# The study of unclassified B[e] stars and candidates in the Galaxy and Magellanic Clouds

## TL;DR

This study analyzes 12 unclassified B[e] stars across the Galaxy and Magellanic Clouds, confirming their B[e] phenomenon, deriving stellar parameters, and identifying their evolutionary stages and unique objects like an A[e] supergiant and an LBV impostor.

## Contribution

It provides detailed spectroscopic and photometric analysis of unclassified B[e] stars, revealing their nature, evolutionary stages, and discovering new rare objects.

## Key findings

- Confirmed B[e] phenomenon in all but one star.
- Derived stellar parameters and evolutionary stages.
- Discovered an A[e] supergiant in the LMC and an LBV impostor in the SMC.

## Abstract

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. Modeling 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 analyzed 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).