Two papers released this week by the European Southern Observatory (ESO), and soon to be published in the journal Astronomy & Astrophysics, revealed that astronomers led by the Max Planck Institute for Astronomy in Heidelberg, Germany have captured the first confirmed image of a planet's birth. The impressive snapshot shows the formation of a young planet named PDS 70b emerging from the dwarf star PDS 70.
A light-blocking mask
The picture was made possible by the presence of a coronagraph, a mask blocking the blinding central star's light. The coronagraph can be seen in the dark region at the center of the snapshot and it is its light-blocking properties that made the star's disc and baby planet visible.
The picture clearly reveals PDS 70’s sculpted transition disc, an inner gap stipulated by scientists for decades as being the byproduct of disc-planet interactions. The image marks the first time the newly birthed planet can be seen.
“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,” said Miriam Keppler, team leader, in a statement. “The problem is that until now, most of these planet candidates could just have been features in the disc.”
A hot giant gas planet
The picture was collected using the SPHERE instrument on ESO’s Very Large Telescope which also enabled the team to record the planet's brightness in order to deduce its atmosphere's properties. The team discovered that PDS 70b is a giant gas planet bigger than Jupiter and with a surface temperature of around 1000°C, far surpassing any hot planet in Earth's Solar System.
A second team was put together to further investigate the baby planet. The new scientists, many of whom were involved in the initial discovery, were successful in obtaining a spectrum of the planet that revealed a cloudy atmosphere.
“Keppler’s results give us a new window onto the complex and poorly-understood early stages of planetary evolution,” said André Müller, leader of the second team. The data acquired on the new planet’s atmospheric and physical properties will now allow the astronomers to test theoretical models of planet formation.
The discoveries were due to ESO’s SPHERE instrument that uses a unique technique known as high-contrast imaging which enables it to employ observing strategies and data processing systems to capture the faintest of signals. “After more than a decade of enormous efforts to build this high-tech machine, now SPHERE enables us to reap the harvest with the discovery of baby planets!” said Thomas Henning, director at the Max Planck Institute for Astronomy and leader of the teams.
SPHERE's images are the result of two survey programmes called SHINE (SpHere INfrared survey for Exoplanets) and DISK (sphere survey for circumstellar DISK). SHINE aims to image 600 young nearby stars while DISK targets known, young planetary systems and their circumstellar discs.