A Lambda Eridani Variable is a class of
Be star
Be stars are a heterogeneous set of stars with B spectral types and emission lines. A narrower definition, sometimes referred to as ''classical Be stars'', is a non-supergiant B star whose spectrum has, or had at some time, one or more Balmer ...
s that show small amplitude variations of a few hundredths of a magnitude. The variations are highly regular with periods between 0.5 and 2.0 days, and they were initially described as periodic Be stars.
is an example and the prototype. This has been ascribed to non-radial pulsations, inhomogeneous rotating discs, or the rotation of the star itself.
These stars are rarely classified, or are classified incorrectly. The
General Catalogue of Variable Stars
The General Catalogue of Variable Stars (GCVS) is a list of variable stars in the Milky Way Galaxy. Its first edition, containing 10,820 stars, was published in 1948 by the Academy of Sciences of the USSR, edited by and Pavel Parenago. Second a ...
does not have a type for λ Eridani variables, only GCAS for
Gamma Cassiopeiae variables and
BE for non-GCAS Be star variables. λ Eridani itself is incorrectly listed as a
Beta Cephei variable.
The
AAVSO International Variable Star Index defines a LERI type of variability, with 51 stars included as λ Eri variables, 16 of them only suspected, and 32 combined with other types of variation.
References
{{Variable star topics
Star types