Are there planets that contain life beyond Earth? The answer is maybe, according to a new study from University of Texas at Arlington physicists examining F-type star systems.
Stars fall into seven lettered categories according to their surface temperature. They also differ in other factors, including mass, luminosity, and radius. F-types are in the middle of the scale, hotter and more massive than our sun.
These stars are yellowish-white in colour and have surface temperatures of more than 10,000 degrees.
In the research led by doctoral student Shaan Patel and co-authored by professors Manfred Cuntz and Nevin Weinberg, the physicists presented a detailed statistical analysis of the currently known planet-hosting F-type stars using the NASA Exoplanet Archive.
The archive is an online exoplanet and star data service that collects data for research.
The role of F-type stars in categorising planet habitability
“F-type stars are usually considered the high-luminosity end of stars with a serious prospect for allowing an environment for planets favourable for life,” Dr Cuntz said.
“However, those stars are often ignored by the scientific community. Although they have a shorter lifetime than our Sun, they have a wider HZ.”
Patel added: “F-type star systems are important and intriguing cases when dealing with habitability due to the larger HZs.
“HZs are defined as areas in which conditions are right for Earth-type bodies to potentially host exolife.”
After excluding systems with little information about planets, the team identified 206 systems of interest.
In one case, the planet HD 111998, also known as 38 Virginis, is always situated in the HZ. It is located 108 light-years from Earth and is thus considered to be part of the extended Solar System neighbourhood.
It’s also 18% more massive and has a radius 45% greater than the Sun.
Future uses of the research
“In future studies, our work may serve to investigate the existence of Earth-mass planets and also habitable exomoons hosted by exo-Jupiters in F-type stars,” Patel explained.
Among possible future projects are studies of planetary orbits, including:
- Cases of part-time HZ planets.
- Explorations of the relationships between planetary habitability and stellar evolution, including astrobiological aspects.
- Assessments of exomoons for distinct systems.
Dr Weinberg concluded: “What makes a study like this possible is the hard work and dedication of the worldwide community of astronomers who have discovered more than 5,000 planets over the last 30 years.
“With so many known planets, we can now carry out statistical analyses of even relatively rare systems, such as planets orbiting F-type stars, and identify those that might reside in the habitable zone.”
