misc:description | Rapid irregular variables (class: eruptive) having no apparent connection with diffuse nebulae and showing light changes of about 0.5 - 1.0 mag within several hours or days. There is no strict boundary between rapid irregular and Orion variables. If a rapid irregular star is observed in the region of a diffuse nebula, it is considered an Orion variable. To attribute a variable to this type (R.I.), it is necessary to take much care to be certain that its light changes are really not periodic.
Sub-types:
- Rapid irregular variables of the early spectral types, B-A or Ae;
- Rapid irregular variables of the intermediate and late spectral types, F-M and Fe-Me. |