A huge but deeply damaged galaxy has identified a team of researchers from Israel, the US and Russia.
The galaxy, which resembles a tentacle, is more than 300 million light-years away from Earth. This is described by leading investigator Noah Brosch of the Florence Observatory and George Wise at Tel Aviv University as "disturbed" because it is clearly exposed to massive external forces.
Generally, broken galaxies are relatively small – the result of their stars being either integrated into a more massive galaxy, or bulk in space as a result of a titanic collision between two star systems.
The latest findings, however, are likely to trigger a review of the obstacles to the survival of such systems.
"We have discovered a huge, remarkable memorial of a broken galaxy," says Brosch.
The structure that is inside a cluster of smaller galaxies called Hickson's compact group 98 is huge. Approximately one million light-years from the end to the end, it is ten times the size of the Milky Way.
"What is the extraordinary subject is that the tail itself is nearly 500,000 light years," says co-author Michael Rich of the University of California at Los Angeles.
"If it were at a distance of about 2.5 million light-years from the Earth, the Andromeda galaxy would have reached a fifth of the way to our own Milky Way."
Brosch and his colleagues suggest that galactic matter originated as a result of the previously invisible star-filled dwarf galaxy, which was divided by the gravitational forces of two larger galaxies, and its components were dramatically redistributed.
"The extragalactic frog contains a system of two very close" normal "disk galaxies, each with a diameter of 40,000 light-years," says Brosch. "Together with other nearby galaxies, the galaxy is a compact group."
This group, scientists remain, is far from the steady system. It is expected that all members of Hickson's compact group 98 will join a giant galaxy in about a billion years – when it is likely that the extragalactic pack will turn into a cosmic frog.
Research is published in Monthly announcement of the Royal Astronomical Society.