The Leiden/ESA Astrophysics Program for Summer Students (LEAPS) 2018
Update: January 30th, 2018
New projects have been posted!
Leiden Observatory and ESA are pleased to welcome applications for the sixth
edition of the LEAPS program. Application are carried out through this
application form and the deadline is scheduled for February 23, 2018.
If you have any questions about the application process or the program, please
. If you want to know more about
the projects on offer, please email the project supervisor directly by clicking on
their name below.
LEAPS is an opportunity for students with an interest in astronomy and astrophysics to perform a 10-12 week summer research project in
collaboration with a research scientist from Leiden Observatory or ESA.
The program is open to all students not currently engaged in a Ph.D. program,
although most past participants have been senior-undergraduate or masters' students who are enthusiastic about research in astrophysics.
Students will be selected for the program based on their academic achievements
and research potential, and will be matched to staff projects based on what they
indicate their scientific interests to be. Research at Leiden Observatory and ESA
takes place on a diverse array of topics (see below), and
student projects will likely consist of anything from the analysis of data from
world-class telescopes, to large computer simulations, to hands-on work in the
Projects will begin in June 2018 and end by mid-August 2018.
Leiden Observatory (located in the Huygens and Oort buildings) is a world-class institute for research in astronomy and astrophysics based in the Netherlands, approximately 35km from Amsterdam. The atmosphere at the observatory is dynamic, with approximately 100 faculty/research scientists and 70 graduate students engaged in astrophysical research on a wide range of topics. Major fields of interest include extrasolar planets, star formation, cosmology, galaxy formation, instrumentation, and astrochemistry. Multiple research projects will likely be available within these fields.
European Space Research and Technology Centre (ESTEC/ESA)
ESTEC is the main technical centre for the European Space Agency (ESA), responsible
for spacecraft integration. ESA develops and manages many types of space missions,
from exploration, telecommunications, to earth and space science. The Research and
Scientific Support Department at ESTEC consists of approximately 40 staff scientists,
with research interests ranging from the geology of planets in our solar system, to
plasma physics in the magnetosphere of the Earth, space weather, to observational
astronomy with ESA's space missions such as Planck, Herschel, GAIA and EUCLID. Due to
tight security requirements for entry to the ESTEC complex, students who work in
collaboration with the ESTEC Research Fellows will be based primarily at Leiden
Observatory and their advisor will meet with them on a regular basis.
Travel, Housing and Stipend
Students accepted into the LEAPS program will be provided with travel costs to/from
Leiden. We will also provide housing accommodations near the observatory, as well as a
modest stipend to help with living costs during the internship. Leiden is a small,
picturesque university town located between the major cities of Amsterdam and The Hague.
Summer is a beautiful time of year to be in Leiden, and we encourage LEAPS students
to socialize and use their free time to enjoy the numerous summertime activities
available in Holland. English is widely spoken throughout the Netherlands and
international students should find it easy to live in the Leiden area. We are
planning several field trips for LEAPS students including visits to the ESTEC complex
where many ESA satellites are being built, and potentially to the LOFAR radio array,
the world's largest low-frequency radio telescope.
How to Apply
The program is open to all international students provided they are not currently enrolled in a Ph.D. program. ESA projects are only available for students from ESA member
or affiliate states (Austria, Belgium, Czech Republic, Denmark, Estonia, Finland, France,
Germany, Greece, Hungary, Ireland, Italy, Luxembourg, The Netherlands, Norway, Poland, Portugal,
Romania, Spain, Sweden, Switzerland, the United Kingdom and Canada). Students from
Bulgaria, Cyprus, Malta, Latvia, Lithuania, Slovakia and Slovenia (affilliate members) can also apply for ESA projects. The working language of the observatory is English, and students should
be sufficiently proficient in English to perform a research project.
Deadline for applications: February 23, 2018, 23:59 CET
If you have any questions about the application process or the program, please
. If you want to know more
about the projects on offer, please email the project supervisor directly by clicking
on their name below.
LEAPS 2018 Poster: coming soon
Research Projects, Categories and Supervisors
These are the proposed research projects for LEAPS 2018. Please note that not all
projects will go ahead and some may still be added in the near future. Final funding decisions
lie with the Faculty sponsors. And please make a note that if you are interested in an ESA project,
to check if your state is an ESA member or affiliate state.
