Double white dwarfs

AM CVn stars
Ultra-compact X-ray

Black hole binaries
SN Ia progenitors
Gravitational waves
LISA wiki (verification

My thesis


I'm involved in a number of surveys.

The Galactic Bulge Survey

The Galactic Bulge Survey (GBS) is a combined X-ray (Chandra) and optical (Blanco Mosaic) survey of fields in the Galactic Bulge, just above the dust layer, in order to optimally match optical and X-ray depth (with optical detection of the majority of sources) while still surveying the X-ray population near the Galactic Center. For more information on the GBS click here The first overview paper has been published Jonker et al. 2011

The European Galactic Plane Surveys

The European Galactic Plane Surveys (EGAPS) are a collection of optical surveys, together covering the full Galactic plane (10 x 360 degrees) in four optical bands (u', g', r', i') as well as narrow-band Halpha and HeI. The EGAPS website unfortunately does not contain much information yet.

The RApid Temporal Survey (RATS)

The The RApid Temporal Survey (RATS) is a survey aimes at finding short period (less than ~80 min) variable stars. For more information see the RATS homepage


OmegaWhite is a 400 square degrees survey for short period variables, using the OmegaCam imager on the VST. For more information see the OmegaWhite website

The ESO Supernova Ia Progenitor surveY (SPY)

This is a survey (PI Ralf Napiwotzki) in which we have looked at about 1000 white dwarfs to search for radial velocity variations that indicate the white dwarfs are part of a double white dwarf binary. The surveys is currently finished, but we are very busy with follow-up observations of the about 100 double white dwarfs that have been found.

The Faint Sky Variability Survey

The Faint Sky Variability Survey (FSVS) is a wide field survey of ~23 square degrees in which colour and variability information (photometric as well as astrometric) is obtained for objects brighter than V = 24. The first part of the survey has now finished, the fields will only be re-observed yearly to improve the astrometry. The data has been reduced and follow-up of interesting sources in under way.

For more information, see the FSVS paper I and FSVS Paper II