What It Looks Like When a Dying Star Eats a Planet

The end of the world as we know it is imminent

The finding of a fading star engulfing a sizable planet by astronomers completes a "missing link" in our knowledge of Earth's and many other planets' histories.

Astronomers have seen a star devour a planet, providing the first up-close look at the nasty phenomenon known as planetary engulfment that almost certainly awaits Earth in the far future.

A gas planet similar to Jupiter, but perhaps larger, was accidentally discovered by scientists while it was being engulfed by an old sun-like star some 12,000 light-years from Earth. Previous observations have provided tantalizing signs of engulfment occurrences, but no one has ever observed a star actually engulfing a planet.

According to the astronomers' study, which was released on Wednesday in the journal Nature, the discovery "provides a missing link in our understanding of the evolution and final fates of planetary systems," including the one we currently call home.

Kishalay De, a NASA Einstein fellow at the Massachusetts Institute of Technology and one of the study's authors, stated, "This is the Earth's ultimate fate." "We are actually witnessing what the Earth will face in five billion years."

The mass of a star affects its life cycle. The most massive stars explode within a few million years after their birth, but small stars, like red dwarfs, may shine for billions of years. After billions of years, stars like the sun begin to die. When this happens, they change into a class of objects called red giants, which grow hundreds of times larger and devour everything in their path.

Across the Milky Way, there are numerous indications of engulfment events. Some stars' light is tainted by the chemical traces of planets, implying that entire worlds are being consumed right before our eyes. A large number of planets with tight orbits that will eventually be sucked into the radii of red giants have also been discovered by scientists.

However, despite the fact that occasionally planets are clearly devoured by stars, it is difficult to capture this moment because the light produced by these occurrences is weak and fleeting. In reality, in May 2020, Dr. De was searching for something very different — merging stars known as red novas — using the Zwicky Transient Facility, a camera mounted on a telescope at the Palomar Observatory in California. He discovered an intriguing flash of visible light during his investigations.

What happened resembled a "detective story," according to Dr. De. His team used measurements of the source made in visible light by the Hawaii-based W.M. Keck Observatory in November 2020 to pinpoint the burst. These photographs showed a star that was roughly 5,000 degrees Fahrenheit, which is about 10 times cooler than the red novas' scorching temperatures.

Dr. De and his associates were perplexed and decided to investigate the star once more, this time in infrared light, with the aid of a different camera at the Palomar Observatory and NASA's NEOWISE satellite observatory. The device proved to be extremely effective in the infrared region of the light spectrum, which is perfect for identifying small, low-energy objects. The scientists then realized that they were probably witnessing a star devour a planet in real time.

My initial response was incredulity, said Dr. De. He said that although "we see the before and after" of planetary engulfment, "these observations give us the first glimpse into how that process plays out."

A dying star finally totally engulfed a gas planet little more than ten times the mass of Jupiter when the initial explosion, which lasted ten days, was first noticed by the Zwicky observatory. The planet skirted the star's periphery for more than a year before to its brilliant end, ripping off pieces of its atmosphere, which accounts for the cold gas and dust the researchers saw hovering around the system. Following the explosion, the star gave off an eerie glow for about six months as it ate up the planet's remains.

The team's findings were hailed as "groundbreaking" and "very solid" by Lorenzo Spina, an astrophysicist who researches planetary engulfment at the Astronomical Observatory of Padua in Italy.

Dr. Spina remarked that "this is a very important missing piece of the entire story." "Now that we have a better understanding of the entire process, we can move forward."

Such extraordinary occurrences can offer insight on a variety of intriguing questions, such as the possibility that life may exist elsewhere in the cosmos. For insights regarding the internal makeup of worlds in neighboring systems, one can mine starlight that carries chemical traces of planetary scraps. The number of star systems with the necessary components to enable habitable environments may be estimated with the use of a list of these components.

Now that researchers have actually witnessed planetary engulfment, they may look for patterns in the sky that resemble those in the model. The latest discoveries also offer a gruesome prelude to the actual end of the planet. It seems conceivable that our familiar home planet will perish in the sun's hellish embrace when it enters its red-giant phase.

The discovery of an event like this, according to Dr. De, "really puts all of the theories that have been out there to the most rigorous tests possible." It truly opens up this brand-new area of study.