Project list (updated Jan 30 2018):
Low-frequency VLA observations of a massive colliding galaxy cluster
Type of project: Observational, galaxy clusters, radio observations, particle acceleration
Galaxy clusters grow by mergers with other clusters and galaxy groups. Galaxy cluster mergers are the most energetic events in the Universe. During this process shocks and turbulence are created in the cluster plasma. These shocks and turbulence can accelerate cosmic rays which will then emit synchrotron radiation which can be detected by radio telescopes. For this project, new low-frequency Very Large Array observations of a massive merging galaxy cluster will be analyzed with the aim of imaging radio emission from cosmic rays in the cluster.
Characterizing protoplanetary disks; Initial conditions for planet formation
Type of project: Modeling; planet formation, circumstellar disks
As the earliest stage of planet formation, massive, optically thick, and gas rich protoplanetary disks provide key insights into the physics inherent in star and planet formation. These disks provide the environment, literally the birthplaces, for planets to form. The question is how? How do gas and dust interact in protoplanetary disks? On what timescales do disks evolve, and how does this depend on the stellar mass, metallicity and environment? The answers to these questions depend on the disks’ estimated lifetimes, estimated total masses and, critically, on their internal densities.
This project aims to address these questions through comprehensive model fitting of protoplanetary disk data from the Hubble Space Telescope. The student will combine existing HST images with a spectral energy distribution to model the key structural parameters such as the geometry (disk outer radius, vertical scale height, radial flaring profile), total mass, and dust grain properties in the disk using the radiative transfer code MCFOST.
Investigating the accuracy of SED fitting codes in constraining galaxy properties in the era of MUSE and JWST
The development of sensitive multiplexed instruments in ground and space based telescopes have enabled astronomers to obtain large samples of photometric/spectroscopic data of galaxies over cosmic time. The combined coverage of MUSE observations with future JWST deep surveys will add rest-frame optical and infra-red coverage to galaxies from cosmic dawn to cosmic noon. The physical and chemical properties of these galaxies will be inferred by fitting observed data to synthetic spectral energy distributions (SEDs) using various synthetic stellar population models and SED fitting codes. These models and fitting codes implement various techniques to infer properties of galaxies, however, there is limited study done on comparisons between these models/techniques.
This project will explore several synthetic stellar population models to generate a grid of galaxy SEDs ranging a range of physical and chemical properties. The generated models will then be used to computed synthetic photometry/spectroscopy with reasonable noise/resolution properties expected from MUSE and JWST NIRSpec. The computed data will be fed through several commonly used SED fitting codes to investigate and cross-examine the accuracy of predictions with input values.
Through this project, the student will gain basic experience in generating model observations, SED fitting, and instrumental properties of the most cutting-edge instruments and will be placed at a competitive advantage for PhD positions in the era of JWST.
How is galaxy color tied to dark matter?
Type of project: Observational; galaxies, dark matter
Galaxies are formed in collapsed structures known as dark matter halos. One of the common assumptions is that galaxy properties can be fully characterized by their Host halo mass. At any given redshift, galaxies fall into two main groups: (1) blue and star forming galaxies, and (2) red or passively evolving (also known as quenched) galaxies.
One of the outstanding questions in modern structure formation is whether galaxy properties are correlated with their large-scale environment. The quenched fraction of centrals (galaxies that reside in the center of halos) may be correlated with the large scale density at fixed halo mass. However, the existing results based on observations and simulations remain conflicting. This project aims to contribute to our understanding of structure formation by investigating the observational relation between the fraction of red (quenched) centrals and local density of galaxies in filaments, groups, and voids using the SDSS main galaxy catalog.
Exploring the composition of the beta Pic debris disk in the far-UV
Type of project: Observational; debris disks, Hubble, exocomets
The Beta Pictoris system is a young planetary system embedded in a debris disk that is continually replenished by the collision and evaporation of planetesimals and exocomets. Observing this system in the far-UV provides information on the abundance of atomic species such as oxygen, carbon and silicon.
The student will work closely together with Dr. P. A. Wilson on a completely new set of Hubble Space Telescope data (to be obtained in the spring). Together they will measure the abundances of many important species in the debris disk and compare these to the composition of meteorites and comets in the solar system. Such work will result in new information on the processes taking place in this active system during the last stages of the planet formation.
