Scientists searching for life as we know it on alien worlds typically focus on planets around stars like our own G-type sun. And some scientists believe that life can also develop on planets orbiting smaller, cooler stars. But a recent study suggests that alien life could flourish on worlds around hotter stars too.
A paper published in the International Journal of Astrobiology asserts that scientists should not limit their exploration for life to stars similar to our sun. University of Texas at Arlington physics professor Manfred Cuntz, the paper’s co-author, explained to Astrobiology Magazine,
It has been argued that the most likely host candidates for exobiology should be K-type or even M-type stars based on their relatively long life spans and high frequency compared to the other types of main sequence stars . . . But the only case known for life to exist is the environment of our sun, identified as a relatively hot and massive G-type star . . . Therefore, it appears to be fully appropriate to explore the possibility of exobiology for stars even hotter and more massive than the Sun.
F-type main sequence stars have approximately ten to sixty percent more mass than our sun, and have a surface temperature ranging from 10,500 to 12,500 degrees Fahrenheit (in comparison to our sun’s surface temperature of approximately 10,000 degrees Fahrenheit).
Although the scientists involved with this study surmise that F-type stars are likely at the upper range of where life can survive, they believe that these solar systems once considered inhospitable could be prime candidates for habitability. As the Daily Mail reports, “The study suggests beings on a planet in orbit around an F-type star would receive up to 7.1 more radiation damage than we receive on Earth. But an atmosphere or ocean could provide sufficient protection to allow the alien life to survive.” Yes, too much radiation is bad. But Cuntz explains, “Broadly speaking, UV should be considered both a friend and a foe to the principal possibility of life. At the present stage of Earth in regard to many of its life forms, the lack of an ozone layer would be truly harmful to most types of surface life. On the other hand, in regard to life’s origin and early stages of evolution, a notable UV intensity could be important for facilitating the onset of life by triggering relevant early-stage biochemical reactions.”
Another promising aspect of F-type stars, as the Daily Mail points, is that their solar systems could have larger habitable zones, providing more planets that might have liquid surface water.