A hot inflated Jupiter was found orbiting TOI-1789. Astronomers using NASA’s Transiting Exoplanet Study Satellite (TESS) have discovered a hot Jupiter exoplanet in transit around a slightly evolved star called TOI-1789.
Hot inflated Jupiter
An artist’s presentation of the hot Jupiter exoplanet TOI-1789b. Image credit: tips16.com. Hot Jupiter has established several firsts, from being the first type of exoplanet discovered using the radial velocity method (51 pins) to being the first of a type of transiting system studied for precise radii and orbits (HD 209458b), Khandelwal said for aspiration. Astronomers from the Indian Institute of Technology and Physics Research Laboratory and their colleagues.
These systems have intrigued theorists, prompting a significant overhaul of planet formation theories. Two theories have been used more commonly to explain nearby giant planets: in situ formation by gravitational instability or core accretion, followed by inward migration, he said.
Gravitational instability hypothesizes the formation of giant planets through fragmentation into conjoined groups of protoplanetary disks. In the case of core accretion, the giant planet forms several astronomical units (AU) beyond the so-called ice line where there is enough solid material to form the core, and then migrates inward.
“The migration is caused by proto-planetary disk torque or by gravitational scattering due to a third body. This can reduce the orbital separation of the planet from its formation location of several AUs to one hundredth of AU.”
TOI-1789 is a slightly evolved metal-rich late F-type star located 729 light-years distant in the constellation Leo. Also known as HD 82139, TIC 172518755, TYC 1962-00303-1, and 2MASS J09305841 + 2632246, the star is 2.8 billion years old, about 2.2 times more massive than the Sun and 1.5 times more massive.
“TYC 1962-00303-1 is a relatively bright star in the northern celestial hemisphere, first cataloged as TOI-1789 on March 12, 2020,” the astronomers said. This source was observed by TESS between January 21 and February 18, 2020, with an interval of 2 days due to data transfer from the spacecraft.
High precision radial velocity observations were obtained from the high resolution spectrograph at the Physics Research Laboratory in India, PARAS and TCES at Thüringer Landesternvaart Teutenberg in Germany. The new planet TOI-1789 orbits once every 3.2 days at a distance of 0.05 AU.
Designated TOI-1789b, the planet has a mass and radius of 0.7 and 1.4 times that of Jupiter, and an apparent density of 0.31 g / cm3. This places TOI-1789b in the category of an inflated hot Jupiter. Only 8 exoplanets have been discovered so far, including TOI-1789b, which are housed in stars similar or more evolved than TOI-1789 and orbit much closer to their host star (less than 0.05 AU), the researchers said.
Despite the rarity of hot Jupiters in slightly evolved stars in close orbits, TOI-1789b is completely “non-anomalous”, satisfying most evolutionary models. Detecting similar exoplanets will help us improve our understanding of the distribution, formation, and migration of hot Jupiters around rising stars. The team article has been submitted for publication in Monthly Notices of the Royal Astronomical Society.
Astronomers discover the youngest known hot Jupiter. Using data from NASA’s Transiting Exoplanet Study Satellite (TESS) and the Spitzer Space Telescope, astronomers have discovered a hot transiting planet Jupiter orbiting a very young star called HIP 67522.
An artist’s impression of a hot Jupiter exoplanet. HIP 67522 is a G0-type star located approximately 417 light-years distant in the constellation Centaurus. Also known as HD 120411, 2MASS J1350627-4050090, and TYC 7794-2268-1, this star is a member of a young group of stars called the Scorpius-Centaurus Association.
HIP 67522 is about 17 million years old, which means that the hot new Jupiter is only a few million years younger. Called HIP 67522b, the planet orbits the star once every 7 days and is about 10 times the diameter of Earth, or closer to Jupiter.
Astronomer Aaron Rizzuto of the University of Texas at Austin and his colleagues detected the signature of the alien world in the TESS data. They then used archival data from the Spitzer Space Telescope to confirm that the transit signal was from a planet. We can learn a lot about our solar system and its history by studying the planets and other things that orbit the Sun, said Dr. Rijuto.
But we will never know how unique or common the Solar System is, unless we are looking for exoplanets. Exoplanet scientists are exploring how our solar system fits into the larger picture of planet formation in the universe.
According to astronomers, there are three main hypotheses about how Jupiters get so close to their parent stars. One is that they just come and stay there, he explained. But it’s hard to imagine planet formation in such an intense environment. Not only will the scorching heat vaporize most of the material, but young stars often explode with massive explosions and stellar winds, potentially saving emerging planets.
The gas giants appear to have evolved far from their parent star, beyond a boundary called the snow line, where it cools enough to form ice and other solids. Planets like Jupiter are made up almost entirely of gas, but they have solid cores. It would be easier for those cores to move beyond the ice line, where the frozen material could clump together like a growing snowball.
The other two hypotheses assume that this is the case and that hot Jupiters are approaching their stars. But what will be the reason and the moment of migration! He said one view holds that hot Jupiters begin their journey early in the history of the planetary system, while the star is still surrounded by the disk of gas and dust from which it and the planets formed.
In this scenario, the gravity of the disk interacting with the planet’s mass can disrupt the gas giant’s orbit and cause it to migrate inward. The third hypothesis says that hot Jupiters approach their star later, when gravity from other planets around the star can drive migration.
The fact that HIP 67522b is already so close to its host star after its formation indicates that this third hypothesis probably does not apply in this case. But a hot, young Jupiter isn’t enough to settle the debate over how they all form, the researchers said. The discovery has been published in the Astronomical Journal.