The project involves analysing observational data using python. The work will be aimed at publishing a paper with the possibility of the student becoming a co-author.
Telling discs from mergers with ALMA
Type of project: Simulation; high-redshift, ALMA, galaxies, star formation
The recently build ALMA interferometer, a new large array of mm-wave telescopes, allows us to study very distant (redshift 2-5) galaxies in detail for the very first time. An especially interesting target are intensely star-forming galaxies, which are quiet unlike any in the local Universe. The nature of these galaxies is still unclear – are they a result of galactic mergers, or massive disc-like galaxies? But at such a distance, even with the full power of ALMA, galaxies are often too faint and compact to be properly resolved. Consequently, distinguishing a large disc galaxy from a merging ones is a difficult task. This explorative project will simulate ALMA observations of both disc and merging galaxies at thigh redshift, and investigate how well can we classify these galaxies based on simulated ALMA data.
Early evolution of embedded proto-clusters
Type of project: Observational; star-formation, radioastronomy, ALMA
Characterizing the early evolution of young stellar clusters is of
paramount importance in our current description of the star formation
process in the Milky Way. The fate of these systems is largely
determined by the dynamical state of its gas and stellar components.
Contrary to the classical paradigm for cluster formation, recent
numerical and observational results suggest that both stars and gas are
independently virialized during at first stages of cluster evolution.
Combining the spatial resolution and large-scale mapping capabilities of
the ALMA Compact Array (ACA), in this project we will investigate the
kinematic properties of a selected subsample of 6 intermediate-mass
clusters in the Orion A cloud.
Studying galaxy mergers using the deep learning approach
Understanding the driving mechanisms of galaxy morphologies is a fundamental challenge in galaxy formation studies. It is widely believed that galaxy mergers produce irregular galaxies. In principle, the shape of an irregular galaxy can be used to constrain the properties (e.g., mass ratio, impact angle, etc.) of the progenitor merger galaxies. In practice, however, it is highly challenging to quantitively obtain these properties merely from the telescope images. This project is an exploratory study aiming to tackle this challenge using the deep learning approach. A deep neural network (DNN) will be constructed using Tensorflow. The DNN will be trained using a large number of galaxy merger simulations. Once trained, the DNN will be capable of providing the merger properties of irregular galaxies based on telescope images.
Observing planet-forming disks: linking ALMA to JWST
Type of project: Database mining, observational, star/planet formation
James Webb Telescope (JWST) will provide a new window into the studies of planet-forming disks in the mid-infrared. In the millimeter regimes, Atacama Large Millimeter Array (ALMA) has revolutionized our understanding of these disks with its spatial resolution. The same planet-forming disks observed by ALMA will be targeted by JWST.
The project is a preparatory work for JWST. The student will set up a database gathering ALMA data and other complementary data for the JWST targets. The preferred tools will be Django and angularJS.
The dynamical origin of the flattening of globular clusters
Globular clusters (GCs) are among the oldest stellar systems we know, and as such they retain information on the properties of the early Universe. Studies of their structure and dynamics provide insights to understand not only their evolution, but also the formation and evolution of their host systems.
GCs are nearly gas-free, self-gravitating stellar systems characterised by an apparently simple geometry. Indeed, for a long time they have been approximated as spherically symmetric, non-rotating, isotropic systems. However, this simple physical picture suffers from a number of limitations, which become more evident now that much improved observations have become available. The most obvious deviation from these assumptions is the fact that some GCs are flattened. This flattening could be caused by internal rotation, by the interaction with the external tidal field, or by pressure anisotropy. The purpose of this project is to investigate which of these dynamical ingredients is responsible for the observed shapes of three Galactic GCs (NGC 5897, NGC 6273, and NGC 6541).
To do this, the candidate will: (1) analyse FLAMES data (already available on the ESO archive) to measure line-of-sight velocities of single stars in these GCs; (2) combine these data with Gaia proper motions (Gaia Data Release 2, April 2018) to compute velocity dispersion, rotation, and anisotropy profiles; (3) fit the data with adequate models to provide a detailed dynamical analysis of these systems, and to determine the origin of their observed morphology.
