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HS0705+6700 (also identified as V470 Cam) is a short period (2.3 h) post-common envelope detached eclipsing sdB binary system which exhibits transit time variations (TTVs) of a cyclical nature. We report a further 25 timings of light minima and show that our new TTVs support and extend this cyclical pattern to 1.6 periods. We examine possible causes of the observed TTVs and confirm that the presence of a third, and possibly a fourth, body could provide an elegant explanation of these cyclical variations. However other non-circumbinary mechanisms, e.g. Applegate magnetic dynamo effects, will remain possible contenders until sufficient data has been accumulated to demonstrate that the periodicity of the TTVs is time independent. A further 27 eclipse timings recorded between 2014 October and 2015 April are reported in the Addendum. These new timings occurred 0.00012 days (~10s) later than anticipated by our circumbinary model. Two possible explanations are offered.

A method of daytime collimation of a Cassegrain-type reflecting telescope is described, which uses a circular target aligned on the optical axis of the primary mirror. Basic construction details are given for making a suitable target and a procedure is outlined for collimating both Schmidt–Cassegrain and Ritchey–Chrétien telescopes.

Four low resolution (R~1000) spectra were obtained of the RV Tauri-type variable AC Her during its rise from a deep minimum in July 2014. These show changes in spectral type and Balmer line equivalent width as the star brightened, consistent with earlier observations.