Gliese 367 b – An Oddball Ultrashort Period Planet

Gliese 367 b – An Oddball Ultrashort Period Planet

Gliese 367 b – An Oddball Ultrashort Period Planet

Gliese 367 b, also known as Tahay, is an extraordinary exoplanet that orbits its star in just 7.7 hours. What sets this planet apart is not only its ultrashort period, but also its incredibly high density, almost twice that of Earth. Researchers have described Gliese 367 b as an “ultra-dense” planet, predominantly composed of iron.

Discovered in 2021 using data from the Transiting Exoplanet Survey Satellite (TESS), Gliese 367 b has recently been the subject of further study to refine its mass and radius measurements. This research, published in The Astrophysical Journal Letters, not only provides more accurate measurements of Gliese 367 b but also reveals the existence of two additional low-mass planets in the same system.

The study, titled “Company for the Ultra-high Density, Ultra-short Period Sub-Earth GJ 367 b: Discovery of Two Additional Low-mass Planets at 11.5 and 34 Days,” was led by Elisa Goffo, a Ph.D. student at the University of Turin. Goffo and her team used the High-Accuracy Radial Velocity Planet Searcher (HARPS) spectrograph to obtain more precise measurements of Gliese 367 b.

The new results show that Gliese 367 b is even denser than previously thought. Its mass is now estimated to be 63 percent that of Earth, and its radius has shrunk to 70 percent. This makes Gliese 367 b twice as dense as our planet. The researchers believe that Gliese 367 b is likely the stripped core of a larger planet, similar to Earth without its rocky mantle.

Various formation scenarios have been proposed to explain how Gliese 367 b ended up in its current state. One possibility is that it experienced a catastrophic event early in its development, causing its rocky mantle to be stripped away. Another theory suggests that Gliese 367 b was born in an iron-rich region of a protoplanetary disc. Alternatively, it may have been a gas giant like Neptune that migrated closer to its star, with intense irradiation boiling away its atmosphere.

The discovery of two additional low-mass planets, Gliese 367 c and d, in the Gliese 367 system reinforces the idea that ultrashort period planets are often found in multi-planet systems. These newfound companions orbit close to the star but have lower masses, adding complexity to the formation scenarios of Gliese 367 b.

While the exact circumstances leading to the formation of Gliese 367 b remain uncertain, this study highlights the importance of understanding outliers and oddball planets in expanding our knowledge of planetary formation. Gliese 367 b serves as a fascinating case study and raises intriguing questions about the diversity and complexity of exoplanetary systems.

Sources:

– Original article: “We can’t understand nature without understanding its range” by Next Big Future
– Study: “Company for the Ultra-high Density, Ultra-short Period Sub-Earth GJ 367 b: Discovery of Two Additional Low-mass Planets at 11.5 and 34 Days” published in The Astrophysical Journal Letters

Gliese 367 b – An Oddball Ultrashort Period Planet

Gliese 367 b – An Oddball Ultrashort Period Planet

Gliese 367 b – An Oddball Ultrashort Period Planet

Gliese 367 b – An Oddball Ultrashort Period Planet



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