Ultra-deep spectroscopy with MUSE
Type of project: Ovservational, spectroscopy, galaxies
The MUSE spectrograph on the Very Large Telescope is one of the most technologically advanced instruments in the world. MUSE is an "integral field unit," meaning it obtains a spectrum from every pixel within its field-of-view. We have begun to take large surveys with MUSE, specifically looking at very distant galaxies in the Hubble Ultra Deep Field. With such a wealth of spectral information, we need new software tools to interpret the data. In particular because we now have the largest unbiased sample of intermediate- and high-redshift galaxy spectra covering the restframe ultraviolet. Spectral features in this region are full of information about the physical state of the galaxy's interstellar medium and the nature of the sources of ionizing photons. By combining multiple spectra from galaxies, we can obtain even higher signal-to-noise data. The ability to dynamically select the input sample is crucial to learn about the average properties of different galaxy populations, so the LEAPS student would create a tool for creating these stacked spectra. Ideally, we would use it to create a definitive restframe-ultraviolet template for "typical" high-redshift galaxies, which would be utilized to make predictions for observations with the upcoming James Webb Space Telescope.
Evaluating large-scale public engagement programmes and understanding grassroot participation
During this project, the student will explore the effectiveness of large-scale public
engagement programmes to reach its target audiences and the motivations behind the
organization of grassroots activities in the framework of these type of initiatives.
By reviewing best practices and evaluating previous initiatives in the context of the
International Year of Astronomy 2009 and the International Year of Light and Light-based
Technologies 2015, the student will conduct an study of the feedback received from activities
celebrated worldwide around the first edition of UNESCO’s International Day of Light on 16
May 2018. The findings of this research will serve as basis for evaluation purposes of the
International Astronomical Union 100th Anniversary Celebrations.
Surface characterization of ancient terrains on Mars using orbital imaging datasets
Type of project: Image processing, remote sensing, planetary science, ESA ExoMars, ESA
The planet Mars is hosting very ancient terrains, dating about four billion years old, that have been identified as crucial for our understanding of the early evolution of terrestrial planets and the emergence of life on Earth and potentially elsewhere. Space agencies and the planetary science community are dedicating important efforts into the characterization of these ancient terrains by remote sensing and in situ investigations. The successful candidate will have the chance to delve into imaging datasets that are currently being acquired by two spacecraft orbiting around Mars, the ESA Trace Gas Orbiter and the NASA Mars Reconnaissance Orbiter. The datasets will be exploited in the USGS ISIS environment for the production of digital elevation models in order to combine topography with high resolution imaging of the surface. Geological analyses will include mapping and stratigraphy reconstruction and can be coupled with automated spatial analyses of high-resolution images. An emphasis will be given to the characterization of landing sites for the upcoming ESA ExoMars mission.
Properties of radio sources in different cosmological environments
Radio emission from compact sources in galaxy clusters have different properties from the average population. The aim of the project is to assess the effect of the cosmological environment on radio emission generated by active galactic nuclei. This is an important piece of the puzzle to understand the life-cycle of radio galaxies and their impact on galaxy and galaxy cluster evolution. The student will use recently published radio data (http://tgssadr.strw.leidenuniv.nl/spidx) in combination with existing catalogs of galaxy clusters to identify the emission/spectral/morphological properties of the radio sources with respect to the large scale environment. The project requires skills in python programming, big data analysis and basic understanding of radio astronomy.
Corroborating lunar impact flash locations with evidence in visible and infrared observations from Lunar Reconnaissance Orbiter
12 years after the man-made impact of the SMART-1 lunar satellite on the lunar surface and the study of the resulted crater, we are in a position to have detected hundreds of these events produced by small near-Earth objects (origin from asteroids and comets) hitting the Moon. The ESA-funded project NELIOTA has detected tens of new impact events on the lunar surface. These detections were possible by operating a telescopic monitoring survey of the flashes that are generated during an impact event. We have developed methods to estimate the size of the impacting body and, with the help of scaling laws, the size of the formed crater. In that way we will have an excellent dataset of impact events, knowing several parameters, enabling us to study the impact physics and the impacting population. Since 2009 NASA's Lunar Reconnaissance Orbiter has acquired high resolution visible images and thermal infrared measurements of the lunar surface and these will be the input of the study. This project is to develop an implement a methodology using LRO data to search the lunar surface around the locations of each impact to detect the craters formed, such that their sizes can be measured. The successful candidate should have experience programming in an analysis language (Matlab/IDL/Python) as well as image processing.
