Unclassified B[e] stars
A star showing the B[e] phenomenon appears in the group of unclassified B[e]
stars, if its evolutionary phase is unknown. Reasons for failures in
classifying stars are often the missing information on reliable stellar
parameters and on the distances towards the stars. Especially the distance issue
renders it notorically difficult to determine proper stellar luminosities, and
this is why, for example, there exists a sub-sample of the unclassified B[e] stars
which we call B[e] supergiant candidates
, because these stars
show indications of both a young, pre-main sequence (Herbig)
nature as well as an evolved, B[e] supergiant nature, but their unclear luminosities
makes a proper assignment to the group of B[e] supergiants at least very difficult.
Some recent results on
individual stars in this category can be found here
Our aim in studying the unclassified B[e] stars is to find their most probable evolutionary stage.
We are aware of the fact that some stars might be in binaries and that effects like
binary interaction could be the reason for the B[e] phenomenon, or that especially
close binaries might have merged, thereby leaving us with a remnant that can not
be described by the stellar evolution theory of single stars. Nevertheless, detailed
studies on each individual object are certainly necessary before we can draw any
reliable conclusion about the current status and past evolution of these stars.
We therefore devoted substantial time and effort to our studies of a few individual
objects. Brief summaries of our results can be found below.
Recent Results on Selected Objects
- Hen 2-90 - a compact planetary nebula
- HD50138 - a star at the end of its main-sequence evolution
Last modified 17.2.2011