Cannonball-sized Jupiter Discovered With a Density More Than Lead: ScienceAlert

Astronomers have just discovered a cosmic cannonball.

A star about 730 light-years away orbits an exoplanet the size of Jupiter, but with an intensity that boggles the mind. Astronomers have determined that the world, called TOI-4603b, has a mass roughly 13 that of Jupiter.

This means that it is almost 3 times the density of Earth, and just over 9 times that of Jupiter. And it is truly beloved by its star, with a narrow orbit of only 7.25 days.

This places it in a small but important category of worlds that challenge our understanding of planetary formation and evolution. This discovery is accepted for publication in Astronomy and Astrophysics Letters, Available on arXiv prepress server.

It is one of the largest and densest transiting giant planets known to date. Type a team of astronomers Led by Akanksha Khandelwal of the Physics Research Laboratory of India, “and adding value to the fewer than five close-mass giant planets in the high-mass planet and low-mass brown dwarf overlap region, which is also required to understand the processes responsible for their formation.”

Theoretically, there is a limit to how much mass a planet can have. This is because, above a certain critical limit, the temperature and pressure on the core are sufficient to ignite nuclear fusion, the process of smashing atoms together to form heavier elements.

For a star, the minimum mass at which this process begins is about 85 Jupiters. At this point, the hydrogen atoms begin to fuse into helium.

It is believed that the maximum mass of the planet exists 10 to 13 planets. The objects that straddle the gap between them are known as brown dwarfs. These do not contain enough mass for hydrogen fusion. However, its nuclei can fuse with deuterium, a heavy isotope of hydrogen that does not require a great deal of heat and pressure.

Stars form from top to bottom, when a dense clump in a molecular cloud collapses under gravity to form a protostar. The star then grows by absorbing material from the cloud around it, which then forms into a disc.

The dust and gas left after this process form the planets, which start from the bottom up as bits of aggregate begin to stick together, eventually forming clumps that grow into planets.

Brown dwarfs are thought to form like stars, from a mass of molecular cloud that collapses under the influence of gravity. They are usually found orbiting stars at a very great distance, at a minimum of five astronomical units (AU) – five times the distance between Earth and the Sun.

Astronomers believe that they form in a similar way to stars, collapsing a mass of material into a cloud, and there is a wonderful “desert” of close-orbiting brown dwarfs.

TOI-4603b was first spotted in data from the NASA Exoplanet Hunting Space Telescope he-goat, which studies patches of sky looking for faint, regular dips in starlight that indicate the presence of an exoplanet orbiting the solar system. TESS data has suggested a world 1,042 times the radius of Jupiter, orbiting its star in just over a week.

The team went on to search for radial velocity measurements. This is the amount by which an exoplanet’s gravity has moved its host star, as the two objects orbit a common center of gravity. If you know the star’s mass, you can calculate the mass of an exoplanet by calculating how much the star has moved.

This is how the researchers derived a mass for TOI-4603b of 12.89 times the mass of Jupiter. Combining that with the body radius allowed the team to arrive at an average density of 14.1 grams per cubic centimeter. Earth’s density, for example, is 5.51 grams per cubic centimeter. Jupiter is 1.33 grams per cubic centimeter. Lead has a density of 11.3 grams per cubic centimeter.

This isn’t strange at all, for a brown dwarf, which is found in the mean around it 0.83 times The radius of Jupiter is a single brown dwarf with a radius of 0.87 times that of Jupiter, and it has a mass around it 61.6 planets, For example. This stuff can get much more intense than TOI-4603b.

TOI-4603b fits most criteria for classification as an exoplanet, which is what Khandelwal and her colleagues have called it. But it is on the cusp of a brown dwarf’s mass limit, which means it could be an important world for understanding how brown dwarfs and giant planets form, and how their relationship to their stars evolves.

For example, an exoplanet has a significantly elliptical or eccentric orbit, which indicates that it is still settling in. The star also has a companion brown dwarf, orbiting around 1.8 AU, which can interact gravitationally with TOI-4603b. These clues indicate that an exoplanet is migrating closer to the star from a more distant location.

A similar object is a world called HATS-70b, which has a mass of 12.9 times the mass of Jupiter and 1.384 times the radius, is less dense than TOI-4603b, but is similarly close to its star, and is showing signs of migration.

“Discovering such systems” for researchers He writes“It will provide us with gaining valuable insights into the governing mechanisms of megaplanets and improve our understanding of their dominant composition and migration mechanisms.”

Search accepted Astronomy and Astrophysics Lettersand is available at arXiv.