Unbiasing gravitational lensing shear
Type of project: Galaxy image simulations, observations
The matter distribution in the Universe is far from being uniform at small scales, resulting in a tidal gravitational field. The phenomenon of gravitational lensing acts a tool by letting us infer the distribution of dark matter in the Universe through the effects on photons from the background light sources. The observable quantity in lensing is a complex-valued, gravitational shear field, which can be calculated from the shapes of background galaxies. The measured shear, is not identically equal to the true shear, but is also a function of various other factors such as the noise level (or signal-to-noise ratio), galaxy size, knowledge of the galaxy profile etc. Thus, the measured shear is said to be a biased estimate of the true shear. In the weak shear limit, the measured shear function is expressed as a Taylor expansion to first order, with a constant term and a multiplicative bias term. These bias terms are typically estimated through galaxy image simulations and calibrated out. In addition to the reasons mentioned above, many subtle effects, such a bright neighboring galaxy, also contribute to the biases. The student will work on simulating galaxies investigating such effects. This project would act as a baseline for an entire class of shape measurement algorithms. Depending on the interests of the student, there will also be scope to use real observed data for this project. Additionally, the student will have the option of investigating if standard calibration model commonly employed is also sufficient for the next generation high-precision surveys.
Enabling high-priority astronomy for miniaturized satellites
Type of project: Instrumentation, satellite miniaturization, payload data handling, data processing, FPGA, microcontroller, Cubesats
Miniaturized Satellites have revolutionized space science and engineering and are fundamentally changing space exploration and spacecraft engineering.
Today, CubeSats and other Nanosatellites can be developed at a rapid pace, using well tested but low cost off-the-shelf mobile-market hardware.
Many of today's scientific instruments fit very well into such smaller spacecraft, enabling on-orbit research and science verification missions which would have been impossible with larger spacecraft just few years ago.
In this project, we will investigate how the detector/CCD readout pipeline of a large satellite such as Hubble or JWST can be realized aboard a miniaturized satellite.
Students can research how a detector akin to those in JWST/NIRSpec and MIRI and various ground-based telescopes could be utilized with miniaturized satellite hardware, either in a software-centered project or a hardware-focused one.
Students curious about looking into a real-world data acquisition and reduction pipeline for such a CCD, should be proficient with at least one high-level programming language (e.g. C).
Others interested in how astronomical data is generated by a CCD and reduced in an FPGA or µController, should have experience either in microcontroller programming, electronics, logic design, or space engineering for instrumentation.
Photochemistry in the atmospheres of Hot Jupiters
Type of project: Theoretical; chemical modeling, synthetic spectra, exoplanetary atmospheres
The chemical content of (exo)planetary atmospheres is an active area of research, representing a main focus of the next generation of observatories like the James Webb Space Telescope (JWST). Cataloguing the total elemental abundances of common species like carbon, oxygen, and nitrogen is important for understanding the physical processes that are occuring in planetary atmospheres, as well as the formation history of planets. These studies are complicated by internal atmospheric transport and chemistry that hide a substantial fraction of some elements.
The purpose of this project is to assess the detectability of nitrogen carriers (eg. HCN, NH3) in exoplanetary atmospheres with JWST. The applicant will use a photochemical code to compute the conversion of molecular nitrogen into NH3 and HCN intiated by UV photodissociation at different positions in the atmosphere of a Hot Jupiter. Given these results, we will produce synthetic transmission and emission spectra for transiting planets as seen by JWST. The applicant should be comfortable using programing languages like Python.
Observability of hot super-Earth atmospheres
Type of project: Exoplanets, exoplanet atmospheres, radiative transfer
Super-Earths are an exotic kind of planets. With masses of approximately 10 MEarth, they are an intermediate between rocky and giant planets with no parallel in our solar System. For this reason, the composition of their atmospheres remains mostly unknown. Many dozens of these planets have been detected and the era of their characterisation is just starting.
The idea of this project is study the spectra of hot (T>1000K) super-Earths atmospheres of different atmospheric composition and asses their detectability
with current and future instrumentation. The applicant will use a radiative transfer code (python, fortran) to model the synthetic transmission and emission spectra of these exoplanets and a tool (python) to estimate the error when observing them with James Webb Space Telescope.
