Interest in ground-based astronomical instrumentation began with our plan to build a modest but strategic telescope on La Palma, Canary Islands (Spain). As a result, the Mercator telescope is operational at the Roque De Los Muchachos Observatory on La Palma since 2001. This telescope and its instruments are specifically designed for long-term monitoring programmes of variability phenomena. The original instruments (P7, a photomultiplier based two-channel photometer, and MEROPE, a CCD imager) were built at the Geneva Observatory (Switzerland) and have meanwhile been retired. They were replaced by new instruments, developed and constructed at the Institute of Astronomy of the KU Leuven. We headed an international consortium, consisting of the Royal Observatory of Belgium, the Université Libre de Bruxelles, the Geneva Observatory (Switzerland), and the Tautenburg Observatory (Germany), that built HERMES, a fibre-fed high-resolution spectrograph. A second new instrument is the Mercator Advanced Imager for Asteroseismology (MAIA), a 3-colour camera optimised for fast-cadence photometry and targeting asteroseismology of compact objects. Finally, we are also involved in the design and development of METIS, the mid-infrared imager and spectrograph for the European extremely large telescope E-ELT.



Concerning space instrumentation, the Institute of Astronomy has played a key role in the calibration of ISO's SWS and of Herschel's PACS instruments in which we are involved at co-PI level. Currently, activities are focused on the development of the MIRI instrument for the ESA share in NASA’s James Webb Space Telescope, the successor of the Hubble Space Telescope. We play an important role in the development and calibration of the SAFARI instrument to be installed on board the future JAXA/ESA mission SPICA. All these space observatories target the infrared range of the electro-magnetic spectrum. In the area of optical space instrumentation, we contributed to jitter corrections for the CoRoT satellite and delivered the CoRoT N3 data product to the CoRoT community, which is based on our variability classifier for the exoplanet field data of the mission. More recent activities concern the delivery of software for the variability classification to be done with the Gaia mission within the DPAC consortium and the development of the instrument simulator for the PLATO mission project.

Besides those concrete institute involvements in instrument development, calibration, and data product delivery, the institute is successful in getting peer-reviewed based access to the instrumentation available at the European Southern Observatory and at other ground-based observatories, to the Hubble Space Telescope and of space missions to which the institute has access as being in a member state of the European Space Agency.


Publications (Selection)




The Mercator telescope is a 1.2 meter telescope with an alt-azimuth mounting located on the Roque de los Muchachos observatory on La Palma, Spain. The telescope is operated by the staff of the Instituut voor Sterrenkunde and was build by the institute in close collaboration with the Geneva Observatory The Mercator telescope is a twin of the Euler telescope on La Silla, Chile and is in scientific operation since the spring of 2001.

The Mercator Telescope


The HERMES spectrograph is a high-resolution fibre-fed spectrograph for the 1.2m Mercator telescope. The design follows a white pupil layout and combines a high resolution (R = 55000-85000) with a wide spectral coverage (380-900 nm) in one single exposure. The design is maximised for optimal throughput. The spectrograph will be mounted on an optical bench in a temperature and pressure controlled room in the Mercator building. The table below gives the main characteristics of the spectrograph.

Hermes Spectrograph


MAIA (Mercator Advanced Imager for Asteroseismology) is a 3-channel optical imager that is currently being built at the Instituut voor Sterrenkunde. MAIA will offer simultaneous observations in three colour bands (SDSS u, g and r+i bands) over a wide field of view and with very short cycle times. This camera particularly targets the asteroseismology of hot sub-dwarf stars but a broad range of applications can benefit from the enhanced imaging capabilities that it will bring to the Mercator telescope.

MAIA Camera


METIS is the proposed mid-infrared imager and spectrograph for the European ELT, Europe's next-generation ground-based telescope for optical and infrared (IR) wavelengths. Covering the L, M and N bands, METIS will offer imaging and medium-resolution spectroscopy over the full wavelength range (3-14 microns), and high-resolution integral field spectroscopy in L and M bands (3-5.3 microns).



Space Instruments




Gaia is an ambitious ESA cornerstone mission that will be launched in 2013. The mission will measure the positions, parallaxes, and proper motions of more than 1 billion stars with unprecedented precision. In addition it will provide time series of brightness of all these objects, and the radial velocities and spectra of 100 million stars. During 5 years, the mission will collect a staggering 20000 DVDs of raw data, which will revolutionize our view on the Milky Way.




The James Webb Space Telescope (also called JWST) is a large, infrared-optimized space telescope planned to be the successor of the Hubble Space Telescope.  JWST is a partner project between NASA, ESA and the Canadian Space agency.  The launch is planned in 2018.  JWST will find the first galaxies that formed in the early universe, an will see stars forming planetary systems. Webb's instruments will be designed to work primarily in the infrared range of the electromagnetic spectrum, with some capability in the visible range.



PLATO is a next generation ESA space mission concept with the goal to perform ultra-high precision photometry of 100,000s of stars to detect planetary transits and to perform asteroseismology. It will provide important and new insight into the statistics and evolution of exoplanetary systems, as well as stellar structure and evolution through the simultaneous long-term measurement of exoplanets and their host-stars.  It will enable us to completely characterize the planet-hosting stars through asteroseismology and to accurately measure stellar and planetary radii, masses and ages.



The Photodetector Array Camera and Spectrometer (PACS) is one of the three instruments aboard ESA's fourth cornerstone mission in the Horizon 2000+ project, the Herschel Space Observatory. Herschel is a space telescope observing in the Far-InfraRed and sub-millimeter wavelength region. The institute is one of the consortium members with a large participation in the Instrument Control Centre (ICC).

Herschel Space Observatory-PACS


Kepler is a space observatory launched by NASA to discover Earth-like planets orbiting other stars. The spacecraft, named for the Renaissance astronomer Johannes Kepler, was launched on March 7, 2009. Kepler's sole instrument is a photometer that continually monitors the brightness of over 145,000 main sequence stars in a fixed field of view. This data is transmitted to Earth, then analysed to detect periodic dimming caused by extrasolar planets that cross in front of their host star.



CoRoT is a French-led European space mission of ultra-high precision photometry dedicated to Stellar Seismology and Planet Finding launched in 2006. The scientific programme of the satellite consists of a Core Programme dedicated to the study of seismic properties of stars and to the detection of telluric planets, using long sequences of continuous observations of 150 days and a few shorter sequences. It is complemented by an Additional Programme dedicated to other scientific purposes.



EChO will provide an unprecedented view of the atmospheres of exoplanets transiting nearby stars. A mission dedicated to the differential technique of transit spectroscopy, EChO will build on the successes of the Hubble Space Telescope, Spitzer Space Telescope and ground-based optical telescopes. On the 19th february 2014, EChO has not been selected by ESA to be the third medium-class science mission. ESA selected the mission PLATO for implementation as part of its Cosmic Vision 2015–25 Programme. In the next few years, EChO may be resubmitted in the context of a future space mission selection.