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We describe the development, construction, data analysis, initial calibration, and first results of the Leicester dual-beam imaging polarimeter (LE2Pol), an inexpensive dual-beam optical imaging polarimeter. LE2Pol is designed for a 20-inch telescope at the observatory of the University of Leicester, but can also be used as a visiting instrument on a wide range of small telescopes (≲1 m). We show how simple imaging polarimeters on small telescopes can be used to provide useful scientific and educational data at low cost.

We performed a spectroscopic and photometric analysis to study new eruptions in two luminous blue variables (LBVs) in the Magellanic Clouds. We detected a strong new eruption in the LBV R40 that reachedV~ 9.2 in 2016, which is around 1.3 mag brighter than the minimum registered in 1985. During this new eruption, the star changed from an A-type to a late F-type spectrum. Based on photometric and spectroscopic empirical calibrations and synthetic spectral modeling, we determine that R 40 reachedTeff= 5800–6300 K during this new eruption. This object is thereby probably one of the coolest identified LBVs. We could also identify an enrichment of nitrogen andr- ands-process elements. We detected a weak eruption in the LBV R 110 with a maximum ofV~ 9.9 mag in 2011, that is, around 1.0 mag brighter than in the quiescent phase. On the other hand, this new eruption is about 0.2 mag fainter than the first eruption detected in 1990, but the temperature did not decrease below 8500 K.Spitzerspectra show indications of cool dust in the circumstellar environment of both stars, but no hot or warm dust was present, except by the probable presence of PAHs in R 110. We also discuss a possible post-red supergiant nature for both stars.