Please note that the ESA projects are only available for students from ESA member or
affiliate states (Austria, Belgium, Czech Republic, Denmark, Finland, France,
Germany, Greece, Ireland, Italy, Luxembourg, The Netherlands, Norway, Poland,
Portugal, Romania, Spain, Sweden, Switzerland, the United Kingdom, and Canada). Students
from Cyprus, Estonia, Hungary, Latvia and Slovenia (affilliate members) can also apply
for ESA projects.
Past LEAPS Successes
LEAPS 2015 was a great success! Twenty-two students from four continents spent their
summer in Leiden doing astrophysics research.
Joshua Borrow (with supervisor Pedro Russo) published a paper on astro-ph
entitled "A Blueprint for Public Engagement Appraisal: Supporting Research Careers."
Lukasz Tychoniec (supervised by John Tobin) presented his research at the
Polish Astronomical Society Summit, and his research already contributed to
one published paper and he is preparing a paper on the full results.
Tessa Wilkinson (supervised by Anna-Lea Lesage) presented her research at the
2016 American Astronomical Society meeting.
Jeremy Dietrich (supervised by Christian Ginksi) submitted a paper to MNRAS
"Archival VLT/NaCo multiplicity investigation of exoplanet host stars".
Maria Vincenzi (supervised by Carlo Manara) presented a poster at the workshop:
"The accretion/outflow connection in YSOs" at ESTEC in October and a paper is
Hope Boyce (supervised by Nora Lutzgendorf) presented a poster at the
Canadian Conference for Undergraduate Women in Physics and a paper is in
The 2013, and 2014 groups of LEAPS students also performed very well and the first
scientific publications are out!
Ryosuke Goto and his advisor Sean McGee published a paper on galaxy formation in
the Monthly Notices of the Royal Astronomical Society on his LEAPS project;
"The stellar mass function and efficiency of galaxy formation with a varying
initial mass function".
Steffi Yen and her advisor, Adam Muzzin, presented a poster at the
American Astronomical Society (AAS) winter meeting in Washington DC, "Searching
for the Most Distant Galaxy Clusters". See
Fiona Thiessen and her advisor Sebastien Besse submitted a paper on Lunar
surface composition and lava flows (figure below).
Conny Weber worked with Agnes Kospal on infrared variability of young stars
in Chamaeleon which featured on a poster at the "The Universe Explored by
Herschel" conference in Noordwijk
See the poster here.
Hannah Harris, a 2014 LEAPS student, and her advisor Pedro Russo published a
paper in the Space Policy Journal, "The Influence of Social Movements on
Space Astronomy Policy." See here.
Saul Kohn (now a PhD student at UPenn) and his advisor David Sobral published a
paper in Monthly Notices of the Royal Astronomical Society on his LEAPS project:
"The most luminous Halpha emitters at z~0.8-2.23 from HiZELS". See here
LEAPS student Michael Hammer (from Cornell University) and his adviser
Lucie Jilkova studied close stellar flybys that lead some stars to lose parts of
their circumstellar discs. Using simulations in the AMUSE framework
(www.amusecode.org), they showed that if the two stars approach each other
close enough, part of the disc lost from one star can be transferred to the other
one. These close encounters can happen shortly after stars form when many stars
are clustered together. They further showed that even our Solar System might
have experienced such an interaction and stolen some material, which is now
orbiting in its outer parts, from another star. Michael presented a
poster on the results of his LEAPS project on the 225th
AAS meeting. The project eventually resulted to
publication in an international refereed journal, which led
to several press releases, for example:
New Scientist, Scientific American, Universe Today.
Figure of the submitted paper by Fiona Thiessen, students of the LEAPS 2013 class.
(a) M3 color composite image of the Imbrium basin (red: IBD1000, green:
IBD2000, blue: R750 nm). Numbers indicate the basalt units mapped in this work. Large
and spectrally bright craters are mapped separately in grey and were excluded from the
basalt units. The surrounding highlands and kipuckas inside the Imbrium basin are also
shown in grey. Dark strips correspond to portion of the lunar surface not observed
with M3 using OP1B. (b) Eratosthenian basalt flows from Schaber  with
flow phases I-III.
ESTEC group picture (joint tour with ASTRON summer school).
The rain could chase us away from LOFAR! (not quite drenched yet in this picture).
The 2013 LEAPS students (and some supervisors) on their visit to the Westerbork
Radio telescope in Dwingeloo, the Netherlands.