A team of astronomers used data from TESS and the Spitzer space telescope to analyze the atmosphere of a distant planet called LTT 9779b.
The planet is known as “hot Neptune,” and the study marks its atmosphere’s first thorough analysis.
The Discovery
The researchers discovered that the emission spectrum is significantly different from the bigger “hot Jupiters” scientists analyzed in the past.
Ian Crossfield, an assistant professor of physics and astronomy from the University of Kansas, claims that the team studied, in a scientific premiere, the light coming from a planet that theoretically shouldn’t even exist.
According to Crossfield, the planet is so intensely irradiated by the star it orbits that its temperature is more than 3000 degrees Fahrenheit.
Heat should have evaporated the planet’s entire atmosphere, but Spitzer’s observations reveal it has an atmosphere thanks to the planet’s infrared light emitted.
LTT 9779b doesn’t present a solid surface due to surface temperatures a lot higher than Mercury in our solar system. The surface temperatures are so hot that elements like lead, platinum, chromium, and stainless steel would melt in the planet’s atmosphere. A whole year on that planet is less than 24 hours on Earth.
The planet was discovered one year ago, and it was one of the first Neptune-sized planets observed by the TESS project.
Researchers from the project used an analysis known as the “phase curve” to figure out the atmosphere’s composition.
Crossfield says that the team determined how the planet emitted much infrared light during each 360-degree rotation along its axis.
Infrared light shows the temperature and the hotspots of a planet.
It turned out that the planet is the hottest at noon and most infrared light comes from the area of the planet is straight overhead, with significantly reduced heat emission from other parts.