The existence of the exoplanet beta Pictoris c, which was already known by an indirect method, is now reaffirmed with the taking of the first direct image, for which the Gravity instrument has been used, in the Chilean Atacama Desert.
The exoplanet, which orbits the star Beta Pictoris 63 light years, it had been detected at first by the radial velocity method, through the spectrum of its star.
Direct images of exoplanets are very rare because it is very difficult to take a picture of a planet alongside their bright host star, which are typically a thousand to tens of billions of times brighter than the planets.
For the direct detection of Beta Pictoris c, the Gravity instrument of the European Southern Observatory (ESO) was used, which combines the light of four eight-meter telescopes and has managed to directly observe the flash of light from the exoplanet.
“It’s amazing, what level of detail and sensitivity we can do it with Gravity, “explains Frank Eisenhauer, the instrument’s lead scientist at the Max Planck Institute.
Direct detection was made possible by radial velocity data, which accurately establish the orbital motion of Beta Pictoris c, allowing the team to pinpoint and predict the expected position of the planet so that Gravity was able to find it.
Astronomers can now combine knowledge of these two previously separate techniques, meaning that can get both gloss and mass of that exoplanet and both measurements combined represent an important step in fine-tuning the planet formation models.
As a general rule, the more massive a planet, the brighterBut, in this case, the data from Beta Pictoris cyb – the other that orbits the star – is somewhat puzzling.
It is estimated that Beta Pictoris c could have eight times the mass of JupiterBut the light coming from him is six times weaker than that of his older brother, who could have a similar mass.
The data that will provide an answer to the unknown mass of Beta Pictoris b will come from the radial velocity method, although it will take time, since the exoplanet takes 28 years to complete one orbit of its star.