A new paper suggests that intelligent aliens may need to turn their home stars into natural spacecraft to explore the galaxy and hunt for resources. Several known star systems may be suitable.
The movement of alien civilizations in space and their motivations
An advanced alien civilization might want to travel the galaxy, and the best way to do that is to control its own binary star system, researchers suggest in a new paper.
Long-lived civilizations can have many motives for wanting to move somewhere else in the galaxy. For example, they may need to escape from an impending supernova. Maybe they need to find our new natural resources. Or maybe they just want to explore.
However, given the vast distances between stars, interstellar travel is extremely difficult and time-consuming. So instead of leaving their system, intrepid alien beings may decide to take it with them. The main advantage of speeding up their own star would be that they could keep it with them while traveling. They could do this by making their star radiate or vaporize in only one direction, which would lead the star, along with all its planets, to a new place in the galaxy.
“Hypervelocity stars”
Astronomers have investigated whether “hypervelocity” stars could have been purposefully launched by alien civilizations, but the known candidates show no evidence of artificial intervention.
In a recent paper, Clement Vidal, a philosopher at Vrije Universiteit Brussel in Belgium, pointed out that most stars are not lonely but belong to binary systems. This means we could lose half of the potential artificially accelerated stars. Moreover, binary systems have many advantages over their single counterparts, Vidal writes in his paper, which has not yet been peer-reviewed or published in a scientific journal.
Vidal took a model of a system consisting of a neutron star and a low-mass star orbiting tightly around it. This setup provides the greatest flexibility in control and traction.
Alien civilizations’ way of moving stars
An alien civilization would have to find a way to eject material from the star. This could be due to asymmetric magnetic fields or some device causing uneven heating of the stellar surface. Regardless, the goal would be to get the star to eject more material in one direction than the other. This would create a thrust that would push the binary system in the opposite direction, Vidal explained.
If a civilization placed the equipment on or near a neutron star where strong gravity could provide a ready source of power, they could operate the binary system by carefully turning the vehicle on and off. For example, if they only activated the vehicle at one point in the orbit, they were pointing the binary system in the same direction. If they left the vehicle on a little longer, they corrected their course, steering the movement in any direction along the orbit.
They could even point their system in new out-of-orbit directions by changing the direction the vehicle was pointing, effectively changing the orbit of a neutron star around its companion.
It is surprising that there are real systems in the Universe that fit these characteristics, such as the black widow pulsar PSR J0610-2100 and the red spin pulsar PSR J2043+1711. Both of these systems have significant accelerations. While they are unlikely to be caused by alien technology, they are worth investigating, Vidal concludes. At least while they still exist.
Provided by www.space.com
