Astronomers recently detected signs of a planet transiting a star outside of the Milky Way. Although it is still too early to confirm it, this could be the first planet discovered outside our galaxy ever.
So far, nearly 5,000 planets orbiting beyond our solar system have been discovered. However, as scientists lacked the technology to reach such distances, these exoplanets have always been inside the Milky Way.
Now, using NASA’s Chandra X-Ray, the planet was spotted in the Messier 51 galaxy, 28 million light-years away from our home.
Thanks to the new observatory, researchers detected dimming X-rays in a planetary system. Current hypotheses state that this dimming was caused by a planet eclipsing a neutron star emitting X-ray light.
In order to reach such conclusions, they studied X-ray transits in different galaxies. This basically meant searching for dips in the light that could be explained by planets. Once they discovered one in M51, they continued their investigation.
Based on their discoveries, professionals learnt more about the dimensions and orbit of the possible plant. They estimate it is close to the size of Saturn and orbits a neutron star or black hole.
These fascinating results have opened up a lot of research opportunities for astronomers. Not only do they have new investigative technology, but they can reach extraordinary distances.
“We are trying to open up a whole new arena for finding other worlds by searching for planet candidates at X-ray wavelengths, a strategy that makes it possible to discover them in other galaxies,” said Rosanne Di Stefano of the Center for Astrophysics Harvard & Smithsonian who led the study.
Nonetheless, there are various limitations to such studies. In this recent case, the current data is not sufficient to determine the identity of the possible planet, but astronomers face an enormous challenge. Due to its large orbit, the potential exoplanet will not eclipse the light again for 70 years.
“Unfortunately to confirm that we’re seeing a planet we would likely have to wait decades to see another transit,” said Nia Imara of the University of California at Santa Cruz. “And because of the uncertainties about how long it takes to orbit, we wouldn’t know exactly when to look.”
Bibliography
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Carter, J. (2021, October 25). The First Planet Outside Of Our Milky Way Galaxy Has Been Discovered During An ‘X-Ray Eclipse’ Say Excited Scientists. Forbes. https://www.forbes.com/sites/jamiecartereurope/2021/10/25/the-first-planet-outside-of-our-milky-way-galaxy-has-been-discovered-during-an-x-ray-eclipse-say-scientists/?sh=2043538b67c4
Geddes, L. (2021, October 26). Astronomers spot first possible exoplanet outside our galaxy. [Photograph]. The Guardian. https://www.theguardian.com/science/2021/oct/26/astronomers-spot-first-possible-exoplanet-outside-our-galaxy
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