Astronomers capture the first ever image of a 'new-born planet'
It is official. For the very first time ever, astronomers have managed to capture the image of a planet 'being born' in our galaxy as it moves through a vast ocean of planet-forming dust and gas around its sun, an orange dwarf almost 370 light-years away from Earth.
The European Southern Observatory ESO, a 15-nation intergovernmental astronomy research organisation announced on Monday that astronomers led by a group at the Max Planck Institute for Astronomy in Heidelberg, Germany, captured a spectacular snapshot of planetary formation around a young dwarf star PDS 70.
Photographing the formation of a planet is not an easy task given that most exoplanets are too faint to be picked up by optical telescopes here on Earth. Any light reflected by an exoplanet is usually obscured by the brightness of its star - this being the reason that stars are not visible on earth to the naked eye during daytime.
By using the SPHERE instrument on ESO's Very Large Telescope (VLT) based in Chile - one of the most powerful planet-hunting instruments in existence – the ESO team detected a young planet, named PDS 70b, moving through the planet-forming material surrounding the young star.
The SPHERE instrument also enabled the team to measure the brightness of the planet at different wavelengths, which allowed properties of its atmosphere to be deduced. The ESO described the discovery of the star's young planetary companion as an exciting scientific result that merits further investigation.
A second team, involving many in the original discovery team, has in the past months followed up the initial observations to investigate PDS 70b in more detail. They not only made the spectacularly clear image of the planet but were even able to obtain a spectrum of the planet. Analysis of this spectrum indicated that its atmosphere is cloudy.
According to the astronomers, PDS70b is a giant gas planet with a mass that is a few times that of Jupiter and has a surface temperature of around 1000°C – that is much hotter than any planet in our own solar system. The dark region at the centre of the image is due to a coronagraph, a mask which blocks the blinding light of the central star and allows astronomers to detect its much fainter disc (rotating circumstellar disk of dense gas and dust surrounding a young newly formed star) and its planetary companion. Without this mask, the faint light from the planet would be utterly overwhelmed by the intense brightness of PDS 70.
"These discs around young stars are the birthplaces of planets, but so far only a handful of observations have detected hints of baby planets in them," explained Miriam Keppler, who led the team behind the discovery of PDS70's still-forming planet and is also the lead author of two research articles on the new discovery. "The problem is that until now, most of these planet candidates could just have been features in the disc."
Two studies on PDS70 star and its planetary companion were published in the journal Astronomy & Astrophysics last week.
Scientists believe that when stars are newly formed, they are orbited by a swirling disc of dust, rocks and gas. Planet formation is thought to occur when these particles collide with each other and gradually grow stronger gravitationally. The material thus collected from the orbital path eventually forms a planet.
You can watch a YouTube video by ESO on the discovery by clicking here