ESO’s Very Large Telescope Directly Images Newborn Exoplanet

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Astronomers using the SPHERE instrument on ESO’s Very Large Telescope have found an infant gas giant orbiting the young dwarf star PDS 70. Not only have they detected the planet, but they’ve also taken a direct image of it.

This image from the SPHERE instrument on ESO’s Very Large Telescope is the first clear image of an exoplanet caught in the very act of formation. The planet stands clearly out, visible as a bright point to the right of the center of the image, which is blacked out by the coronagraph mask used to block the blinding light of the central star. Image credit: ESO / A. Müller et al.

This image from the SPHERE instrument on ESO’s Very Large Telescope is the first clear image of an exoplanet caught in the very act of formation. The planet stands clearly out, visible as a bright point to the right of the center of the image, which is blacked out by the coronagraph mask used to block the blinding light of the central star. Image credit: ESO / A. Müller et al.

PDS 70, also known as V* V1032 Cen, is a K7-type pre-main sequence star located 370 light-years away from Earth.

The star is only 5.4 million years old and is surrounded by a protoplanetary disk with an embedded, still-forming planet, PDS 70b.

“Protoplanetary disks 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 Max Planck Institute for Astronomy researcher Dr. Miriam Keppler, who led the team behind the discovery of PDS 70b.

“The problem is that until now, most of these planet candidates could just have been features in the disk.”

The analysis shows that PDS 70b is a gas giant with a mass between 1.4 and 3.7 Jupiter masses.

The planet is located about 22 AU (astronomical units) from the host star, roughly equivalent to the distance between Uranus and the Sun.

PDS 70b’s surface has a temperature of around 1,800 degrees Fahrenheit (1,000 degrees Celsius), making it much hotter than any planet in our own Solar System.

In a separate study, Dr. André Müller of the Max Planck Institute for Astronomy and co-authors followed up the initial observations to investigate PDS 70b in more detail.

The researchers not only captured the direct image of the planet, but were even able to obtain its spectrum.

The analysis of the spectrum indicated that the planet’s atmosphere is cloudy.

“PDS 70’s planetary companion has sculpted a transition disk — a protoplanetary disk with a giant ‘hole’ in the center,” the astronomers said.

“These inner gaps have been known about for decades and it has been speculated that they were produced by disk-planet interaction. Now we can see the planet for the first time.”

“These results give us a new window onto the complex and poorly-understood early stages of planetary evolution,” Dr. Müller said.

“We needed to observe a planet in a young star’s disk to really understand the processes behind planet formation.”

The results will be reported in two papers to appear in the journal Astronomy Astrophysics.

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M. Keppler et al. 2018. Discovery of a planetary-mass companion within the gap of the transition disk around PDS 70. AA, in press; arXiv: 1806.11568

A. Müller et al. 2018. Orbital and atmospheric characterization of the planet within the gap of the PDS 70 transition disk. AA, in press; arXiv: 1806.11567