The Strange Evolution of the Large Magellanic Cloud Cepheid OGLE-LMC-CEP1812

Creator(s)

Hilding R. Neilson, University of Toronto
Robert G. Izzard, University of Cambridge
Nobert Langer, University Bonn
Richard Ignace, East Tennessee State UniversityFollow

Document Type

Article

Publication Date

9-1-2015

Description

Classical Cepheids are key probes of both stellar astrophysics and cosmology as standard candles and pulsating variable stars. It is important to understand Cepheids in unprecedented detail in preparation for upcoming Gaia, James Webb Space Telescope (JWST) and extremely-large telescope observations. Cepheid eclipsing binary stars are ideal tools for achieving this goal, however there are currently only three known systems. One of those systems, OGLE-LMC-CEP1812, raises new questions about the evolution of classical Cepheids because of an apparent age discrepancy between the Cepheid and its red giant companion. We show that the Cepheid component is actually the product of a stellar merger of two main sequence stars that has since evolved across the Hertzsprung gap of the HR diagram. This post-merger product appears younger than the companion, hence the apparent age discrepancy is resolved. We discuss this idea and consequences for understanding Cepheid evolution.

Copyright Statement

Reproduced with permission from Astronomy & Astrophysics, © 2015 ESO

Citation Information

Neilson, Hilding R.; Izzard, Robert G.; Langer, Nobert; and Ignace, Richard. 2015. The Strange Evolution of the Large Magellanic Cloud Cepheid OGLE-LMC-CEP1812. Astronomy & Astrophysics. Vol.581(A&A). L1. https://doi.org/10.1051/0004-6361/201526716 ISSN: 1432-0746