An international team of astronomers has discovered a new type of star system thanks to data from the Hubble Space Telescope.
The star systems, which experts say look like “blue spots” when viewed through a telescope lens and are the size of small dwarf galaxies, are not galaxies at all and only exist in isolation.
The University of Arizona released a statement that said: “Stellar structures are thought to be created when galaxies collide with hot gas in a process that could be compared to tipping over in a swimming pool.”
The statement added: “The new star systems contain only young blue stars, which are distributed in an irregular pattern and appear to exist in striking isolation from any potential parent galaxies.”
Michael Jones, a postdoctoral fellow at the University of Arizona Steward Observatory and lead author of a study describing the new star systems, said: “It’s a lesson in the unexpected.”
He added, “When you’re looking for things, you’re not necessarily going to find what you’re looking for, but you can find something very interesting.”
The statement says that the “blue spots” lie “within the relatively nearby Virgo cluster of galaxies. All five systems are separated from any potential parent galaxy by more than 300,000 light-years in some cases, making it difficult to identify their origins.”
The University of Arizona astronomers identified the new systems after another research group, led by Elizabeth Adams of the Netherlands Institute for Radio Astronomy, “compiled a catalog of nearby gas clouds, providing a list of potential sites of new galaxies.” .
Once the catalog was published, several groups of researchers, including a group led by University of Arizona associate professor of astronomy David Sand, began “looking for stars that might be associated with those gas clouds.”
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The statement said: “Gas clouds were thought to be associated with our own galaxy, and most of them probably are, but when the first collection of stars, called SECCO1, was discovered, astronomers realized it wasn’t. close to the Milky Way at all, but rather the Virgo cluster, which is much farther away but still very close on the scale of the universe.”
Jones said that SECCO1 was one of these unusual “blue spots.” He presented the findings, which Sand co-authored, at the 240th meeting of the American Astronomical Society in Pasadena, California, on June 15.
The statement also said: “The team obtained its observations from the Hubble Space Telescope, the Very Large Array Telescope in New Mexico, and the Very Large Telescope in Chile.
“Study co-author Michele Bellazzini, from the Istituto Nazionale di Astrofisica in Italy, led the analysis of the Very Large Telescope data and presented a companion paper focused on that data.
“Together, the team learned that most of the stars in each system are very blue and very young and contain very little atomic hydrogen gas. This is significant because star formation begins with atomic hydrogen gas, which eventually becomes in dense clouds of molecular hydrogen — hydrogen gas before they become stars.”
Jones said: “We see that most systems lack atomic gas, but that doesn’t mean there isn’t molecular gas.”
He added: “In fact, there must be some molecular gas because stars are still forming. The existence of mostly young stars and little gas indicates that these systems must have recently lost their gas.”
The statement said the combination of blue stars and a lack of gas was unexpected, as was the lack of older stars in the systems the experts discovered.
Jones said: “Stars that are born red are of lower mass and therefore live longer than blue stars, which burn up fast and die young, so old red stars are usually the last ones left alive.”
He added: “And they’re dead because they don’t have any more gas with which to form new stars. These blue stars are basically like an oasis in the desert.”
The new star systems are abundant in various metals, and Jones said: “For astronomers, metals are any element heavier than helium. This tells us that these star systems formed from gas that was sucked out of a large galaxy. , because how metals are built is by many repeated episodes of star formation, and you only really get that in a big galaxy.”
The statement said: “There are two main ways that gas can be extracted from a galaxy. The first is tidal extraction, which occurs when two large galaxies pass past each other and gravitationally rip the gas and stars apart. The other It is what is known as ram pressure. Peel.”
Jones said, “This is like diving into a swimming pool on your belly.” He added: “When a galaxy falls into a cluster that is filled with hot gas, its gas is ejected behind it. That’s the mechanism we think we’re seeing here to create these objects.”
The statement read: “The team prefers the ram pressure extraction explanation because for the blue spots to have become as isolated as they are, they must have been moving very fast, and the rate of tidal extraction is slow at comparison with the removal of the ram pressure”. Astronomers hope that one day these systems will eventually break up into individual star clusters and spread out into the larger galaxy cluster.”
Sand said what they have learned is a “bigger story of the recycling of gas and stars in the universe.”
He added: “We think this belly-dropping process changes many spiral galaxies into elliptical galaxies at some level, so learning more about the overall process teaches us more about galaxy formation.”
This story was provided to Newsweek by Zenger News.