Researchers accidently discovered a planet forming around a star 553 light years away.
A U.S, Naval Research Laboratory (NRL) team looked at a protoplanetary disk (a large disk of material orbiting a newborn star from which a planetary system can form) around a star known as HD 100546. They were studying warm gas within the disk using a technique called spectro-astrometry, which allows them to detect even minute changes.
In their research the team noticed an "extra" source of gaseous emissions from carbon monoxide molecules that could not be coming from the disc alone. They calculated the changes in velocity and position of the extra emission over years of observations and found it was regularly orbiting the star. The evidence suggests they are observing the hot gas that normally surrounds a very young planet.
Through modeling the researchers were able to confirm their hypothesis and investigate the extra emissions. They believe the gas is coming from a "small circumplanetary disk of hot gas orbiting a forming planet," NRL reported. The forming planet would most likely be a gas giant about three times the mass of Jupiter.
Researchers believe material from large protoplanetary disks feed into circumplanetary disks, which in turn feed into a forming planet. The remnants of the circumplanetary disk could also contribute to the formation of moons.
The teams study is based on data gathered from four observations taken in 2003, 2006, 2010, and 2013 using the Gemini Observatory and the Very Large Telescope at the European Southern Observatory.
"These results provide a rare opportunity to study planet formation in action," said John Carr, a scientist at the U.S. Naval Research Laboratory (NRL). " Our analysis strongly suggests we are observing a disk of hot gas that surrounds a forming giant planet in orbit around the star. While such circumplanetary disks have been theorized to surround giant planets at birth and to control the flow of gas onto the growing planet, these findings are the first observational evidence for their existence. If our interpretation is correct, we are essentially seeing a planet caught in the act of formation."
In the future the researchers hope to continue monitoring the planet's motion and obtain more data on the properties of the circumplanetary disk. The baby planet and its disc will most likely become hidden by the circumstellar disk in two years and will not reappear for another 15 years.
The findings were published Aug. 20 in The Astrophysical Journal.
