ARIZONA -- On Thursday, astronomers revealed a discovery of a new world in the Constellation Centaurus that experiences three sunsets and sunrises. Formally known as Planet HD 131399Ab, the newly discovered planet also has the biggest orbit ever known in a multi-star system. From the Earth's perspective, Planet HD 131399Ab takes 550 years to complete tracking its orbit around the sun.
"With three suns, the planet will see different weird combinations of sunrises and sunsets," said co-author Daniel Apai, a University of Arizona astronomer. "This is a system for which I would not want to design a calendar."
"If the planet was further away from the most massive star in the system, it would be kicked out of the system," Apai explained. "Our computer simulations have shown that this type of orbit can be stable, but if you change things around just a little bit, it can become unstable very quickly."
The astronomers used the European Southern Observatory's Very Large Telescope on Cerro Paranal in the Atacama Desert of northern Chile in finding the exoplanet — a planet outside of our solar system — which is 320 light years away from Earth and is believed to be four times the mass of Jupiter. Reported in the journal "Science," finding Planet HD 131399Ab marks the first discovery of an exoplanet using the SPHERE instrument (Spectro-Polarimetric High-Contrast Exoplanet Research Instrument), one of the most advanced instruments dedicated to finding planets around other stars.
Planet HD 131399Ab is reported to be about 16 million years old, making it one of the youngest exoplanets discovered and one of the very few exoplanets captured with direct images. It has a temperature of about 580 degrees Celsius, making it is also one of the coldest exoplanets discovered.
Long-term observations are still needed to determine the exact trajectory of the exoplanet among its host stars but so far it's believed the scenario is such that a star seeming to be 80% more massive than the Earth's sun is at the centre of the system and this star is also being orbited by two other less-massive stars which twirl around like a spinning dumbbell.