Latest news with #KengoTachihara
Yahoo
12-04-2025
- Science
- Yahoo
The galaxy next to ours is being torn apart, study suggests
The galaxy next to ours might be getting torn apart, a study has suggested. The Small Magellanic Cloud, or SMC – a relatively small galaxy that neighbours ours – appears to be getting torn to bits by the gravitational pull of a neighbouring galaxy, the new research suggests. 'When we first got this result, we suspected that there might be an error in our method of analysis,' said Kengo Tachihara, from Nagoya University in Japan. 'However, upon closer examination, the results are indisputable, and we were surprised.' The SMC is one of our nearest neighbours, which allows researchers to keep close tabs on the roughly 7,000 massive stars that make up the galaxy. Those stars are more than eight times the mass of our Sun, and usually last for just a few million years before they explode into supernovae. As they watched those stars, researchers noticed that they appeared to be getting pulled apart by the Large Magellanic Cloud, or LMC, which itself neighbours the galaxy. 'The stars in the SMC were moving in opposite directions on either side of the galaxy, as though they are being pulled apart,' said Tachihara. 'Some of these stars are approaching the LMC, while others are moving away from it, suggesting the gravitational influence of the larger galaxy. 'This unexpected movement supports the hypothesis that the SMC is being disrupted by the LMC, leading to its gradual destruction.' Researchers also noticed that the SMC does not appear to be rotating. Usually, young massive stars move around along with the gas that they were born from – but the SMC's stars do not appear to be moving in that way, suggesting that the gas itself is not rotating as expected. That could lead to a new understanding not only of the SMC but also the way it interacts with galaxies including our own. Further the research could help us better understand the conditions and story of the early universe. The SMC is useful for understanding the cosmos when it was younger than it is today, because it shares some characteristics with early galaxies. 'We are unable to get a 'bird's-eye view' of the galaxy in which we live,' said Tachihara. 'As a result, the SMC and the LMC are the only galaxies in which we can observe the details of stellar motion. This research is important because it allows us to study the process of star formation in connection with the motion of stars throughout the galaxy.' The work is described in a new paper, 'Evidence of Galactic Interaction in the Small Magellanic Cloud Probed by Gaia-selected Massive Star Candidates', published in The Astrophysical Journal Supplement Series.
Yahoo
11-04-2025
- Science
- Yahoo
A gravitational war next door: The Large Magellanic Cloud is gradually destroying the Small Magellanic Cloud
When you buy through links on our articles, Future and its syndication partners may earn a commission. Two dwarf galaxies are waging war in the vicinity of our Milky Way and it looks like there is only one possible victor. Using tips from the star-tracking Gaia spacecraft, scientists examined the motions of massive stars in the Small Magellanic Cloud (SMC) to find it is being ripped apart by the gravitational influence of its larger counterpart, the Large Magellanic Cloud (LMC). The results spell disaster for the SMC, suggesting it may eventually be completely destroyed by this interaction. The SMC's loss is astronomers' gain, however, as this event can teach us more about galactic evolution. "When we first got this result, we suspected that there might be an error in our method of analysis. However, upon closer examination, the results are indisputable, and we were surprised," team co-leader Kengo Tachihara of Nagoya University said in a statement. "The stars in the SMC were moving in opposite directions on either side of the galaxy, as though they are being pulled apart. "Some of these stars are approaching the LMC, while others are moving away from it, suggesting the gravitational influence of the larger galaxy. This unexpected movement supports the hypothesis that the SMC is being disrupted by the LMC, leading to its gradual destruction." Thanks to the proximity of the SMC to our own galaxy, Tachihara and his colleagues were able to identify and track around 700 massive stars in the dwarf galaxy. These stars, with over eight times the mass of the sun, burn through their nuclear fuel supplies more rapidly than smaller stars do. This means they have much shorter lifespans. While the sun is expected to burn hydrogen in its "main sequence" lifetime for around 10 billion years, massive stars can exhaust their nuclear fuel in just a few million years. After exhausting their fuel supplies, the stars erupt in supernova explosions, leaving behind neutron stars or black holes. In addition to discovering