Astronomers discover Earth-shaped ‘pie planet’ with 3.14-day orbit

In a delightful array of astronomy and mathematics, scientists at MIT and elsewhere have discovered a “pie earth” – an Earth-sized planet that zips around a star every 3.114 days, reminiscent of the stability of universal mathematics.

Researchers found signs of the planet in data taken in 2017 by NASA Kepler Space Telescope’s K2 mission. With a network of ground-based telescopes, Speculos, on the system earlier this year, the team confirmed that the signal was from a planet orbiting a star. And indeed, the planet still seems to be orbiting a star today, with a pie-like period, every 14.1 days.

“The planet rotates like a clock,” says Prajwal Niraula, a graduate student at MIT’s Department of Earth, Atmospheric and Eclipse Sciences (EAPS), who is the lead author of a paper published today. Astronomical Journal, Title: “π Meaning: A 3.14-day Earth-sized planet served by K2’s kitchen by the Speculos team.”

“Everyone needs a little fun these days,” says Julian de Witt, co-author of both Paper Title and The Discovery of the Pie Planet. “

Planet Extraction

The new planet is labeled K2-315b; It is the 5th5th planetary system that has been found within the 2 data – only one system of more sirendipitus place in the list is shy.

Researchers estimate that K2-315b has a radius of 0.95 compared to Earth, making it the size of Earth. It orbits a nice, low-mass star that is about one-fifth the size of the Sun. The planet orbits the star every 3.14 days, at a speed of 81 kilometers per second, or about 181,000 miles per hour.

While its mass is yet to be determined, scientists suspect that Earth-like 2-315b is terrestrial. But the pie planet is probably uninhabitable, as its tight orbit warms the planet close enough to its star to 450 Kelvin or about 350 degrees Fahrenheit-temperature, which turns out to bake a real pie.

“It would not be appropriate to dwell on the general understanding of this sentence,” says Niraula, adding that the excitement surrounding this particular planet, apart from the connection with the mathematical constant pie, could prove to be a promising candidate. To study the characteristics of its environment.

“We now know that we can mine the planets from archival data, and hopefully no planets will be left behind, especially on these really important issues that have more impact,” says De Witt, an assistant professor at EAPS. And a. Member of MIT’s Kavali Institute for Astrophysics and Space Research.

MIT co-authors with Niraula and De Witt include Benjamin Reckham and Artem Bardanov with a team of international collaborators.

Decrease in data

Researchers are members of Speculos, an acronym for Search for habitable planets Eclipse Ultra-Cool Stars, and named for a network of four 1-meter telescopes in the Atacama Desert of Chile, which scans the sky in the Southern Hemisphere. Recently, a fifth telescope was added to the network, located first in the Northern Hemisphere, called Artemis – a project that was spearheaded by MIT researchers.

Surrounding the Speculos Telescope, the ultracool dwarf-small, dim stars that give astronomers a better chance of finding an orbiting planet and characterizing its atmosphere are designed to explore the surrounding Earth-like planets, as these stars emit very large, bright stars. Is. .

“These ultracool dwarfs are scattered all over the sky,” says Bardanov. “Targeted ground-based surveys like Speculos are helpful because we can see this ultracool dwarf one by one.”

In particular, astronomers observe stars for transitioning or periodically sinking into the light of a star, signaling a possible planet crossing in front of the star, and briefly blocking its light.

Earlier this year, Niraula landed on an extreme dwarf, slightly warmer than the generally accepted threshold for an ultracool dwarf, or in data collected by K2 Expedition – another observation mission of the Kepler Space Telescope, which slides across the sky as it orbits the spacecraft. Was watching. Sun:

Over the course of several months in 2017, the Kepler Telescope observed a portion of the sky that included a cold dwarf, labeled EPIC 249631677 in K2 data. Niraula lengthened during this period and found about 20 dips in the light of this star, it seemed. Repeat every 3.14 days.

The team analyzed the signals, examining various possible astrophysical scenarios for their origin, and confirmed that the signals are the probability of a transiting planet, and not the product of some other phenomenon, such as the binary system of two other spiral stars.

The researchers then thought of taking a closer look at the star and its orbiting planet with speckles. But first, they had to recognize the time window when they would make sure to catch a transition.

“It’s a bit difficult to get the best night nails out of the ground,” Reckham said, developing a predictive algorithm to predict when a transition will occur. “Whenever you see this 3.14 day signal in K2 data, there is also an uncertainty, which increases with each orbit.”

With the rack ham prediction algorithm, the group collapsed on several nights in February 2020, during which they were seen crossing the planet in front of their star. They then turned their attention to the telescope of the speculus in the direction of the star and were able to see three clear transitions: two telescopes from the Southern Hemisphere of the network and a third from Artemis, in the Northern Hemisphere.

Researchers say the new pie planet could be a promising candidate to see details of Earth’s atmosphere with the James Webb Web Space Telescope (JWST). For now, the team is examining other datasets, such as from NASA’s Tess mission, and also directly observing the sky with Artemis and the rest of the Speculos network for signs of Earth-like planets.

“There will be even more interesting planets in the future, just in time for JWST, a telescope built to investigate the atmosphere of this alien world,” says Niraula. “With better algorithms, hopefully one day we will be able to find even smaller planets like Mars.” . ”