A Lambda Eridani Variable is a class of Be stars 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.[1]Lambda Eridani is an example and the prototype. This has been ascribed to non-radial pulsations, inhomogeneous rotating discs, or the rotation of the star itself.[2][3]
These stars are rarely classified, or are classified incorrectly. The General Catalogue of Variable Stars 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.[4] 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.[5][6]
^Jerzykiewicz, M.; Kopacki, G.; Pigulski, A.; Kołaczkowski, Z.; Kim, S.-L. (2011). "A CCD Search for Variable Stars of Spectral Type B in the Northern Hemisphere Open Clusters. VIII. NGC 6834". Acta Astronomica. 61 (3): 247–273. arXiv:1110.4064. Bibcode:2011AcA....61..247J.
^Samus, N. N.; Durlevich, O. V.; et al. (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)". VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S. 1. Bibcode:2009yCat....102025S.