Planetary engulfment illustration

The NASA/ESA/CSA James Webb Space Telescope’s observations of what is thought to be the first ever recorded planetary engulfment event revealed a hot accretion disk surrounding the star, with an expanding cloud of cooler dust enveloping the scene. Webb also revealed that the star did not swell to swallow the planet, but the planet’s orbit actually slowly decayed over time. The star is located in the Milky Way galaxy about 12,000 light-years away from Earth. 

This illustration depicts the sequence of events that took place over millions of years, based on observations from Webb’s MIRI (Mid-Infrared Instrument) and NIRSpec (NIR-Infrared Spectrograph).

Panel 1: The planet was about Jupiter-sized, and orbited very close to the star – even closer that Mercury’s orbit around our Sun.

Panel 2: The planet’s orbit slowly shrank, or decayed, over time, and the planet approached the star. It eventually started to graze the star’s atmosphere. As the planet was falling in, it smeared around the star.

Panel 3: The planet was engulfed by the star completely, and blasted gas away from the outer layers of the star.

Panel 4: As that gas expanded and cooled off, the heavy elements in this gas condensed into cold dust over the next year. There is a hot circumstellar disk of molecular gas closer to the star.

These findings appear today in The Astrophysical Journal.

[Image description: A four panel illustration. Panel 1 shows a host star, which looks like an orange globe with flares coming out on various sides. There is a blue line with arrows forming a spiral around the star. At 2 o’clock in the outer spiral, furthest away from the star, there is a blue planet. Panel 2 shows the same star and lines, but the planet is now at 7 o’clock and closer to the star. It is a little stretched out toward the star. Panel 3 shows the same star and lines, but the planet is fully engulfed by the star, with big flares coming out where the planet and star collided. Panel 4 shows the aftermath, with a very transparent cloud of blue dust spread out from the star. A dark orange horizontal ring of material circles the host star.]