Scientists have discovered a giant planet orbiting a brown dwarf star. It isn't just exciting that they found a new exoplanet, because it opens up a new world of information on what exactly a brown dwarf star actually is. Scientists are still not sure about the least bright start in the universe.
This new exoplanet is almost the size of Jupiter.
Researchers from KMTNet and the Optical Gravitational Lensing Experiment (OGLE) discovered the new exoplanet OGLE-2017-BLG-1522. The teams discovered the planet using a microlensing technique. It is currently orbiting a brown dwarf in the bulge of the Milky Way.
This is the first giant planet that has been observed orbiting a brown dwarf star. This suggests that the planet formed as first a disk around the star before forming into a planet. Brown dwarfs fall into a category that puts them above the heaviest gas giants and the lightest stars.
OGLE-2017-BLG-1522 was first observed on August 7, 2017, by the 1.3m Warsaw telescope at the Las Campanas Observatory in Chile. It is 25 percent smaller than Jupiter and orbits the brown dwarf at a distance of 0.59 AU.
The brown dwarf star that OGLE-2017-BLG-1522 orbits is 46 times larger than Jupiter. Researchers were able to discover the planet by using another brighter star that was behind the brown dwarf. The planet and brown dwarf would bend the light of the star that was behind them.
What Is A Planet?
Just like when Pluto lost its title of a planet in 2006, scientists are currently working on what may or may not be defined as a planet. Earlier in 2018, scientists began debating what could be defined as a planet or star.
Brown dwarf stars occupy a place between the heaviest gas planets and the lightest stars. At what point do people just call brown dwarfs heavy planets? Brown dwarfs are the dimmest stars that can be found in the universe and that can make their definition more difficult. Some gas giants emit the same amount of light as some brown dwarfs.
Scientists may have to come up with a different definition of a planet. All things can change with discoveries. More data could lead to a greater understanding of how planets or stars can form.
There have also been cases of exoplanets that are very far away from their host stars and have the same temperature as the host. Jupiter has been referred to as a failed star because it is made of the same elements as the Sun.