According to a BBC report, astronomers have discovered signs of what was the first planet to be discovered outside our galaxy. Nearly 5,000 “exoplanets” of planets orbiting stars outside our Sun have been discovered so far, but they are all located within the Milky Way.
The potential planet is the size of Saturn and was discovered by NASA’s Chandra X – ray telescope and is located in the galaxy known as “Messier 51”.
The planet is about 28 million light-years from the Milky Way. This new discovery is based on the planets passing over each other, where a planet moving in front of a star blocks some of the star’s light and decreases the brightness detected by telescopes. This common technique has already been used to detect thousands of exoplanets.
Dr. Roseanne Di Stefano and his colleagues explored a decline in the brightness of X-rays from a type of object called bright binary X-rays. These objects usually have a neutron star or a sub-star near the black hole drawing gas, and the object near the neutron star or black hole becomes very hot and glows with X-ray wavelengths.
Because the area that produces the brightest X-rays is small, a planet in front of it can block most or all of the rays so that transport can be easily determined. Team members used this technique to locate candidate exoplanets in a binary system called “M51 – ULS – 1”.
In this regard, Dr. de Stefano, a researcher at the Harvard-Smithsonian Astronomical Center in Cambridge, USA, told the BBC: “The method we have developed and used is currently the only possible way to detect planetary systems in other galaxies.” Method, from which we can measure the light curve, ”he added. In this binary the black hole or neutron star orbits a sub-star that is 20 times heavier than the Sun. The neutron star is the collapsing center of what was once a massive star.