  As Be stars are restricted to luminosity classes III-V, but early B-type
stars are believed to evolve into supergiants, it is to be expected that the Be
phenomenon disappears at some point in the evolution of a moderately massive
star, before it reaches the supergiant phase. As a first stage in an attempt to
determine the physical reasons of this cessation, a search of the literature
has provided a number of candidates to be Be stars with luminosity classes Ib
or II. Spectroscopy has been obtained for candidates in a number of open
clusters and associations, as well as several other bright stars in those
clusters. Among the objects observed, HD207329 is the best candidate to be a
high-luminosity Be star, as it appears like a fast-rotating supergiant with
double-peaked emission lines. The lines of HD229059, in Berkeley 87, also
appear morphologically similar to those of Be stars, but there are reasons to
suspect that this object is an interacting binary. At slightly lower
luminosities, LS I +56 92 (B4II) and HD333452 (O9II), also appear as
intrinsically luminous Be stars. Two Be stars in NGC 6913, HD229221 and
HD229239, appear to have rather higher intrinsic magnitudes than their spectral
type (B0.2III in both cases) would indicate, being as luminous as luminosity
class II objects in the same cluster. HD344863, in NGC 6823, is also a rather
early Be star of moderately high luminosity. The search shows that, though
high-luminosity Be stars do exist, they are scarce and, perhaps surprisingly,
tend to have early spectral types
