NASA's Chandra X-ray Observatory telescope may have discovered for the first time a planet outside the Milky Way Galaxy. If confirmed, the planet is thousands of times farther away than many exoplanets so far discovered.
Exoplanets tracked by astronomers are still in the area of the Milky Way or the Milky Way. That is, almost all of them are less than 3,000 light years from Planet Earth.
Exoplanets outside this galaxy, are in the neighboring galaxy to the Milky Way, known as M51 or also the Whirlpool Galaxy. The distance itself is about 28 million light years.
Researchers based on their research methods estimate that the planet is similar in size to the Planet Saturn. Then, it orbits a neutron star or black hole at twice the distance from Saturn to the Sun.
But these researchers admit they still need additional data to confirm this object is really a planet. One challenge is that the planet's massive orbit may make it undetectable for up to about 70 years.
"We know that we are making an interesting claim so we expect other astronomers to examine it carefully. We think we have a strong argument and this is how science works," said Julia Berndtsson, one of the researchers from Princeton University.
Basically, the method used to track it is the transit method. The path of a planet in front of its star will block some of the light from the star and make it dim. This event can be detected by telescopes from Earth.
Since they were first discovered more than a quarter of a century ago, the number of exoplanets, planets outside the Solar System orbiting stars, has grown rapidly. Reports in 2019 said the number had already touched the officially recorded 4,000 mark. Now, there may also be exoplanets outside the Milky Way Galaxy.
