Britannica
Sources used in this answer
What types of variable stars are common in globular clusters?
Created from Britannica articles
using AI.
AI can make mistakes, so verify using Britannica articles.
Star cluster
Centre of star cluster 47 Tucanae (NGC 104), showing the colours of various stars.
Most of the brightest stars are older yellow stars, but a few young blue stars are also visible. This picture is a composite of three images taken by the Hubble Space Telescope.
In globular clusters, the most common type of variable star is the RR Lyrae variable, which accounts for approximately 90 percent of the roughly 2,000 variable stars identified in examined clusters. These stars are characterized by regular variations in their intrinsic brightness and are located in a specific region of the colour-magnitude diagram known as the RR Lyrae gap, situated near the blue end of the horizontal branch.123
Other types of variable stars found in globular clusters include:
- Population II Cepheids12
- RV Tauri stars12
- U Geminorum stars12
- Mira stars12
- Eclipsing binaries12
- Novas12