As humanity’s diligent efforts to explore and discover the expanse of the universe continue, we have come a little closer to understanding the beginnings of our own solar system. Allowing this pursuit is a new study which reports the discovery of a “baby” planet orbiting a nearby red dwarf star.
Called ‘AU Mic b’, and in orbit, AU Microscopii or ‘AU Mic’, the planet is roughly the size of Neptune. AU Mic is a red dwarf, which is the smallest and freshest variety of stars in the vast range of stars in the universe and which is of very low mass.
It is the second closest young star to Earth. “This is an exciting discovery, especially since the planet is in one of the best-known young star systems and the second closest to Earth,” said Michael Bottom, co-author of the study.
Discover a “baby” planet
Astronomers from the University of Hawai’i in Manoa, who are part of an international tea, have discovered the planet. AU Mic b requires only eight and a half days for the completion of an orbit. NASA’s planet search satellite TESS spotted the planet as it periodically passed AU Mic.
Each time it passed the star, it blocked a small fraction of its light. Confirmation of the signal was provided by observations from the Spitzer Space Telescope and the NASA Infrared Telescope Facility (IRTF) located on Maunakea Island in Hawaii. For the observations made on the island, a new instrument known as the iSHELL, which accurately measures the movement of stars like the AU Mic.
As the star “flickered” in response to the planet’s gravitational pull, the oscillation was measured by the instrument. ISHELL measurements have conclusively proven that AU Mic b was a planet. If he had been a companion star, the oscillation or movement would have been considerably greater.
Still in its infancy
As for the age of the star and the planet, astronomically, they are still in their infancy. Scientists say the system is only about 25 million years old. In fact, the youth of this planet is characterized by the debris and dust left after its formation and in orbit around it.
When the debris collides, they disintegrate into smaller dust particles that orbit the star like a thin disk. The disc was detected using the 88-inch UH telescope on Maunakea in 2003. The new AU Mic b orbits the region which is erased inside the disc.
Expressing hope for the possibility of finding other planets in the system, Bottom said: “In addition to the debris disc, there is always the possibility of additional planets around this star. AU Mic could be the gift that keep giving. “
Eric Gaidos, another co-author of study, pointed out that as the planets mature, they change. This includes movement in their orbits and changing the composition of their atmospheres. He explained, “Some planets are getting warmer and cooler, and unlike people, they will get smaller over time. But we need observations to test these ideas, and planets like AU Mic b are a great opportunity.”
Provide clues to the beginnings of Earth-like planets
In addition to its age younger than the Sun, AU Mic is also much darker, redder and smaller, as it is a red dwarf. Several Earth-sized planets continue to be discovered by the TESS satellite around older red dwarfs. Some of them could be habitable. The inclinations of AU Mic b and its star can allow a better understanding of the history of these detected planets.
Speaking of how discoveries of the star and the planet can facilitate future discoveries, Gaidos added, “AU Mic b, and all the related planets that will be discovered in the future, will be intensely studied to understand how the planets form and evolve. Fortunately, this star and its planet are at our cosmic door. We do not have to go very far to see the show. “