Other research involvements

Below, I briefly describe previous research and minor projects that have led to publications.

Mission concept for in-situ characterization of biosignatures on Europa

In 2008—2009 I worked together with an international team of engineers, biologists, and physicists constructing a concept for a mission to Jupiter's moon Europa, involving everything from detailed evaluation of scientific instrumentation, mission sequences, basic spacecraft design, technology requirements, and cost estimations (Böttcher et al. 2009). The payload included an orbiter for investigating surface features and characterizing Europas internal structure, a lander for survey of the local environment, and a deployable cryobot for ice excavation and subsurface sampling in search for biosignatures. My main responsibility was the evaluation and conceptual design of a multispectral remote-sensing device envisioned for the orbiter.

Photometry of pulsating white dwarfs in cataclysmic variables

The mass-transfer onto a white dwarf (WD) in a cataclysmic variable (CV) system can occasionally excite non-radial pulsation modes in the WD, making it a so called ZZ Ceti star. In 2006 we performed photometric observations of five CVs with the Nordic Optical Telescope (NOT), and identified two new CV/ZZ Ceti hybrids (Nilsson et al. 2006). The results of our observations showed that the main pulsation frequencies agree with those found in previous CV/ZZ Ceti hybrids, and that data for the small sample of pulsating WDs in CV systems found so far, seems to indicate that the r-i color could be a good marker for the instability strip of this class of pulsating WDs.

Astronomical quantum optics and high-time resolution astrophysics

Future extremely large ground-based optical telescopes (ELTs), with apertures of around 40 m and light-collecting areas approaching 1000 m2, will enable measurements of photon-stream statistics and observations of astrophysical events on nanosecond time-scales. During 06/2004—06/2006 I participated in a concept study of an instrument on the planned European 100-m Overwhelmingly Large Telescope (now down-scaled to a 40-m Extremely Large Telescope), that can meet the required demands of rapid photon counting and handle extreme data rates (see, e.g., Barbieri et al. 2007). By using avalanche photodiode (APD) detectors in conjunction with digital hardware-correlators, we could demonstrate the advantages of real-time data reduction to statistical functions (e.g., 2:nd order correlation functions) for these demanding measurements, compared to traditional photometric methods, both in astronomical observations and laboratory settings (Nilsson 2005).