The Milky Way is believed to be stealing stars from a neighbouring galaxy being steadily consumed by a supermassive black hole, scientists suspect.
Researchers have proposed that the galaxy is stealing from its dwarf neighbour, Leo I, thought to be a Milky Way satellite.
Leo I is 830,000 light years away and orbits the Earth’s home galaxy in an elliptical trajectory, and is occupied by a supermassive black hole, according to the recent study.
Publishing in the Astrophysical Journal Letters, scientists suggested Leo I, despite being approximately 10,000 smaller, has a black hole roughly equivalent to the Milky Way’s.
The study authors explained the discrepancy is much larger than what they would expect of most galaxies, and theorised this was because it has been stripped away by our home galaxy for aeons.
Scientists said Leo I was likely much larger in the distant past but was overcome by the Milky Way’s stronger gravitational pull, which snatched some of its stars during close encounters.
The Harvard-backed study led by Fabio Pacucci, a researcher with the Harvard–Smithsonian Center for Astrophysics, used a simple model that found it may have lost between 32 and 57 per cent of stars in one close brush.
Upper estimations placed the potential loss between 66 and 78 per cent, but the authors said this was an extreme scenario.
Detailed simulations run by the team estimated the Leo I’s likely size before it was picked apart by the Milky Way.
They found the galaxy may have boasted a total mass of one billion solar masses and concluded it could have been reduced to its current state in roughly eight billion years.
The Milky Way likely prized the stars from its neighbour’s grasp in just two passes.
If their hypothesis is proven accurate, it could mean that further brushes with the galaxy could mean the supermassive black hole could start “wandering” through deep space.
The scientists predicted Leo I’s black hole is likely halfway through the process at present, which would eventually see it untethered to any other galaxy.
They stressed they are yet to confirm for certain whether their theories are accurate and added their research would require further study.
Even if they can only confirm the presence of the black hole, the astronomical object would be “an exceptional laboratory for studying the intimate connection between black holes and their host galaxies”, the researchers concluded.