Intergalactic star
Encyclopedia
Discovery
The common belief that stars exist only in galaxies was disproven in 1997 with the discovery of intergalactic stars. The first to be discovered were in the Virgo clusterVirgo Cluster
The Virgo Cluster is a cluster of galaxies whose center is 53.8 ± 0.3 Mly away in the constellation Virgo. Comprising approximately 1300 member galaxies, the cluster forms the heart of the larger Local Supercluster, of which the Local Group is an outlying member...
of galaxies, where some one trillion are now surmised to exist.
Formation
Although the way in which these stars form is still a mystery, the most common theory is that the collision of two or more galaxies can toss certain stars out into the vast regions of empty space.
Observation history
In 1997, the Hubble telescope discovered a large number of intergalactic stars in the Virgo cluster of galaxies. Later in the 1990s scientists discovered another group of intergalactic stars in the Fornax clusterFornax Cluster
At a distance of approximately 62.0 Mly , the Fornax Cluster is the second richest cluster of galaxies within 100 million light-years, although it is much smaller than the Virgo Cluster. It lies primarily in the constellation Fornax, and may be associated with the nearby Eridanus Group...
of galaxies.
Mass
Although the precise mass of these stars cannot be known, it is estimated that they take up 10 percent of the mass of the Virgo cluster of galaxies. This means that most likely these stars have a larger mass than any particular one of the twenty-five hundred galaxies that form the Virgo cluster.Location
The first intergalactic stars were discovered in the Virgo clusterVirgo Cluster
The Virgo Cluster is a cluster of galaxies whose center is 53.8 ± 0.3 Mly away in the constellation Virgo. Comprising approximately 1300 member galaxies, the cluster forms the heart of the larger Local Supercluster, of which the Local Group is an outlying member...
of galaxies. These stars form a massive group approximately 300,000 light years away from the nearest galaxy.
See also
- Stars
- Virgo clusterVirgo ClusterThe Virgo Cluster is a cluster of galaxies whose center is 53.8 ± 0.3 Mly away in the constellation Virgo. Comprising approximately 1300 member galaxies, the cluster forms the heart of the larger Local Supercluster, of which the Local Group is an outlying member...
- Intergalactic dustIntergalactic dustIntergalactic dust is cosmic dust in between galaxies in intergalactic space. Evidence for intergalactic dust has been suggested as early as 1949, and study of it grew throughout the late 20th century. There are large variations in the distribution of intergalactic dust...
- HE 0437-5439HE 0437-5439HE 0437-5439 is a massive, unbound hypervelocity star , also called HVS3. It is a main sequence B-type star located in the Dorado constellation. It was discovered in 2005 with the Kueyen 8.2 meter telescope, which is part of the European Southern Observatory's Very Large Telescope array. HE...
- Blue stragglerBlue stragglerBlue stragglers are main sequence stars in open or globular clusters that are more luminous and bluer than stars at the main sequence turn-off point for the cluster. Blue stragglers were first discovered by Allan Sandage in 1953 while performing photometry of the stars in the globular cluster M3...
- Stellar kinematicsStellar kinematicsStellar kinematics is the study of the movement of stars without needing to understand how they acquired their motion. This differs from stellar dynamics, which takes into account gravitational effects...