Water detection in the atmosphere of a habitable exoplanet

2019/09/12 Galarraga Aiestaran, Ana - Elhuyar Zientzia Iturria: Elhuyar aldizkaria

• Astrofisika

In the last decade, both from Earth and from space, it has been proven that water is a very common element in the atmosphere of gas exoplanets. But astrophysicists were looking for what they have announced now, a rock exoplanet with water in the atmosphere.In fact, along with temperature and other factors, water is one of the main keys to consider a habitable exoplanet. Finally they find it: The atmospheric spectroscopic study of the planet K2-18 b has confirmed the presence of water.

The study was published in the journal Nature Astronomy. The planet was discovered in 2015 with the Hubble telescope. In fact, they could not see him live, but they knew him thanks to his eclipse of passage between his star and Earth. Analyzing eclipses, they concluded that it is 22 million kilometers from its star, 15% of the distance Earth-Sun. The star is 110 light-years from Earth in the constellation of Leo. It is a red dwarf with a surface temperature of 3,200 °C (the Sun has 5,500 °C). Thus, the planet is in a habitable area, according to researchers.

The diameter of the exoplanet is twice that of the Earth and the mass eight times that of the Earth. And, according to the research, there is no doubt that in its atmosphere there is water vapor. There is also hydrogen and helium, and they believe there may be methane and nitrogen.

Although this is the first time they have found water in an exoplanet, it will certainly not be the last. In fact, they have advanced that the TESS space telescope expects to detect numerous exoplanets.