Are there wandering stars in the Universe? There are billions of galaxies scattered across the Universe that we live in. Some of these galaxies exist in giant clusters of hundreds or thousands of them. In these giant clusters of galaxies, exist billions or trillions of stars, planets, and other celestial bodies. However, some of these stars are not gravitationally tied to any particular galaxy. Instead, they wander from one galaxy to another just like the rogue planets moving from one planetary system to another. Astronomers have always wondered how stars were able to spread across the cluster of galaxies.
To answer this question, several scientists get to work and came up with different competing theories to explain their individual opinions. However, some of these theories suggest that the stars were stripped from a cluster of galaxies, while another theory suggests that wandering stars might be present while the clusters were forming several billions of years ago. Other scientists assume that they were tossed around after mergers of galaxies occur billions of years in the past.
How Astronomers Conducted the New Survey about Wandering Stars
A team of Scientists from Yonsei University, Seoul, and the Universe of California, Davis, used NASA’s Hubble Space Telescope to conduct an infrared study of distant galaxy clusters. From their observations, they learned that wandering stars have been traveling around the cluster for billions of years. these recent observations countered the previous theories that suggest that the rogue stars were stripped from their home galaxies.
The team of scientists that participated in the survey included Hyungjin Joo, a Ph.D. candidate alongside the Yonsei Observable Universe Group (YOUNG) at Yonsei University. Myungkook James Jee, the leader of the YOUNG group and an LSST Fellow at the University of California Davis also participated in the survey. The team commenced with the survey by comparing the total light of the galaxy cluster and how it decreased fast with an increase in redshift.
During a recent infrared observation, the team used NASA’s Hubble Space Telescope to study the Intracluster light. This new survey carried out by Hubble has it that these stars have been traveling around galaxies for billions of years and they are not caused by the most recent dynamical activity taking place within a galaxy cluster.
Some scientists previously suggest that dynamic activities happening in a galaxy cluster can strip stars from regular galaxies. However, the new Hubble observation counters this previously held assumption. Hubble’s recent observation focused on studying 10 galaxy clusters located about 10 billion light years away.
Scientists obtained the necessary measurement of the study from space as the intracluster light is about 10,000 times dimmer than Earth’s night sky. From this observation in which Hubble looked over billions of years back in time, scientists learned that the fraction of the intracluster light relative entire light in the cluster has remained constant. The researchers were fascinated with the outcome of the observation.
“This means that these stars were already homeless in the early stages of the cluster’s formation,” said James Jee of Yonsei University in Seoul, South Korea, who participated in the study.
The observation enabled scientists to learn that stars can be scattered whenever a galaxy travels across gaseous material that exists in space between other galaxies while orbiting the center of the cluster. The movement process makes gas and dust to be eliminated from a particular galaxy. James Jee used the recent Hubble data to realize that the movement of the galaxy around its cluster is the basic cause of intracluster star production.
“We don’t exactly know what made them homeless. Current theories cannot explain our results, but somehow they were produced in large quantities in the early universe,” said Jee. “In their early formative years, galaxies might have been pretty small and they bled stars pretty easily because of a weaker gravitational grasp.”
Another scientist that participated in the study also shared his opinion about wandering stars.
“If we figure out the origin of intracluster stars, it will help us understand the assembly history of an entire galaxy cluster, and they can serve as visible tracers of dark matter enveloping the cluster,” said Hyungjin Joo of Yonsei University, the first author of the paper. Dark matter is the invisible scaffolding of the universe, which holds galaxies, and clusters of galaxies, together. dark matter
Jee and his colleague published the latest findings in Journal Nature.
What Scientists learned from this survey about wandering stars
Studying wandering stars has remained a major goal of many scientists across the world. The recent data provided by Hubble enabled scientists that participated in the study to learn that if wandering stars were created via the movement of a galaxy around a cluster of galaxies, then they would not have all the time to spread across the whole gravitational field of the cluster. Hence, making it impossible to trace the distribution of the cluster’s dark matter.
However, if the stars were created during the early years of the cluster, they will have enough time to scatter throughout the cluster. This new observation will enable astronomers to come up with new ways to map out dark matter distribution across the cluster using rogue stars. Although this method of mapping is still new and unique, it still complements the traditional technique of mapping dark matter by estimating how the entire cluster warps light from background objects through a process known as gravitational lensing.
How Intracluster Light is Opening Doors for more astronomical Discoveries
Intracluster light has remained hidden from astronomers for centuries. However, in 1951, Astronomer Fritz Zwicky discovered the first intracluster light in the Coma cluster of galaxies. The astronomer used his modest 18-inch telescope to observe the Coma cluster with about 1,000 galaxies. This cluster of galaxies is one of the nearest clusters to Earth located about 330 million light years away.
In recent times, scientists rely on studying Intracluster light using more sophisticated telescopes such as the Hubble Space Telescope and the most recent NASA’s James Webb Space Telescope. Although Hubble is powerful enough to detect these Intracluster lights from billions of light years away, the Webb is sophisticated enough to get a more detailed insight into the existence of a particular region of space. In fact, scientists are hoping that Webb will be able to solve several mysteries of deep space using data that will be obtained from intracluster stars in deep parts of the Cosmos.
This latest discovery about wandering stars has enabled scientists to think differently about their existence in the cluster of galaxies. With the assistance of NASA’s James Webb Space Telescope, scientists will make more fascinating discoveries and unveil more mysteries about intracluster lights reaching us from billions of light years away. What do you think about this fascinating discovery?