Chemically peculiar stars
type: Concept
narrower: Helium-weak stars

Helium-weak stars
type: Concept
broader: Chemically peculiar stars
alternative label: Helium-poor stars
alternative label: Helium weak stars
alternative label: He-weak stars
alternative label: CP4
alternative label: Helium poor stars
modified: 2020-12-16T20:32:19.876Z
modified: 2020-11-09T16:17:33.394Z
contributor: AAS Frey.Katie Admin
contributor: AAS Frey.Katie
definition: Chemically peculiar stars with very weak helium lines. Examples include 3 Sco, HD 176582, HD 217833, HR 2949, and HD 21699. The He-weak stars do not form a homogeneous group. Some of them display intense Si, or Ti and Sr lines, and are considered a hot extension of the magnetic Ap/Bp stars. Others show overabundances of P and Ga, typically noted for HgMn stars. The star HD 139160 belongs to the non-magnetic subgroup of He-weak stars.
narrower: BW stars

BW stars
type: Concept
broader: Helium-weak stars