AS 381, CPD-57 2874

These two objects are also known to have high luminosities, but they reside slightly outside the classical B[e]SG domain in the near-IR diagram. AS 381 is a reported binary [64,65] consisting of a luminous B[e]SG and a K-type companion, which seems to (significantly) contribute to the total near-IR flux, hence altering the colors of the B[e]SG. The near-IR colors of CPD-57 2874 place it closer to the LBVs rather than to the B[e]SGs, although its H–K color is subject to large uncertainty. Its pronounced emission in CO, and in the [O I] and [Ca II] forbidden lines [58] speak against an LBV classification.

### (Hen 3-938), (MWC 342), (Hen 3-303), (CD-42 11721)

The rather low luminosities of these four objects and the closeness or even coincidence of their location with the HAeBe domain clearly requires further studies for an unambiguous classification. While Hen 3-938 and MWC 342 have to our knowledge not ye<sup>t</sup> been spectroscopically observed in

the K-band, the other two stars showed no evidence for CO band emission [39]. This renders their classification more difficult.

**Figure 8.** Near-IR diagrams as in Figure 6, showing the locations of the Galactic confirmed B[e]SGs (**top**) and B[e]SG candidates (**bottom**). The colors of the Galactic objects have been corrected for interstellar extinction (Table 9).
