Astronomers use ESO’s ‘Very Large Telescope’ to identify a new exoplanet defying expectations: Digital photography review

Lead image and all other images provided by ESO

The European Southern Observatory’s Very Large Telescope has discovered a new star in the night sky. Astronomers have photographed a planet orbiting b Centauri, a two-star system that you can see with the naked eye. This observation is important because it is the hottest and largest planetary host star system ever found. The planet orbits its star at a distance 100 times that of Jupiter orbiting the Sun.

The researchers published research in nature. The study’s first author, Markus Janson, an astronomer and professor at Stockholm University, explains, ‘Finding a planet around b Centauri is exciting because it completely changes the picture. about the major stars as planetary masters.’

The discovered planet, named b Centauri (AB) b or b Centauri b, is as polar as its environment. The planet is 10 times more massive than Jupiter, making it one of the largest known planets. As mentioned earlier, its orbital distance is also extremely wide. At a distance 100 times greater than Jupiter’s distance from the Sun, b Centauri b’s orbit is one of the widest discovered. The researchers believe that the large distance between the planet and the star pair may be why the planet is able to survive in harsh environments that normally inhibit planet formation.

System b Centauri b, imaged by ESO’s VLT and SPHERE instrument, planet b Centauri b (noted by arrow). Image credit: ESO/Janson et al.

The Centauri b-star system, also known as HIP 71865, is approximately 325 light-years from the constellation Centaurus. With a mass at least six times that of the Sun, the Centauri b system is the most massive system for which a planet has been confirmed. Before it was discovered, the most massive system known had an orbiting planet three times the mass of the Sun.

Massive stars are usually very hot, and the Centauri b system follows this trend. The main star is a B-type star and is three times hotter than the Sun. Due to its high temperature, the main star emits a lot of ultraviolet and X-ray radiation.

The surrounding gas is subject to the effect of large volume and high heat. The surrounding matter evaporates more quickly, which often has an anti-planetary effect. “B-type stars are generally considered to be quite destructive and dangerous environments, so it is believed that it is very difficult to form large planets around them,” said Janson.

Lucio Mayer, professor of computational astrophysics at the University of Zurich and study co-author, said: ‘This large distance from the central pair of stars and the associated reduced radiation may be the key to survival. at the planet. ‘Some evidence suggests that the planet did not form by the common accretion mechanism, in which – put simply – solid objects develop into a planet over time by gradual accumulation. But we still can’t say whether it was formed by the so-called gravitational instability mechanism, in which clouds of matter collapse under their own gravity, or in some other way. ‘

The new discovery offers typical trends and exhibits that stars can form in massive star systems. Co-author Gayathri Viswanath, PhD student at Stockholm University, said, ‘The planet in b Centauri is an alien world in a completely different environment from what we experience here on Earth and in Our Solar System. It’s an extreme, radiation-dominated environment, where everything is on a giant scale: bigger stars, bigger planets, bigger distances. ‘

Sascha Quanz, Professor of Planets and Habitat at ETH Zurich, co-author and NCCR PlanetS member adds, ‘To date, relatively few planets have been discovered around stars with masses greater than two Suns. Thus, previous studies concluded that planet formation is hindered near more massive stars, and that giant planets may not even be able to stay near more massive stars. tree sun. ‘

The discovery was made using the high-contrast Spectro-Polarimetric Exoplanet Research (SPHERE) instrument, mounted on ESO’s VLT in Chile. This is not the first time SPHERE has photographed planets outside our Solar System. It is also used to take the first picture of two planets orbiting a Sun-like star.

Illustration of b Centauri b. Illustration credit: ESO/L. Calçada

However, SPHERE is actually not the first instrument to take pictures of the newly discovered planet. In fact, more than 20 years ago, researchers photographed it with ESO’s 3.6-meter telescope, but it was not yet recognized as a planet at the time.

The researchers hope that with ESO’s Very Large Telescope (ELT) expected to begin observations later this decade and upgrade to the existing VLT, it’s possible to learn more about b Centauri b. . Janson adds, ‘It will be a fascinating quest to try to figure out how it might have formed, which is a mystery at the moment.’

For more information, visit ESO, ETZ Zurich, and nature.