This is the first time that heavy metals - elements heavier than hydrogen and helium escape from a "hot Jupiter" type planet, a large, gaseous planet very close to its sun
How can a planet be "hotter than hot?" The answer is when heavy metals are detected escaping from the planet's atmosphere, instead of condensing into clouds.
Observations from NASA's Hubble Space Telescope reveal magnesium and iron in a gaseous state flowing from the strange world known as WASP-121b. This is the first time that heavy metals - elements heavier than hydrogen and helium escape from a "hot Jupiter" type planet, a large, gaseous planet very close to its sun. The WASP-121 system lies about 900 light years from Earth.
Due to the extreme proximity, there is a large difference between the gravitational forces on both sides of the planet causing it to distort and take on the flattened shape of a football. Typically, hot Jupiter-sized planets despite their proximity to their sun still manage to keep their interiors cool enough to condense elements like magnesium and iron.
But WASP-121b, which orbits so close to its sun that the temperature in its upper atmosphere reaches 2,500 degrees Celsius. The temperature in the upper atmosphere of WASP-121b is ten times greater than that of any known planetary atmosphere.
"Heavy metals have previously been seen in other warm planets, but only in the lower atmosphere," explained lead researcher David Singh of Johns Hopkins University in Baltimore, Maryland. "It is impossible to know whether they are escaping the planet or not. In WASP-121b we see magnesium and iron gas at such a great distance from the planet that they appear to have been freed from its gravity.”
|Ultraviolet light from the host star, which is brighter and hotter than the Sun, heats the upper atmosphere and helps these materials escape. "Also, the escaping magnesium and iron gas may contribute to the increase in temperature," said Singh. "These metals will make the atmosphere more opaque in the ultraviolet range, which may contribute to the heating of the upper atmosphere," he explained.
This boiling planet is so close to its sun that it is on the verge of disintegration. Because of this it looks like an American football because of the gravitational tidal forces.
"We chose this planet because it is so extreme," Singh said. "We thought we had a chance to discover escaping heavy elements. It is warm and comfortable for observation. We were mainly looking for magnesium, but there were hints of iron in the atmospheres of other planets outside the solar system, but we were surprised to see it so clearly at such high altitudes so far from the planet. The heavy metals escape in part because the star is so big and bloated that its gravity is relatively weak. As a result, its atmosphere is also constantly being ripped apart by the system's sun.
The researchers used the Hubble Space Telescope spectrograph to look in ultraviolet light for the spectral signatures of magnesium and iron imprinted on the system's main star light filtered through WASP-121b's atmosphere as the planet passed in front of its sun from our point of view.
This planet is also a perfect target for observation by the yet-to-be-launched James Webb Space Telescope, which is planned to search for water and carbon dioxide in infrared light, which can be detected at longer, redder wavelengths. Combining the Hubble observations with those to be made by James Webb will give astronomers a more comprehensive inventory of the chemical elements in the planet's atmosphere.
The WASP-121b planet study is part of the PanCET survey, a program to examine twenty planets outside the solar system ranging from the size of super-Earths (several times the mass of Earth) to the size of Jupiter (100 times the mass of Earth), in a first comparative study between observations of Violet, in the visible light and in the infrared range in large-scale extrasolar planets.
The observations of WASP-121b add to our understanding of how planets lose their primordial atmospheres. When planets form they collect an atmosphere containing gas from the disk where the planet and star formed. These atmospheres consist mainly of primordial, lighter gases, hydrogen and helium, the most abundant elements in the universe. This atmosphere dissipates as a planet approaches its sun.
According to Singh, "The hot Jupiters are mostly composed of hydrogen, and Hubble is very sensitive to hydrogen, and thus we know that these planets can lose the gas relatively easily", said Singh. "But in the case of WASP-121b, the hydrogen and helium gases flow, almost like a river, and drag the metals along with them. It's a very effective mechanism for mass loss on a large scale..”
The findings appeared on the website of the Astronomical Journal
More of the topic in Hayadan:
4 תגובות
Anonymous first:
What you see from a distance of 900 light years happened 900 years ago.
Not 900 billion years and there is no reason to assume it no longer exists.
All the evidence shows that there were no stars and planets 900 billion years ago (nor space or time in the known sense).
May your name be praised forever!
A flat star, an egg-shaped star, a star that is not round but has an irregular shape. Why "football"? Not everyone in Israel knows what football looks like. This is an unfortunate translation.
Why don't you write that what we see is what was 900 billion years ago and actually doesn't exist at all now. dead. Nada zero.