Multiplicity in 5 Msun Stars

TL;DR

This paper reviews multiwavelength observations of 5 Msun stars, revealing their binary and multiple star properties, mass ratios, and the prevalence of triple systems, offering insights into star formation processes.

Contribution

It highlights the importance of multiwavelength data in understanding the properties and formation of binary and multiple 5 Msun stars, including the high fraction of triples.

Findings

High fraction of triple systems among 5 Msun stars

Multiwavelength data enables detailed system characterization

X-ray observations identify young low-mass companions

Abstract

Multiwavelength opportunities have provided important new insights into the properties of binary/multiple 5 Msun stars. The combination of cool evolved primaries and hot secondaries in Cepheids (geriatric B stars) has yielded detailed information about the distribution of mass ratios. It has also provided a surprisingly high fraction of triple systems. Ground-based radial velocity orbits combined with satellite data from Hubble, FUSE, IUE, and Chandra can provide full information about the systems, including the masses. In particular, X-ray observations can identify low mass companions which are young enough to be physical companions. These multiwavelength observations provide important tests for star formation scenarios including diffenences between high and low mass results and differences between close and wide binaries.