55 Cancri E – Super-Earth planet scientists think is likely made of diamond

A recent study done by Nikku Madhusudhan, a Yale postdoctoral researcher in physics and astronomy, Yale geophysicist Kanani Lee, and Olivier Mousis, a planetary scientist at the IRAP suggests a surface of a nearby super-Earth planet is covered in graphite and diamond. This planet is twice the size of earth and eight times of its mass, making it a super-Earth, according to Yale news post.

The diamond planet, named 55 Cancri E, is among five planets orbiting a sun-like star 55 Cancri located 40 light years from earth in the constellation Cancer, this star is visible even to the naked eye. Talking about its orbital speed, it completes a revolution of the star in just 18 hours as compared to earth’s 365 day and 6 hours. It is fiercely hot, having temperature of about 3900 degrees Fahrenheit and therefore uninhabitable at all. Project’s lead researcher Nikku Madhusudhan, a Yale postdoctoral researcher in physics and astronomy said,

“This is our first glimpse of a rocky world with a fundamentally different chemistry from Earth. The surface of this planet is likely covered in graphite and diamond rather than water and granite. It’s the first time we know of such an exotic planet that we think was born mostly of carbon-which really makes this a fundamental game-changer in our understanding of what’s possible in planetary chemistry.”

Discovered last year while transiting its star, astronomers had measured its radius. Now after collecting more data, research team deduced planet’s chemical composition by using models of its interior and by computing all possible combinations of elements and compounds that would yield those specific characteristics. Research suggests that planet has no water at all and is composed primarily of carbon (as graphite and diamond), iron, silicon carbide, and, possibly, some silicates. According to study’s estimate, at least a third of the planet’s mass could be diamond, which is equal to thrice the mass of earth.

According to David Spergel, professor of astronomy and chair of astrophysical sciences at Princeton University, who is not a co-author of the study,

“Stars are simple — given a star’s mass and age, you know its basic structure and history. Planets are much more complex. This ‘diamond-rich super-Earth’ is likely just one example of the rich sets of discoveries that await us as we begin to explore planets around nearby stars.”

Madhusudhan, Yale geophysicist Kanani Lee, and Olivier Mousis, a planetary scientist at the Institut de Recherche en Astrophysique et Planetologie in Toulose, France authored this paper. Findings of the study will be published in Astrophysical journal letters, titled “A Possible Carbon-rich Interior in Super-Earth 55 Cancri e” as per Yale news. The research was supported by the Yale Center for Astronomy and Astrophysics (YCAA) in the Yale Department of Physics through Madhusudhan’s YCAA postdoctoral prize fellowship.

Featured image: Image by Haven Giguere/Yale news