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High Mass Triple Systems: The Classical Cepheid Y Car

N. R. Evans·K. G. Carpenter·R. Robinson·F. Kienzle·A. E. Dekas
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Abstract

We have obtained an HST STIS ultraviolet high dispersion Echelle mode spectrum the binary companion of the double mode classical Cepheid Y Car. The velocity measured for the hot companion from this spectrum is very different from reasonable predictions for binary motion, implying that the companion is itself a short period binary. The measured velocity changed by 7 km/ s during the 4 days between two segments of the observation confirming this interpretation. We summarize "binary" Cepheids which are in fact members of triple system and find at least 44% are triples. The summary of information on Cepheids with orbits makes it likely that the fraction is under-estimated.

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N. R. Evans, K. G. Carpenter, R. Robinson, F. Kienzle, A. E. Dekas. 2005-04-07. High Mass Triple Systems: The Classical Cepheid Y Car. https://doi.org/10.1086/430458

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