stars moving in opposite directions on different sides of the SMC, the team also found that the stars in this dwarf galaxy lacked rotational motion. This is surprising because massive stars are born from clouds of collapsing interstellar gas, which, as we have seen in the Milky Way, do rotate. Plus, massive stars usually share that rotational motion when they are young, as they have not yet "decoupled" themselves from their pre-natal cocoons. This lack of rotating stars in the SMC hints that the interstellar gas in the dwarf galaxy may also not rotate. This could have implications for how we model the SMC and its interactions with the LMC and the Milky Way. "If the SMC is indeed not rotating, previous estimates of its mass and its interaction history with the Milky Way and LMC might need to be revised," team co-leader Satoya Nakano, also of Nagoya University, said in the statement. "This could potentially change our understanding of the history of the three-body interaction between the two Magellanic Clouds and the Milky Way." Related Stories: — Hubble Telescope spies star-forming cocoons in neighboring galaxy (photo) — Hidden monster black hole in the galaxy next door fired stars at us like million mph cosmic bullets — NASA wants a 'Super-Hubble' space telescope to search for life on alien worlds The new findings could help scientists better understand dynamic interactions between galaxies in general. Because the SMC and LMC share many characteristics with primordial galaxies in the early universe, such as the dearth of elements heavier than hydrogen and helium, this research could also help understand how the interactions of galaxies in the early universe shaped the cosmos as we see it today. "We are unable to get a 'bird's-eye view' of the galaxy in which we live," Tachihara said. "As a result, the SMC and the LMC are the only galaxies in which we can observe the details of stellar motion. "This research is important because it allows us to study the process of star formation in connection with the motion of stars throughout the galaxy." The team's research was published on Thursday (April 10) in The Astrophysical Journal Supplement Series.
The Independent
10-04-2025
- Science
- The Independent
The galaxy next to ours is being torn apart, study suggests
The galaxy next to ours might be getting torn apart, a study has suggested. The Small Magellanic Cloud, or SMC – a relatively small galaxy that neighbours ours – appears to be getting torn to bits by the gravitational pull of a neighbouring galaxy, the new research suggests. 'When we first got this result, we suspected that there might be an error in our method of analysis,' said Kengo Tachihara, from Nagoya University in Japan. 'However, upon closer examination, the results are indisputable, and we were surprised.' The SMC is one of our nearest neighbours, which allows researchers to keep close tabs on the roughly 7,000 massive stars that make up the galaxy. Those stars are more than eight times the mass of our Sun, and usually last for just a few million years before they explode into supernovae. As they watched those stars, researchers noticed that they appeared to be getting pulled apart by the Large Magellanic Cloud, or LMC, which itself neighbours the galaxy. 'The stars in the SMC were moving in opposite directions on either side of the galaxy, as though they are being pulled apart,' said Tachihara. 'Some of these stars are approaching the LMC, while others are moving away from it, suggesting the gravitational influence of the larger galaxy. 'This unexpected movement supports the hypothesis that the SMC is being disrupted by the LMC, leading to its gradual destruction.' Researchers also noticed that the SMC does not appear to be rotating. Usually, young massive stars move around along with the gas that they were born from – but the SMC's stars do not appear to be moving in that way, suggesting that the gas itself is not rotating as expected. That could lead to a new understanding not only of the SMC but also the way it interacts with galaxies including our own. Further the research could help us better understand the conditions and story of the early universe. The SMC is useful for understanding the cosmos when it was younger than it is today, because it shares some characteristics with early galaxies. 'We are unable to get a 'bird's-eye view' of the galaxy in which we live,' said Tachihara. 'As a result, the SMC and the LMC are the only galaxies in which we can observe the details of stellar motion. This research is important because it allows us to study the process of star formation in connection with the motion of stars throughout the galaxy.' The work is described in a new paper, 'Evidence of Galactic Interaction in the Small Magellanic Cloud Probed by Gaia-selected Massive Star Candidates', published in The Astrophysical Journal Supplement Series.
