We investigated 12 unclassified B[e] stars or candidates, 8 from the Galaxy, 2 from the Large Magellanic Cloud (LMC), and 2 from the Small Magellanic Cloud (SMC). Based on the analysis of high-resolution spectroscopic (FEROS) and photometric data, we confirmed the presence of the B[e] phenomenon for all objects of our sample, except for one (IRAS 07455-3143). We derived their effective temperature, spectral type, luminosity class, interstellar extinction and, using the distances from Gaia DR2, we obtained their bolometric magnitude, luminosity, and radius. Modelling of the forbidden lines present in the FEROS spectra revealed information about the kinematics and geometry of the circumstellar medium of these objects. In addition, we analysed the light curves of four stars, finding their most probable periods. The evolutionary stage of 11 stars of our sample is suggested from their position on the HR diagram, taking into account evolutionary tracks of stars with solar, LMC, and SMC metallicities. As results, we identified B and B[e] supergiants, B[e] stars probably at the main sequence or close to its end, post-AGB and HAeB[e] candidates, and A[e] stars in the main sequence or in the pre-main sequence. However, our most remarkable results are the identification of the third A[e] supergiant (ARDB 54, the first one in the LMC), and of an ‘LBV impostor’ in the SMC (LHA 115-N82).

The Transneptunian Automated Occultation Survey (TAOS II) is a blind occultation survey with the aim of measuring the size distribution of Trans-Neptunian Objects with diameters in the range of 0.3 ≲ D ≲ 30 km. TAOS II will observe as many as 10,000 stars at a cadence of 20 Hz with all three telescopes simultaneously. This will produce up to ∼20 billion photometric measurements per night, and as many as ∼6 trillion measurements per year, corresponding to over 70 million individual light curves. A very fast analysis pipeline for event detection and characterization is needed to handle this massive data set. The pipeline should be capable of real-time detection of events (within 24 hours of observations) for follow-up observations of any occultations by larger TNOs. In addition, the pipeline should be fast and scalable for large simulations where simulated events are added to the observed light curves to measure detection efficiency and biases in event characterization. Finally, the pipeline should provide estimates of the size of and distance to any occulting objects, including those with non-spherical shapes. This paper describes a new data analysis pipeline for the detection and characterization of occultation events.

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 reachedT_eff= 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.

We present speckle interferometric measurements of binary stars performed during February and April of 2011 with the 1.5 m telescope and during July and November of 2011 with the 2.1 m telescope of the Observatorio Astronómico Nacional, San Pedro Mártir, México, focusing on objects from the Washington Double Star Catalog with separations less than 1″. Among these objects, we have been interested in performing a follow-up observation of new double stars discovered by Hipparcos. For these observations we developed a new detector, which is a combination of CCD Watec 120N with a third generation image intensifier. This image intensifier allows us to perform near-infrared speckle interferometric observations for the first time. In this paper we report 761 astrometric measurements of 478 pairs, with angular separations ranging from 0$${^{\prime\prime}_{.}}$$09 to 2$${^{\prime\prime}_{.}}$$61. We found that 722 of our measured separations are smaller than 1″. We estimated a mean error in separation of 16 mas and 1.29° in position angle. In order to overcome the usual 180° ambiguity inherent to speckle measurements, we created a shift-and-add reconstructed image of each source, to establish the true quadrant of the secondary star. We confirmed 40 double stars discovered by Hipparcos and found 4 field stars resolved as interferometric pairs for the first time, with separations smaller than 0$${^{\prime\prime}_{.}}$$60.

Exact ray tracing is the fundamental tool of geometric optics, it constitutes the foundation on which aberration theory and, therefore, optical design is based. We present the KrakenOS, a Python library focused on the accuracy of ray tracing and the generation of systems composed by optical surfaces with arbitrary shapes and orientations, as well as a compendium of practical examples for the use of our library. We describe a series of quality tests to compare the results obtained from ray tracing with KrakenOS with respect to those obtained with the commercial software Zemax. Among the performance computations, we include the final intersection coordinates with optical surfaces, the resulting director cosines, the calculation of surface-to-surface length of the optical path, the energy of the transmitted and reflected resulting rays, Zernike standard coefficients from wavefront fitting, and a comparison of the resulting intersection coordinates with a larger optical system. The difference between our results and those of Zemax is of the order of 9.0 × ^{10  −  8} mm, demonstrating that KrakenOS can be used in industrial or scientific work with high precision requirements for simple and very complex optical configurations.