Yes, astronomers have indeed observed objects in the universe that are adrift between galaxies. These objects are commonly referred to as intergalactic or intracluster stars.
Intergalactic stars are stars that are not bound to any specific galaxy but instead exist in the vast regions between galaxies. These stars are thought to have been expelled from their original galaxies due to gravitational interactions, such as galactic mergers or tidal forces. They become "stray" or "rogue" stars, wandering through the intergalactic space.
The discovery of intergalactic stars has been challenging because they are relatively faint and widely dispersed. However, recent studies using advanced telescopes and observational techniques have managed to detect and study these objects. For example, in 2017, a team of astronomers reported the discovery of a population of intergalactic stars in the Coma Cluster, a massive cluster of galaxies. These stars were found to be moving between galaxies, lacking any association with a particular galaxy.
Additionally, there have been observations of other intergalactic objects such as intergalactic planetary nebulae, intergalactic supernovae, and even intergalactic globular clusters. These objects provide further evidence of the existence of stellar populations adrift in the vast cosmic voids.
Studying intergalactic stars and other intergalactic objects can provide valuable insights into the dynamics of galaxy clusters, the processes of galaxy formation and evolution, and the interplay between galaxies and the intergalactic medium.