Birth of a planet captured for first time as gas giant bigger than Jupiter swirls into existence
Even by astronomical standards it is a discovery that is out of this world.
Scientists have for the first time witnessed the birth of a planet, a huge gas giant many times the size of Jupiter, swirling into existence 370 light years from Earth.
The theory of how gas planets form from a vortex of hydrogen and helium molecules captivated by their own gravity, is now widely accepted by scientists. But it has never been seen before, until now.
Today scientists at the Max Planck Institute for Astronomy (MPIA) in Heidelberg and the SPHERE instrument consortium at the Very Large Telescope of the European Southern Observatory (ESO) in Chile, released a spectacular image of the birth
The planet, currently known as PDS 70b, is shown orbiting within a huge spinning ‘protoplanetary disc’ of gas and dust, which proves it is continuing to accumulate matter, and so is not yet fully formed.
The newborn sits within a 5.4 million year old solar system, orbiting a star called PDS 70 at a distance of 1.8 billion miles.
The planet stands out clearly in the image, visible as a bright point to the right of the blackened centre.
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 the faint light from the planet.
“For our study, we selected PDS 70, a star that was already suspected of having a young planet circling around it,” says Miriam Keppler, doctoral student at MPIA.
“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.
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“The problem is that until now, most of these planet candidates could just have been features in the disc."
This glimpse of the dust-shrouded birth of a planet was only possible because of ESO's SPHERE instrument, which studies exoplanets and discs around nearby stars using a technique known as high-contrast imaging.
Using the instrument, astronomers were able measure the brightness of the planet at different wavelengths, and find out its composition.
It is located roughly three billion kilometres from the central star, roughly equivalent to the distance between Uranus and the Sun. The planet takes about 120 years to orbit its host star.
Spectral analysis shows PDS 70 b is a giant gas planet, with a mass a few times that of Jupiter and a surface temperature of around 1,000C, making it much hotter than any planet in our own solar system.
Signs of life in our Solar System
Thomas Henning, director at the Max Planck Institute for Astronomy and leader of the teams, summarises the scientific adventure: "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.”
To date, astronomers have discovered around 3,800 exoplanets outside of the solar system but have never seen one being born.
“The results give us a new window onto the complex and poorly-understood early stages of planetary evolution," said Dr André Müller, leader of the second team to investigate the young planet.
“We needed to observe a planet in a young star's disc to really understand the processes behind planet formation."
