‘Terbium’ detected in the 4300°C atmosphere of the hot planet ‘KELT-9b’, the heaviest element in the atmosphere | Sorae Portal site to space

The type of planet that was discovered for the first time in the history of observation as an exoplanet orbiting a star other than the Sun is “Hot Jupiter“Is. The gaseous planets in the solar system are farther from the Sun than Earth, so they are in a cold environment, but it is not uncommon for hot Jupiters, which orbit close to their stars, to have surface temperatures of more than 1,000 degrees Celsius … as he suggests.” In the name, hot Jupiters experience extreme temperatures, and the environment is considered extremely harsh.

Gas giants like Jupiter and Saturn are thought to have rocky cores hidden deep in their thick atmosphere. As such, the components of gas giants’ atmospheres are mostly hydrogen and helium, and no rocky or metallic elements are usually present.

However, in the case of hot Jupiters, which are heated to high temperatures, a very strong atmospheric circulation occurs, so rocks and mineral elements also appear on the surface. The heavier the element, the less the amount that was originally present in the planet, and the less likely it is that it will rise from the core to the sky, making it more difficult for it to appear on the surface.

A research team such as NWB Borsato of Lund University, one of Jupiter’s hot planets”KELT-9band looked for metallic elements in the atmosphere.

KELT-9b, located about 670 light-years from Earth,One of the hottest exoplanets with a maximum surface temperature of 4300°CHe is. It is known from previous observations that KELT-9b’s atmosphere, heated to a temperature higher than the surface temperature of a cold star, has very unusual properties like that of a hot Jupiter. For example, molecules such as water and carbon dioxide do not exist because they are decayed by the intense radiation from stars. On the other hand, metallic elements such as iron and titanium have already been discovered. A closer look at KELT-9b’s atmosphere may also reveal other metallic elements.

-B-

Borsato et al. KELT-9b was observed using the HARPS-N spectrometer at the Roque de los Muchachos Observatory and the CARMENES spectrometer at the Caral Alto Observatory. (both Spanish observatories). Both instruments specialize in spectroscopy corresponding to the Doppler effect caused by planetary motion, and have an excellent performance in examining the atmospheric composition of hot Jupiter.

Observation result, 8 kinds of metallic elements (※ 1) It was found, but the most amazing discovery among them was “terbium」 (※ 2) And the”barium」 (※ 3) He is. Terbium was first detected in the atmosphere of an exoplanet. This is the third case of barium, but the first two cases (WASP-76b and WASP-121b) were discovered in 2022 and are extremely rare.

Terbium is element 65 and barium is element 56, and they are the two heavy elements found in the atmospheres of exoplanets. It is currently unknown whether the mechanism that lifts such heavy elements from the depths of the planet can be explained by simple atmospheric circulation alone, or whether other mechanisms are at work.

Work on the composition of the hot Jupiter’s atmosphere provides clues for exploring normally inaccessible regions of the gas giant’s deep interior. The mechanisms that lift the heavy elements will also provide clues to the details of the material cycles within the planets. KELT-9b’s observations may not only detect trace elements in the atmosphere, but also provide important clues to the details of the planet as a whole.

* 1 … calcium, titanium, vanadium, chromium, nickel, strontium, barium, terbium

-B-

*2: An element that belongs to a group of similar elements called rare earths. It is used as a crystal stabilizer for fuel cells operating at high temperatures, as a special alloy that expands and contracts with magnetism, and as a green fluorescent agent.

* 3: One of the alkaline earth metals. The most prominent application is as a contrast agent (the so-called “barium porridge”) which takes advantage of the hard-to-pass-through properties of x-rays. In addition, it has been shown in materials that are expected to be used practically in the future, such as pyrotechnics that use a green flame reaction, ceramics that exhibit piezoelectric effects, and high-temperature superconductors.

source

• NWB Borsato et al. “Mantis Network. III. Expanding the frontiers of chemical searches within ultrahot Jupiters: new discoveries of Ca I, VI, Ti I, Cr I, Ni I, Sr II, Ba II and Tb II in KELT-9b”. (Astronomy and astrophysics) (arXiv)
• Nicholas Borsato. “Scientists Detect Rare Element in Exoplanet’s Atmospheres”. (Lund University)
• Azevedo Silva and others. “Detection of barium in the atmospheres of the superhot gas giants WASP-76b and WASP-121b”. (astronomy and astrophysics)

Text: Rare Aya