Professor of Experimental astrophysics
E-mail: keller@strw.leidenuniv.nl
Telephone: +31 71 527 8427
ORCID: Christoph Keller
Google Scholar: Christoph Keller
Office number: HL 1126
Christoph Keller leads the experimental astrophysics group at Leiden Observatory. His group is a world leader in the development of high-accuracy polarimetric instrumentation for astronomy and environmental sensing. The group achieves order-of-magnitude performance gains by inventing novel optical techniques or innovatively combining optical components that are already available on the market.
The group develops high-contrast imaging instrumentation for the world’s current and future largest telescopes like the Very Large Telescope and the Extremely Large Telescope. Instruments like ExPo, SPHERE-ZIMPOL and EPICS combine high-sensitivity polarimetry with adaptive optics and coronagraphy to directly detect exoplanets around bright stars. Such direct observations consecutively permit the characterization of exoplanetary atmospheres through accurate spectropolarimetry. These developments also find their way into the latest space instruments for climate science.
The group is also heavily involved in polarimetric instrumentation to characterize our own atmosphere. The invention of the spectral polarization modulation principle by Snik and Keller led to the development of the SPEX satellite instrument and the groundSPEX and iSPEX instruments that now provide new data on atmospheric particles from the ground.
Keller authored or co-authored more than 350 publications. His SPIE Field Guide to Astronomical Instrumentation was among the 16 SPIE Press bestsellers in 2016.
Papers and Conference proceedings
For a comprehensive and up-to-date list of publications of Christoph Keller please proceed to the astrophysics data system.
A selection of previous publications can be found here:
Keller C.U., Navarro R., Brandl B.R. 2015. Field Guide to Astronomical Instrumentation. SPIE Press
Keller C.U., Korkiakoski V., Doelman N., Fraanje R., Andrei R., Verhaegen M. 2012. Extremely fast focal-plane wavefront sensing for extreme adaptive optics. SPIE 8447, 844721
Korkiakoski V., Doelman N., Codona J., Kenworthy M., Otten G., Keller C.U. 2013. Calibrating a high-resolution wavefront corrector with a static focal-plane camera. Applied Optics 52, 7554
van Werkhoven T.I.M., Antonello J., Truong H.H., Verhaegen M., Gerritsen H.C., Keller C.U. 2014. Snapshot coherence-gated direct wavefront sensing for multi-photon microscopy. Optics Express 22, 9715
Ren D., Keller C., Plymate C. 2009. An IFU for diffraction-limited 3D spectroscopic imaging: laboratory and on-site tests. SPIE 7438, 743818
Rodenhuis M., Canovas H., Jeffers S.V., de Juan Ovelar M., Min M., Homs L., Keller C.U. 2012. The Extreme Polarimeter: design, performance, first results and upgrades. SPIE 8446, 84469I
Keller C.U. & 12 coauthors 2010. EPOL: the exoplanet polarimeter for EPICS at the E-ELT. SPIE 7735, 77356G
Brogi M., Keller C.U., de Juan Ovelar M., Kenworthy M.A., de Kok R.J., Min M., Snellen I.A.G. 2012. Evidence for the disintegration of KIC 12557548b. A&A 545, L5
Jeffers S.V., Min M., Waters L.B.F.M., Canovas H., Rodenhuis M., de Juan Ovelar M., Chies-Santos A.L., Keller C.U. 2012. Direct imaging of a massive dust cloud around R Coronae Borealis, A&A 539, A56
Snik F., Karalidi T., Keller C.U. 2009. Spectral modulation for full linear polarimetry. Applied Optics 48, 1337