Some 60 light-years away from Earth, in the Milky Way’s Pictor constellation, lies a giant super-Jupiter that goes by the name of Beta Pictoris b. This particular exoplanet is quite famous — it has been studied extensively, due to its proximity to our planet, and it’s actually one of the first planets to be found through direct imaging.
Spotted in 2009, Beta Pictoris b is a behemoth 3,000 times more massive than Earth and weighing about 13 Jupiter masses, the Inquisitr previously reported.
But while astronomers thought this exoplanet was completely unique, it turns out it has a doppelganger with the same mass, brightness, and spectrum, Science Daily reports.
Described in a new study that awaits publication in The Astronomical Journal, this recently discovered doppelganger has been given the name 2MASS 0249 c and seems to be an identical twin of Beta Pictoris b — by all measures, save one.
The two exoplanets are alike in all ways except for how they came to be. And, since they have different origins, they can’t actually be considered twins.
“We have found a gas-giant planet that is a virtual twin of a previously known planet, but it looks like the two objects formed in different ways,” said study lead author Trent Dupuy, an astronomer at the Gemini Observatory in Hawaii.
— Brad Hast (@BradHast) July 17, 2018
The team stumbled upon the exoplanet doppelganger with the help of the Canada-France-Hawaii Telescope (CFHT) on Hawaii’s Big Island.
“To date, exoplanets found by direct imaging have basically been individuals, each distinct from the other in their appearance and age,” said study co-author Michael Liu, astronomer at the University of Hawaii’s Institute for Astronomy. “Finding two exoplanets with almost identical appearances and yet having formed so differently opens a new window for understanding these objects.”
The first series of observations uncovered that the two exoplanets were born in the same stellar nursery and orbit stars belonging to the same beta Pictoris moving group.
But the parent stars, strikingly different from one another, have spawned their planets in completely distinct conditions, which means that 2MASS 0249 c is not an exact replica of Beta Pictoris b.
What Sets Apart These Apparent ‘Twins’
As previously reported by Inquisitr, Beta Pictoris b revolves around a massive young star known as Beta Pictoris. This stellar parent is about 1.8 times more massive than our sun — and 10 times brighter.
Meanwhile, 2MASS 0249 c orbits and binary system made up of two brown dwarfs, which don’t boast the same kind of energy as Beta Pictoris and are actually 200 times fainter than the sun.
Two identical planets discovered in two different star systems. Researchers discovered that #exoplanet 2MASS 0249 c is like a twin to exoplanet beta Pictoris b. They have the same brightness,same light spectrum and the same mass.
— GinGo (@GinGoResearch) July 19, 2018
In fact, this brown dwarf binary, picked up by the W. M. Keck Observatory in Hawaii, “is one of the few ultracool binaries to be discovered in a young moving group and the first confirmed in the Beta Pictoris moving group,” the study authors wrote in their paper, currently available on the pre-print server arXiv.
Another major difference between Beta Pictoris b and its exoplanet doppelganger is that it orbits its parent star a lot closer. The exoplanet circles Beta Pictoris as a distance of about nine astronomical units (AU) — where 1 AU is defined as the distance between Earth and the sun.
Its Doppelganger’s situation couldn’t be more disparate, as 2MASS 0249 c is found at a staggering distance of 2,000 AU from the brown dwarf binary.
All these circumstances have ensured that the two seemingly identical exoplanets formed through different processes. Beta Pictoris b likely coalesced from tiny dust grains and grew by accumulating gas from the star’s disk, whereas 2MASS 0249 c — which “looks like an underweight brown dwarf,” according to study co-author Kaitlin Kratter — sucked in gas directly from the original stellar nursery where the parent stars were formed.
“2MASS 0249 c and beta Pictoris b show us that nature has more than one way to make very similar looking exoplanets,” says Kratter, who astronomer at the University of Arizona in Tucson.