New technique for spotting Dyson rings unveiled

Dyson spheres and rings have always held a special fascination for me. The concept is simple: build a great big structure either as a sphere or ring to harness the energy from a star. Dyson rings are far more simple and feasible to construct and in a recent paper a team of scientists explore how we might detect them by analyzing the light from distant stars. The team suggests they might be able to detect Dyson rings around pulsars using their new technique.

Like their spherical cousins, Dyson rings remain for now, a popular idea in science fiction yet they are starting to appear more and more in scientific debates. The concept of the ring is similar to the sphere, a megastructure designed to encircle a star, harnessing its energy on a gargantuan scale.

It might consist of a series of satellites or even habitats in a circular orbit with solar collectors and unlike the spheres, require far less resources to build. The concept of the sphere was first proposed by physicist and mathematician Freeman Dyson in 1960. Such structures might be detectable and reveal the existence of intelligent civilizations.

It’s fascinating to think about civilizations building such constructions. Our own civilization currently consumes around 15,000 terawatts per hour and that number is only going to increase as our population grows and we become even more reliant on technology. To endeavor to quantify the energy usage from the level of technological capability, the Kardashev scale was developed.

On this scale, we are currently at Type I which means our power usage is 4 × 10¹⁹ erg s¹ (4 terawatts) If a civilization requires 4 × 10³³ erg s¹ (400 trillion terawatts) then it is considered to be type II and it is these civilizations that may be capable and indeed it may be necessary to build Dyson structures.

To create either a solid sphere or even a sphere with orbiting satellites would require phenomenal amounts of material. A sphere which had a radius of 1 astronomical unit (the average distance between Earth and the sun) would require more material than exists in the entire solar system.

It is far more likely that civilizations would create ring structures. Rings of this nature around a star would be able to harness significant amounts of energy but a ring around a pulsar would, if the pulse beam of the star could be tracked, be able to capture even more energy, of the order of 10 thousand trillion terawatts.

In the paper written by Ogetay Kayali from Michigan Technological University and team, they propose further exploration of pulsar light curves to see if features that could reveal their presence have been missed. The features the team suggest arise from effects of the pulsar beam striking the ring structure. The beams travel at superluminal speeds which could result in multiple images of the pulsar spot on the Dyson ring appearing simultaneously. This may be visible in light curve analysis. A similar effect is seen when dust rings are illuminated with pulsar radiation.

The research is accepted for publication in Monthly Notices of the Royal Astronomical Society.