Leibniz Institute for Astrophysics Potsdam (AIP) | 2020 Jun 11
Scientists from the Leibniz AIP examined the fate of the young star V1298 Tau and its four orbiting exoplanets. The results show that these recently born planets are roasted by the intense X-ray radiation of their young sun, which leads to the vaporisation of the gaseous envelope of these planets. The innermost planets could be evaporated down to their rocky cores, so that there is no atmosphere left.Artist's impression of the extrasolar planet system around the star V1298 Tau.
Credit: AIP/J. Fohlmeister
Young exoplanets live in a high-stakes environment: their sun produces a large amount of energetic X-ray radiation, typically one thousand to ten thousand times more than our own Sun. This X-ray radiation can heat the atmospheres of exoplanets and sometimes even boil them away. How much of an exoplanet's atmosphere evaporates over time depends on the properties of the planet – its mass, density, and how close it is to its sun. But how much can the star influence what happens over billions of years? This is a question that astronomers at the AIP chose to tackle in their newest paper.
The recently discovered four-planet system around the young sun V1298 Tau is a perfect test bed for this question. The central star is about the same size as our Sun. However, it is only about 25 million years old, which is much younger than our Sun with its 4.6 billion years. It hosts two smaller planets – roughly Neptune-sized – close to the star, plus two Saturn-sized planets farther out. ...
X-ray Irradiation and Evaporation of the Four Young Planets
around V1298 Tau ~ K. Poppenhaeger, L. Ketzer, M. Mallonn
- Monthly Notices of the RAS (online 30 May 2020) DOI: 10.1093/mnras/staa1462
- arXiv.org > astro-ph > arXiv:2005.10240 > 20 May 2020