Using the ESPRESSO instrument on ESO’s Very Large Telescope and the HARPS instrument on ESO’s La Silla 3.6-meter telescope, astronomers discovered the hot Saturn-sized gas giant exoplanet WASP-49Ab, which is close to but slightly synchronized. Detected a sodium cloud with a shifted position.
This artist’s concept depicts a volcanic exomoon that could exist between WASP-49Ab (left) and its parent star. Image credit: NASA/JPL/California Institute of Technology.
WASP-49A is a faint sun-like star discovered in 2006 by the Wide Angle Planet Survey (WASP).
The star, also known as 2MASS 06042146-1657550, is located in the constellation Lepus, about 635 light-years from Earth.
The transiting Saturn-mass companion star, WASP-49Ab (also known as WASP-49b), was discovered in 2012 in a 2.8-day orbit.
“Both WASP-49Ab and its star are composed mostly of hydrogen and helium, with trace amounts of sodium,” said Caltech astronomer Apurva Oza.
“Neither of these contain enough sodium to cause clouds, and the clouds appear to be coming from sources that are producing about 100,000 kg of sodium per second.”
“Even if stars and planets were able to produce that much sodium, it is unclear what mechanism would allow them to emit sodium into space.”
Oza and his colleagues found some evidence to suggest that the cloud was produced by another object orbiting WASP-49Ab, but additional research is needed to confirm the cloud’s behavior. .
For example, their two observations showed that when the cloud was not next to the planet, it suddenly increased in size, as if it had been refueled.
They also observed that the clouds were moving faster than the planets. This seems impossible unless the clouds are generated by another object that moves independently and faster than the planet.
“We think this is very important evidence,” Dr. Oza said.
“The cloud is moving in the opposite direction that physics tells it should go if it were part of the planet’s atmosphere.”
Astronomers have demonstrated that this cloud is located above the planet’s atmosphere, similar to the gas clouds that Io produces around Jupiter.
They also used a computer model to explain the exomoon scenario and compared it to data.
WASP-49Ab orbits the star every 2.8 days with clock-like regularity, but the cloud appears and disappears behind the star and planet at seemingly irregular intervals.
The researchers used a model to show that exomoons with eight-hour orbits around the planet sometimes appeared to move in front of the planet or did not appear to be associated with certain clouds. It was shown that it is possible to explain the movement and activity of clouds, such as how they move. region of the planet.
“The evidence that something other than a planet or star is producing this cloud is very convincing,” said Dr. Rosalie Lopez, a planetary geologist at NASA’s Jet Propulsion Laboratory.
“The detection of an exomoon is highly unusual, but thanks to Io we know that volcanic exomoons are possible.”
of findings Published in Astrophysics Journal Letter.
_____
Apurva V. Oza others. 2024. Redshifted sodium transient near an exoplanet transit. APJL 973, L53; doi: 10.3847/2041-8213/ad6b29
Source: www.sci.news
