Exoplanets orbiting non-eclipsing binaries: filling the gap in exoplanet detection using 0.5m class telescopes and Gaia DR3 non-single star data

As many as 85% of stars are members of binary or higher order systems. The search for exoplanets orbiting binary stars has previously concentrated on eclipsing binaries due to their relative ease of detection. Given that the difference between eclipsing and non-eclipsing binaries is essentially geometric, it is likely that there will be at least as many exoplanets orbiting non-eclipsing binaries as there are orbiting eclipsing binaries, implying a large cohort of exoplanets are being overlooked. New data sources such as the Gaia DR3 non-single star tables provide enhanced opportunities for the identification of non-eclipsing binaries and the investigation of their exoplanetary systems. This project has assessed the effectiveness of 0.5m class telescopes in the detection of exoplanets in orbit around non-eclipsing binaries. This has been achieved by generating targets for observation using the Open University’s PIRATE telescope, by cross-referencing known exoplanets with binary star data taken from the Gaia DR3 non-single star tables. Seven targets were selected and observed over a six week period, two of which (TOI-4463A and WASP-2A) were also submitted to ExoClock, a project aimed at supporting the upcoming ESA ARIEL mission. A further five targets (GSC 03467-0030, HD 114623, HD 132406, Kepler-16 and Kepler-1697) were subjected to longer term observation and analysis using AstroImageJ. The effectiveness of 0.5m class telescopes in producing light curves for use by ExoClock is demonstrated, as is the feasibility of using such telescopes for the detection of both circumbinary (e.g. Kepler-16b) and circumstellar (e.g. WASP-2Ab) exoplanets orbiting non-eclipsing binaries. The overall conclusion is that the limiting factors are the geometry of the system, which favours inclined planetary orbits, and the period of observation, which needs to be long enough to capture the transit, rather than the telescope itself.