Q&A: An Earth-like planet with two suns?

This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: A nearby star system with two suns could potentially support an Earth-sized planet in a region where liquid water could exist, according to a new paper examining the dynamics of the system. The paper, published in The Astrophysical Journal, focuses on a binary star system called 70 Ophiuchi.

It is trillions of miles from Earth but is considered relatively nearby in cosmic terms, at about 5 parsecs away. For reference, the nearest star to our sun, Proxima Centauri, is 1.3 parsecs away. 70 Ophiuchi's two stars are slightly smaller and cooler than the sun, at about 88% and 73% of its mass. Though astronomers have observed the system for decades, there are no confirmed planets orbiting either star.

Using observations performed at the University of Michigan to better define how the two stars move around each other, researchers modeled whether an Earth-sized planet could maintain a stable orbit in the habitable zone around the larger star. The habitable zone, or HZ, is the area around a star where a planet is just warm enough that it could maintain liquid water on its surface. Skylar D'Angiolillo, a UC Riverside doctoral student in Earth and planetary sciences, conducted the dynamical modeling for the paper, using computer simulations to see how objects in space move and affect one another over time.

Here, D'Angiolillo and her adviser, UCR astrophysicist Stephen Kane, talk about what the results mean for the search for worlds capable of hosting life. It's a binary system, so there are two stars. We have decades of observational data on the system, including measurements that tell us about the motion of the stars.

Using those data, we were able to better constrain the architecture of the system and model what might happen to a planet there. We calculated the boundaries of the habitable zone around the primary star. Then I tested whether an Earth-mass planet could maintain a stable orbit at different distances within that zone.

What we found is that stable orbits are possible in the habitable zone of the primary star. You might expect the second star to disrupt those orbits, but that isn't necessarily what happens. Kane: This is also one of the nearest star systems to us.