The Magellanic Clouds are nearby dwarf galaxies that we can easily see from Earth’s southern hemisphere. There are two—or so it was believed until now—: the Large Magellanic Cloud and the Small Magellanic Cloud. But the latter held a surprise: a new investigation Maintains that What appeared to be a single galaxy is actually two.
The confusion has to do with the fact that one is behind the other, from the perspective we have from our planet. The Small Magellanic Cloud – also known as SMC – is one of the most studied star systems in our universe due to its proximity. It is about 200,000 light years from Earth
The curiosity of astronomers is greater because its structure and elements are very different from those of our galaxy, the Milky Way. For example, it is of lower metallicity and is therefore an excellent laboratory for understanding the physics of the interstellar medium (ISM). The latter is the gas and dust between stars within a galaxy, while the circumgalactic medium is the gas and dust between galaxies.
A large international team of astronomers and astrophysicists verified that the chemical composition of two “parts” of the Small Magellanic Cloud are different. They also discovered that they had different speeds: one area closer to Earth was moving faster than the other. Furthermore, they observed that both had a similar mass.
A global team to study the galaxies of the Small Magellanic Cloud
Therefore, the researchers concluded that, ultimately, the evidence strongly points to two different dwarf galaxies. The closest is approximately 199,000 light years away, while the most distant is about 215,000 light years from us.
In the late 1980s, the first clues appeared suggesting that these were two galaxies. Now, the evidence was confirmed thanks to the contribution of precise data from several observatories around the world.
The research team first studied data from the European Space Agency’s Gaia space observatory, which allowed them to make estimates of the average speed of stars in various parts of the Small Magellanic Cloud. Next, they studied data from the Australian Square Kilometer Array Pathfinder (ASKAP), a radio telescope array located at the Murchison Radio Astronomy Observatory (MRO), in Australia. In this way, they analyzed the interstellar medium.
Another team that collaborated was from the Apache Point Observatory in New Mexico. This center coordinates research at the Sloan Foundation Telescope and the NMSU Telescope.
The Small Magellanic Cloud is full of mysteries. NASA’s James Webb Telescope recently discovered star formation in the dusty ribbons of this cluster. His team was exploring the known region as NCG 346 and discovered more than 33,000 young stars embedded in the nebula.
The conditions of the Small Magellanic Cloud resemble those observed in galaxies that existed billions of years ago. It is an era of the universe known as the “cosmic noon”when star formation was at its peak.