“51 Eridani is only 20 million years old, a little more massive than our sun – a ideal target”, says James Graham, a professor at UC Berkeley and Project Scientist for GPI. “40 million years after the dinosaurs died out”, noted Eric Nielsen, a postdoctoral researcher at Stanford University and the SETI Institute, in a news release announcing the discovery.
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“This is the first time that we directly detected an exoplanet whose atmosphere and distance to its star is similar to that of the giant planets of our own system”, said Julien Rameau, researcher at iREx and UdeM.
Metchev adds, “And more data from the European Space Agency’s Herschel Space Observatory reveal that 51 Eridani is also surrounded by a more distant and colder cometary belt, much like the Kuiper Belt of comets beyond Neptune in the Solar System”.
The image you see above has been created in a very rudimentary way to demonstrate the size of the planet 51 Eri b within our own solar system. The light from the central star has been mostly removed to enable the detection of the exoplanet one million times fainter.
Gas giants in our solar system formed by building up a large core over a few million years and then pulling in huge amounts of hydrogen and other gases to form an atmosphere. “I was like ‘This is awesome, this is incredible”‘. “We actually see the planet as a distinct dot and measure its properties, like its atmospheric spectrum, or its temperature”, study author Bruce Macintosh, a professor of physics at Stanford University, tells The Verge.
51 Eri b is the first previously unknown planet found by a new generation of instruments designed to increase the number of direct sightings. And it couldn’t have been discovered with any other existing instrument. Scientists more commonly search by looking for the drop in starlight that occurs when a planet pases in front of, or transits, the face of a star. Kepler is also best at finding planets very close to older, dimmer stars – ones that complete an orbit just once every few days.
The “young Jupiter” found by the Gemini Planet Imager (GPI) orbits the star 51 Eridani, 96 light years from Earth, and has an atmosphere rich in methane.
Simulated fly-by of the 51 Eridani star and planet system from Franck Marchis.
The team plans to begin observing the planet again in late September, when it emerges from behind the Sun, and hope to find that the planet has moved along its orbit: confirmation that it is, in fact, a planet.
For now, the researchers will work on studying the new planet’s orbit and better pinning down its chemical makeup, as well as keeping an eye out for more planets within the system. “What GPI does is referred to as direct imaging”.
The new planet is also the first planet detected by the Gemini Planet Imager (GPI). For example, it can look for chemical signatures for compounds like methane in the different colours of light coming from a planet.
Scientists have discovered a Jupiter-like planet in a young solar system that could help us gain insight into planet formation in our own neighborhood. Those all had dusty, star-like atmospheres with barely any detectable methane.
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“This planet really could have formed the same way Jupiter did – this whole planetary system could be a lot like ours”, Macintosh said in a statement. As such, the exoplanets directly imaged until now were large, weighing at least five Jupiters. Scientists don’t even yet know if there are other planets orbiting the same star as 51 Eridani b. 51 Eri is one of 600 young stars within about 300 light-years of Earth that the Gemini Planet Imager is slated to analyze in the next three years. He has been working on the Gemini Planet Imager project for 10 years and was part of the team that used the instrument to discover a planet for the first time.
