*4.3. Beyond the Local Group*

Not much is known ye<sup>t</sup> about the B[e]SG population beyond the Local Group. Most promising for dedicated searches are the nearby large spiral galaxies M81, M101, and NGC 2403, for which pioneering ground-based surveys have been conducted already in the 1980s and 1990s [146–149] and which are nowadays extended to fainter objects thanks to the capabilities of the Hubble Space Telescope (e.g., [150]). Spectroscopic follow-up investigations revealed a number of variable luminous objects [151–155], but only in one of these galaxies, M81, three B[e]SG candidates have been found so far [156]. They all display the typical B[e] features in their optical spectra, but without complementary information about the presence of (warm) circumstellar dust, their classification remains preliminary. These objects will certainly not remain the only of their kind, because the search for more candidates has just begun.

The B[e]SG candidates in M81 are listed in Table 8. For lack of proper SIMBAD identifiers for these objects, the table contains the star ID [156] along with the coordinates and, where available, the V band magnitudes.


**Table 8.** Candidate B[e]SGs in M81.

In the past few years, additional surveys have been performed, using large ground-based facilities (e.g., [157]) and space telescopes (e.g., [158,159]). These surveys were aimed at revealing the luminous and variable massive star populations of other galaxies even further away. They provide an excellent basis for follow-up spectroscopic studies to classify their massive star content, so that many more LBV candidates and B[e]SGs may be found in the (near) future. In addition, the Local Group galaxies still need to be explored in more detail, in particular those galaxies that were already found to possess (even though in very small numbers) LBV candidates [95] that are awaiting their proper classifications. The upcoming era of the Extreme Large Telescope (ELT) promises to become particularly fruitful. The next generation of high-sensitivity instruments combined with the large collecting area of the telescope will facilitate ground-based spectroscopic observations of faint objects with very high spatial resolution.
