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Absolute Properties Of The Pre-Main-Sequence Eclipsing Binary Star Np Persei, Claud H. Sandberg Lacy, Francis C. Fekel, Krešimir Pavlovski, Guillermo Torres, Matthew W. Muterspaugh

Information Systems and Engineering Management Research Publications

NP Per is a well-detached, 2.2 day eclipsing binary whose components are both pre-main-sequence stars that are still contracting toward the main-sequence phase of evolution. We report extensive photometric and spectroscopic observations with which we have determined their properties accurately. Their surface temperatures are quite different: 6420 ± 90 K for the larger F5 primary star and 4540 ± 160 K for the smaller K5e star. Their masses and radii are 1.3207 ± 0.0087 solar masses and 1.372 ± 0.013 solar radii for the primary, and 1.0456 ± 0.0046 solar masses and 1.229 ± 0.013 solar radii for the secondary. …