You’re looking at the closest exoplanet ever directly imaged from Earth.
To date, astronomers have catalogued nearly 2,000 extrasolar planets. Of these, a precious few have actually been photographed. That red blotch you see above is now the closest exoplanet for which a direct image and spectrum has been obtained.
Typically, exoplanets are observed indirectly using such techniques as the transit method, or by measuring changes in the radial velocity of host stars. In the vast majority of cases, astronomers aren’t able to detect the light from these planets due to their extreme distance from observational equipment. But VHS J1256b—a gas giant located 40 light-years from Earth—is close enough, bright enough, and distant enough from its host star to be seen and distinguished by our telescopes. The direct image of VHS J1256b, along with its spectral signature, was acquired by scientists at the Institute of Astrophysics of the Canaries (IAC), the Centre of Astrobiology (CAB), and the Polytechnic University of Cartagena (UPCT).
Left : An image of the planet at 100 AU from the dwarf star VHS 1256. This false colour image was compiled from images in the Y J and K bands. Right: Optical and infrared spectra. Image and caption credit: Gabriel Pérez, SMM (IAC).
At about 11 times the mass of Jupiter, this massive planet orbits a red dwarf at a distance of 100 AU, which is about 20 times further than Jupiter’s distance from the Sun. Because VHS J1256b is so far from its host star, the astronomers were able to isolate its full spectral range, including ultraviolet rays, X-rays, and infrared.
This system is quite young, with an estimated age between 150- and 300-million years old, making it about 15- to 30-times younger than our Solar System. It’s possible that this is what Jupiter looked like some 4.2-billion years ago.
“As it is young its atmosphere is still relatively warm, around 1,200 degrees C and it is still sufficiently luminous for us to be able to detect it with the VISTA telescope of the European Southern Observatory (ESO),” noted Bartosz Gauza in a statement. He’s the first author on the paper, which now appears in the Astrophysical Journal.
Artist’s impression of VHS J1256b. Credit: Instituto de Astrofísica de Canarias
The planet’s spectrum was obtained by the Gran Telescopio CANARIAS (GTC) at the Roque de los Muchachos Observatory and the New Technology Telescope (NTT) at the La Silla Observatory.
According to study co-author Antonio Pérez-Garrido from the Polytechnic University of Cartagen: “This study was possible thanks to the software techniques which we have developed in our group and which allowed us to detect, among tens of millions of sources, those which move in the sky, and to pick out those which have companions — in this case a planet orbiting a red dwarf — with a common proper motion”.
The spectral signature of VHS J1256b indicated traces of water vapor and alkali metals, but not methane, which came as a surprise.
Read the entire study at the Astrophysical Journal: “Discovery of a young planetary mass companion to the nearby M dwarf VHS J125601.92-125723.9”.
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