Astronomers using ESO’s Very Large Telescope (VLT) have captured an incredible image of a Jupiter-size planet forming around dwarf star PDS 70. This detection is the telescope’s first planetary formation discovery.
The achievement is reported in two papers published in Astronomy & Astrophysics (here and here). The planet, PDS 70b, weighs a few times the mass of Jupiter and orbits its star at a distance of 3 billion kilometers (1.8 billion miles), slightly further than Uranus is from the Sun. It is also quite hot with a temperature of at least 1,000 degrees Celsius (roughly 1,800 degrees Fahrenheit), definitely hotter than any planet in the Solar System.
The discovery was possible thanks to the new VLT instrument SPHERE (Spectro-Polarimetric High-contrast Exoplanet REsearch instrument), one of the best planet-hunting instruments ever built. The team was able to block the light from the bright star and focus on the disk of material surrounding it. The gap in the material has been known to astronomers for a long time, and now they have finally spotted the planet they suspected existed there.
“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,” lead author Miriam Keppler, from the Max Planck Institute for Astronomy, said in a statement. “The problem is that until now, most of these planet candidates could just have been features in the disc.”
The planet is presumed to be in a very early phase of planetary formation. It is estimated to be 5.4 million years old. And that’s not all. After several years of observations, the researchers have learned a lot about the object. The planet’s orbit is roughly circular around the star and it orbits in the same plane as the disk.
“Keppler’s results give us a new window onto the complex and poorly-understood early stages of planetary evolution,” added 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.”
The observation allowed the researchers to determine the general properties of the planet and its atmosphere. Catching a planet so early in its life, and learning so much about it, gives us very important insights to test against our theoretical models of planet formation.