Stellar classification
type: Concept
related: A stars

Ae stars
type: Concept
broader: A stars

Stellar spectral types
type: Concept
narrower: A stars

A dwarf stars
type: Concept
broader: A stars

Am stars
type: Concept
broader: A stars

A giant stars
type: Concept
broader: A stars

Early-type stars
type: Concept
narrower: A stars

A stars
type: Concept
contributor: AAS Frey.Katie
modified: 2020-10-26T18:21:50.162Z
modified: 2020-10-26T18:21:38.213Z
alternative label: A type stars
alternative label: Type A stars
alternative label: A-type stars
alternative label: Class A stars
broader: Early-type stars
broader: Stellar spectral types
definition: A star whose spectrum shows strong hydrogen Balmer lines accompanied by many faint to moderately strong metallic lines. In contrast to B and O stars, the lines of He I and He II are absent. Their surface temperature ranges from 7,500 to 10,000 K. The main metallic lines seen in A-type stars are those of Fe I and Fe II, Cr I and II, Ti I and II, and account for about two-thirds of all lines. Some famous examples of A star are Sirius, Deneb, Altair, and Vega. Also known as A-type star.
narrower: A subdwarf stars
narrower: Am stars
narrower: A subgiant stars
narrower: A giant stars
narrower: Ae stars
narrower: A dwarf stars
narrower: A supergiant stars
narrower: Ap stars
related: Stellar classification

Ap stars
type: Concept
broader: A stars

A subdwarf stars
type: Concept
broader: A stars

A subgiant stars
type: Concept
broader: A stars

A supergiant stars
type: Concept
broader: A stars