Extragalactic planet Extragalactic planet An extragalactic planet, also known as an extragalactic exoplanet, is a star-bound planet, or rogue planet, located outside of the Milky Way galaxy. Due to the huge distances to such worlds, they would be very hard to detect directly. However, indirect evidence suggests that such planets may exist. Nonetheless, the most distant known planets are SWEEPS-11 and SWEEPS-04, located in Sagittarius, approximately 27,710 light-years from the Sun, while the Milky Way is between 100,000–180,000 light years in diameter. This means that even galactic planets located further than that distance have not been detected. A planet with a mass
Extragalactic background light the galaxy populations that is directly observed over the range of redshifts that contribute significantly to the EBL. Extragalactic background light The diffuse extragalactic background light (EBL) is all the accumulated radiation in the universe due to star formation processes, plus a contribution from active galactic nuclei (AGNs). This radiation covers almost all wavelengths of the electromagnetic spectrum except the microwave covered by primordial Cosmic Microwave Background. The EBL is part of the diffuse extragalactic background radiation (DEBRA), which by definition covers the overall electromagnetic spectrum. After the cosmic microwave background, the EBL produces the second-most energetic diffuse background, thus