The atmosphere of any planet can tell a lot about it. Apart from the obvious question of whether the planet can support life or not, it can identify various other properties that can help us understand the said planet better. Therefore, it is not a surprise that when astronomers find a new exoplanet, they want to study its atmosphere as well. We have some extraordinary instruments that can be used to find out what an exoplanet is like. However, this does not mean that it is an easy job.
Researchers recently found an extraordinary exoplanet named LTT 9779b. The exoplanet lies 260 light-years away from Earth. After it was discovered about a month ago, naturally, follow up studies were conducted. The exoplanet is bigger than Neptune and orbits a sun-like star. However, it is peculiar in two ways; first, it orbits its star extremely closely. Its orbit time is only 19 hours. Second, despite its proximity to its star, the exoplanet has a substantial atmosphere. The researchers thought that it would be impossible to maintain an atmosphere so close to a star because of the extremely high temperatures; however, it seems like they were wrong.
The planet is at a temperature of 3,000 degrees, which is enough to vaporize any atmosphere that it may have instantly. Despite this, the spitzer telescope has picked up infrared light that indicates that the atmosphere is present. By studying the infrared light coming from LTT 9779b, researchers can figure out many things about the temperature profile of the exoplanet. One thing they found interesting was that the hottest time of the day on the exoplanet was noon. On Earth, It is a little while after noon because Earth absorbs heat faster than it radiates it back.
What this means is that the exoplanet is reflecting most of the incident heat out. The absorbed heat is also not transported to the night side of the planet. This means that the upper atmosphere absorbs most of the heat, making it possible to radiate it back so easily. After a little further probing, the researchers found that the planet has Carbon Monoxide, which is not uncommon for hot planets. Researchers previously thought that gravity of a planet of this size would not sustain an atmosphere under such conditions.
It seems like a lot of assumptions from researchers have been broken by this single discovery. While we do know a lot about the exoplanet, we must find out with certainty what causes such unconventional phenomena.