There’s a Planet With a 27,000 Year Orbit, and That’s Just the Beginning

An international team of astronomers has discovered two strange exoplanets in a star system 1,200 light-years from Earth. Using a Transit Method and Direct Imaging to detect the two exoplanets, they were very surprised at what they found. One of the exoplanets has an orbital period of less than 11 days around its sun, whereas the other exoplanet takes a staggering 27,000 Earth years to orbit the same star.

Astronomers using the Transit Method detected the first of the two exoplanets, CVSO 30b back in 2012. The planet is roughly believed to be six times the size of Jupiter and has an orbital distance of 1.2 million kilometers from its parent star, taking CVSO 30b less than 11 days to complete one full orbit.

The star CVSO30, showing the two detection methods that revealed its exoplanet candidates. Credit: Keck Observatory/ESO/VLT/NACO

In contrast, international astronomers using the Keck Observatory in Hawaii, the ESO’s Very Large Telescope in Chile, and the Spanish National Research Council’s (CSIC) Calar Alto Observatory, found the second of the two exoplanets, CVSO 30c in remote regions around its parent star with a orbiting distance of 666 astronomical units (1 AU = 9.296x107 miles). CVSO 30c is also several times the mass Jupiter, yet it takes the planet 27,000 years to complete one orbit.

Lead author of the paper that described the initial findings, Tobias Schmidt from the University of Hamburg, the Astrophysical Institute and University Observatory Jena, told Universe Today via email:

“[30b and 30c] are both unusual on their own. CVSO 30b is the first transiting planet around a star as young as 2.5 million years. Published in 2012, all previously detected transiting planets were older than few hundred million years… It has been a surprise to find a planetary mass companion at 662 AU, or 662 times the distance from Earth to the Sun, from a primary star having only about 0.4 solar masses. According to the standard model, planets form in disks around the star. But none of the observed disks around such low-mass stars is large enough to form such an object.”

An artist's conception of a T-type brown dwarf. (Credit: Tyrogthekreeper under a Wikimedia Commons Attribution-Share Alike 3.0 Unported license).

What is strange is that both exoplanets are several times the mass of Jupiter and both are still very young — less than 10 million years old — it’s not something astronomers would have expected to observe, planets with similar masses but very different orbiting periods.

Since astronomers started to discover exoplanets in remote star systems, we have come to learn that our universe can be extremely diverse, and there is still much we don’t understand. For now, let’s wait on the next discovery of an exoplanet to see what it will have in store.