By Will Dunham
WASHINGTON (Reuters) – The planet known as HD 189733b, discovered in 2005, already had a reputation as a pretty extreme place, a scorching gas giant a little bigger than Jupiter that is a striking cobalt blue and rains glass melt that blows sideways in its ferocious atmospheric winds. So how can you overcome this?
Add hydrogen sulfide, the chemical compound behind the stench of rotten eggs. Researchers said Monday that new data from the James Webb Space Telescope is providing a more complete picture of HD 189733b, already one of the most studied exoplanets, as planets beyond our solar system are called. A small amount of hydrogen sulfide was detected in its atmosphere, a first for any exoplanet.
“Yes, the stinky smell would certainly add to its already infamous reputation. This is not a planet we humans want to visit, but a valuable target for deepening our understanding of planetary science,” said astrophysicist Guangwei Fu of Johns University Hopkins in Baltimore. lead author of the study published in the journal Nature.
It’s a type called “hot Jupiter” – gas giants similar to the largest planet in our solar system, only much hotter due to their proximity to their host stars. This planet orbits 170 times closer to its host star than Jupiter does to the Sun. It completes an orbit every two days, as opposed to the 12 years that Jupiter takes for one orbit around the Sun.
In fact, its orbit is 13 times closer to its host star than our innermost planet, Mercury, is to the Sun, leaving the temperature on the star-facing side of the planet at about 930 degrees Celsius (1,700 degrees Fahrenheit). ).
“They are very rare,” Fu said of hot Jupiters. “About one in every 100 star systems has them.”
This planet is located 64 light years from Earth, considered to be in our neighborhood within the Milky Way galaxy, in the constellation Vulpecula. A light year is the distance light travels in one year, 5.9 trillion miles (9.5 trillion km).
“The close distance makes detailed studies brilliant and easy. For example, the detection of hydrogen sulfide reported here would be much more challenging on other distant planets,” Fu said.
The star it orbits is smaller and cooler than the Sun, and only about a third as luminous. This star is part of a binary system, which means it is gravitationally bound to another star.
Webb, which will become operational in 2022, observes a broader wavelength range than previous space telescopes, allowing for more complete examinations of exoplanet atmospheres.
“Our research found that HD 189733b is more similar to Jupiter than previously known,” said Luis Welbanks, an astrophysicist at Arizona State University and co-author of the study. “This planet is a lot like Jupiter, but just hotter.”
Jupiter also has traces of hydrogen sulfide in its atmosphere. This planet is about 10% larger than Jupiter in diameter and mass.
In addition to detecting hydrogen sulfide, a molecule that contains sulfur, Webb’s observations showed that this planet has water and carbon dioxide in its atmosphere, as previous data also indicated.
“With these three molecules, we can count the amount of oxygen, carbon and sulfur that the planet has, giving us the opportunity to understand how the planet may have formed and whether or not it is different from the planets in our solar system,” , Welbanks said.
Webb’s observations also ruled out the presence of methane in the planet’s atmosphere.
“Understanding the composition of this and other exoplanets allows us to understand how unique our solar system is and helps us contextualize our existence,” added Welbanks.
“Although we are not looking for life on HD 189733b – it is too hot, composed mainly of hydrogen and helium, not like Earth, etc. – understanding its atmosphere allows us to understand how physics and chemistry behave in different environments and start putting together the ‘recipe’ to form planets.”
(Reporting by Will Dunham, Editing by Rosalba O’Brien)
