Structure of Gravitationally Bound Stellar Groupings
Structure of Gravitationally Bound Stellar Groupings
Overview
- Gravitationally bound stellar groupings refer to clusters of stars bound by the gravitational pull of their combined mass.
- These groupings include binary star systems, multiple star systems, open star clusters, globular clusters and galaxies.
Binary and Multiple Star Systems
- Binary star systems consist of two stars orbiting around their common centre of mass.
- When more than two stars are involved, the system is called a multiple star system.
- These systems may reveal their nature by gravitational lensing, in which the gravity of the closer star bends the light of the more distant star.
Open Star Clusters
- An open star cluster, also known as a galactic cluster, is a grouping of tens to thousands of stars.
- These stars are gravitationally bound and were formed from the same giant molecular cloud.
- The most famous example of an open star cluster is the Pleiades or “Seven Sisters”.
Globular Clusters
- A globular cluster is a spherical collection of stars that orbits a galactic core.
- These clusters contain tens to hundreds of thousands of stars and are notably more tightly bound compared to open star clusters.
- Globular clusters can be found in halo regions around galaxies, suggesting they are older structures.
Galaxies
- A galaxy refers to a vast system consisting of billions of stars, interstellar gas, dust, and dark matter.
- A variety of galaxies exist, including spiral galaxies, elliptical galaxies and irregular galaxies.
- Our solar system resides in the Milky Way galaxy, which is a spiral galaxy.
- Some galaxies form clusters known as galaxy clusters.
Importance of Understanding Stellar Groupings
- The study of these groupings provides insight into stellar evolution, as stars within the same cluster are generally of similar ages.
- Observation and analysis of these groupings also provide crucial evidence for the Big Bang theory and offer perspective on the scale and structure of the cosmos.
- Technological advances continue to improve our understanding of these star groupings and how they form, evolve, and eventually dissipate.