Binarity among Cepheids in the Magellanic Clouds

TL;DR

This paper reports the detection of spectroscopic binarity in a Magellanic Cloud Cepheid, compiles a list of known binaries, and discusses the apparent deficiency of such systems compared to the Milky Way, suggesting observational biases or intrinsic differences.

Contribution

It provides the first spectroscopic binary detection among Magellanic Cepheids and compiles a comprehensive list of known binaries in these galaxies.

Findings

Detection of binarity in HV914 from radial velocity data

Compilation of known Cepheid binaries in the Magellanic Clouds

Identification of a deficiency of known binaries compared to the Milky Way

Abstract

Spectroscopic binarity of the Cepheid variable HV914 in the Large Magellanic Cloud is pointed out from the published radial velocity observational data. The list of known binaries among Cepheid type variable stars in the Magellanic Clouds is published in tabular form. The census indicates a serious deficiency of Cepheids with known companions as compared with their Galactic counterparts, whose implications are also discussed. A particular amplitude ratio (A_{V_{rad}}/A_B) of individual Magellanic Cepheids is studied in order to select promising candidates of spectroscopic binaries worthy of thorough radial velocity studies.