key discoveries in exoplanet research over the past decade is the abundance of small planets in our Milky Way. Despite their high numbers, our understanding of their atmospheres remains limited, and it is unknown if they possess atmospheres at all.

Diverse types of exoplanets such as gas giants on close-in orbits (hot Jupiters) and young massive giants on wide orbits (super Jupiters), with no analogs in the Solar System, pose challenges but also opportunities to our understanding of planet formation and evolution.

Detecting planets during their formation stages is crucial for understanding the history and diversity of fully developed planetary systems like our own. However, observing young planets directly is challenging because they are often deeply embedded within their host protoplanetary discs, rich in gas…

More than 5,000 exoplanets have been found over the past couple of decades. These exoplanets show a tremendous diversity, ranging from scorching hot Jupiters, common super-Earths, to widely separated super-Jupiters on the planet/brown dwarf boundary.

A remarkable population of short period transiting rocky exoplanets with equilibrium temperatures on the order of 2,000 K has recently been discovered.

Promotor: I. Snellen, Co-Promotor: M. Kenworthy

Even though more than 4000 extra-solar planets are known today, only a small fraction of these has been captured in an image. To better understand the planet formation mechanisms in solar-like environments we started the Young Suns Exoplanet Survey (YSES).

Until the 1990s, the only known planets were those in our Solar System. Three decades later, several thousand exoplanets have been discovered orbiting stars other than the Sun, and substantial efforts have been made to explore these strange new worlds through spectroscopic analyses of their atmosphe…

One of the key limitations of the direct imaging of exoplanets at small angular separations are quasi-static speckles that originate from evolving non-common path aberrations (NCPA) to which the primary adaptive optics system is inherently blind. The main focus of this thesis is the development and…

Promotor: Prof.dr. A.G.G.M. Tielens, Prof.dr. C. Dominik (UvA)

De Leidse exoplaneetonderzoeker Frans Snik krijgt een Starting Grant van de European Research Council (ERC). Met de beurs van 1,5 miljoen euro gaat hij technologie ontwikkelen om de atmosferen en oppervlakken van aardachtige exoplaneten te bestuderen.

Op donderdag 26 april gaf James Kasting zijn Oortlezing in het Academiegebouw. Kasting was twee weken in Nederland omdat hij was uitgenodigd als Oort Hoogleraar 2018.

Low-mass main-sequence stars like our Sun are continuous sources of outflowing hot magnetised plasma. In the case of the Sun, this is known as the solar wind, whereas for other stars they are called stellar winds.

The field of exoplanet research is rapidly advancing through the development of new technology, observing techniques, and post-processing methods.

This thesis is about the study of hydrocarbons via infrared spectroscopy.

Promotor: Prof.dr. I.A.G. Snellen, C.U. Keller

This thesis focus on the interaction between M dwarf stellar winds and Galactic cosmic rays and the possible effects on the habitability of exoplanets.

Maar liefst vier wetenschappers ontvangen een TOP-subsidie Exacte Wetenschappen van NWO. Het gaat om astronoom Ignas Snellen, wiskundigen Tim van Erven en Charlene Kalle en informaticus Siegfried Nijssen. Met het geld worden tijdelijke onderzoeksposities gefinancierd.

In Duitsland, Amerika en zelfs in Vietnam: overal ter wereld werd de Leidse ontdekking gedeeld van de geboorte van twee planeten. Astronoom Sebastiaan Haffert wist met zijn team voor het eerst meerdere planeten in wording vast te leggen en publiceerde zijn bevindingen in Nature Astronomy. Een unieke…

De lezing vindt plaats op woensdag 29 mei 2013 en is getiteld ‘Building stars, planets and the ingredients for life between the stars’. De Halley Lecture aan de Universiteit van Oxford is opgericht door de wijlen Henry Wilde, bij de terugkomst van de comeet Halley in 1910. De lezing wordt jaarlijks…

Veel hete, op de aarde lijkende planeten buiten ons eigen zonnestelsel begonnen hun leven als gasplaneten. Dat laten Leidse sterrenkundigen zien in een nieuwe online publicatie.

Promotie

Lezing

Promotie

Promotie

Congres/symposium

Een nieuwe manier om het licht van verre planeten te analyseren zou ons bewijs kunnen leveren van buitenaardse planten, schrijft astronomie-auteur Colin Stuart in de New Scientist. In zijn artikel beschrijft hij het werk van de groep van de Leidse astronoom Rob van Holstein. Dit team detecteerde afgelopen…

Een internationaal team van sterrenkundigen onder Leidse leiding heeft na jaren speuren en het tarten van de grenzen van een telescoop, voor het eerst direct gepolariseerd licht opgevangen van een exoplaneet. Ze kunnen uit het licht afleiden dat er een schijf van stof en gas rond de exoplaneet draait…

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Lezing