‘Ultra-hot Jupiter’ has heavy metals in its atmosphere
Observations of an exoplanet that is hotter than many stars uncovers a glowing sky of iron and titanium
Iron and titanium have been found in the atmosphere of a planet outside our Solar System for the first time. The heavy metals were detected around KELT-9b, a gas giant 620 light years from Earth, made possible because it also happens to be the hottest exoplanet discovered so far.
Thanks to an equilibrium temperature of 3,700 degrees Celsius (6,692 degrees Fahrenheit), clouds do not condense in the atmosphere. This means the atoms around KELT-9b are not trapped within other molecules and are allowed to fly on their own in their atomic form, better enabling their detection.
Researcher Kevin Heng, who wrote of his observations of the findings in a blog post, says iron and titanium “have long been an ingredient in the theory of exoplanet formation, but they have never been directly detected”. This discovery is able to shed greater light on how planets are formed and why some objects become stars and others gas giants. While there is no chance of discovering life on KELT-9b, the technique used to observe iron and titanium could prove useful for other studies.
Heng told All About Space that the technique – which involved examining light from the exoplanet as it passed directly in front of its star – could also be used to detect biosignatures, signs of life.
“On Earth, we think it's oxygen and a few other obscure molecules,” he says, “but we don't know what biosignatures are in general. If you knew what they were… you could use exactly the same technique to detect these molecules in cooler, smaller planets.”