First Exoplanet in Another Galaxy Found

With more than 300 exoplanets discovered thus far inside the Milky Way, this field of astronomical research is expanding at an exponential rate. Despite the fact that a single extra-solar planet has thus far been identified directly, experts know that the other hundreds exist because they can detect their influence on their parent star. These formations either dim the brightness of the star when they pass in front of it, or they are so large in mass that they make it wobble. Both irregularities can be picked up by observatories on the planet or in Earth's orbit.

Just recently, Italian Scientist Gabriele Ingrosso, from the National Institute of Nuclear Physics, managed to discover the first such traces of an exoplanet, orbiting a far-away star, not in our galaxy, but in Andromeda. Once the discovery was confirmed, it made for the first-ever extra-solar planet to be seen in another galaxy. For the studies, Ingrosso and his team used an investigation technique known as microlensing, which allowed them to accurately detect the changes in a star's brightness and spin.

According to the research, the planet in Andromeda has a mass that is about six times larger than that of Jupiter, which means that it could also be a brown dwarf. However, the team seems convinced that it's a planet, simply because it's well within the mass range for a giant such as Jupiter. In the grand scheme of things, the largest planets in our solar system, such as Saturn and Jupiter, are dwarfed by some of the larger exoplanets out there, which have grown to be tens of times larger, over billions of years.

Up until now, the NINP team has used microlensing to capture fleeting glimpses of stars in Andromeda, and it was only by accident that the new extra-solar planet was found. Usually, the observation windows in which these bodies (stars and planets) can be seen are very limited, usually lasting hours to days. If astronomers are not looking in the correct area of the sky at the exact time, then they lose their opportunity for an undetermined period of time.