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 16 stars included as λ Eri variables, five of them only suspected, and 13 combined with other types of variation.[5]

References

  1. ↑ Balona, L. A (1995). "Tests of the Pulsation and Starspot Models for the Periodic Be-Stars". Monthly Notices of the Royal Astronomical Society. 277 (4): 1547–1554. Bibcode:1995MNRAS.277.1547B. doi:10.1093/mnras/277.4.1547.
  2. ↑ 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.
  3. ↑ Carrier, F.; Burki, G.; Burnet, M. (2002). "Search for duplicity in periodic variable Be stars". Astronomy and Astrophysics. 385 (2): 488. Bibcode:2002A&A...385..488C. doi:10.1051/0004-6361:20020174.
  4. ↑ 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.
  5. ↑ Otero, S. A.; Watson, C.; Wils, P. "Variable Star Type Designations in the VSX". AAVSO Website. American Association of Variable Star Observers. Retrieved 19 July 2014.
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