A team of photographers announced having for the first time photographed a planet being born. It was immortalised creating a path across the dust disc surrounding its star, an orange dwarf that is found 370 light years from the Earth.
A team of astronomers from the Max Planck Astronomy Institute, in Heidelberg in Germany, announced that they had captured the spectacular sight of a planet forming around dwarf star PDS 70. Christened PDS 70b, the planet can be very clearly distinguished, identified as a luminous dot to the right of the dark centre of the image at the head of the article. It is located around three billion kilometers from the central star, which is similar to the distance between Uranus and the Sun. The analysis also shows that PDS 70b is a giant gaseous planet that is larger than Jupiter. The researchers estimate its surface temperature at around 1200 degrees Kelvin, which makes it much hotter than any planet in our own solar system. It also takes 120 Earth years to orbit its sun.
We owe the dark spot at the center of the image to a coronograph (the SPHERE instrument, installed on ESO’s Very Large Telescope), a mask which blocks out the blinding light of the central star, which allows astronauts to detect the far weaker disc and its planetary companion. Without this mask, the weak luminosity of the planet would be completely overthrown by the intense luminosity of PDS 70.
We know that when stars are newly formed, they are orbited by a disc composed of dust, rocks and gas, swirling around their equators. We believe that planetary accretion happens when these particles collide with each other, becoming gradually gravitationally stronger. The material comes increasingly together, until a planet is formed. Astronomers have managed to capture several protoplanetary discs, but photographing a planet in the course of being born is quite another thing. In fact, exoplanets are often too far away, and thus too feeble to be caught by our optic telescopes.
Although we are not talking about a potentially habitable world here, this planet in formation is the first to be confirmed as such, which reflects an important discovery for science. It allows for another viewpoint on the first complex and poorly understood phases of the evolution of planets.