Could Eelong exist in real life?

[Mitchz95]

There was a book series I read when I was younger called Pendragon. One of the books took place on an Earth-like world called Eelong which, instead of a normal sun, had a bright band (called a "sunbelt") that stretched from the northern horizon to the southern one, and still had a normal day/night cycle. Obviously it's not hard sci-fi, but I was wondering if something like that could actually exist in the real world somewhere.

Perhaps the planet orbits a pulsar, and the sunbelt is the bright beam of radiation that constantly spews from its poles. Is there are scientific basis to this? Any place I could experiment with the concept?

[lajoswinkler]

Neutron star suroundings are not only eliminated of matter due to the supernova that created it, but also constantly bombarded by intense ionizing radiation. Nothing could survive there.

[boolybooly]

If it was the accretion disc of a blackhole the planet would have to orbit in the same plane as the accretion disc or the sun band would become a circle every orbit.

If the planet rotated so that the sun band rose and set stretching north to south then the axis of planet rotation would need to be parallel with the direction of orbit around the black hole. Due to gyroscopic effect this would mean the planet would end up pointing each pole at the black hole every orbit around it so that would not physically work.

So maybe the jets of a black hole would produce some lateral emissions and that would work, but the planet would need a thick atmosphere and heavy magnetic field or be very distant from the jets to avoid being cooked by them and the accretion disk, which would necessarily form a bright patch in the middle of the sunband.

So my feeling is it would need to be an artificial structure created around a planet which had lost its original sun. Possibly a circular ring in a polar orbit which has light emitting elements which switch off/on as they pass the poles so that only one half of the ring is lit at any one time.

Another possible alternative is a planet sitting in a Lagrangian L2 point where it is in permanent eclipse but a sphere of billions of orbiting mirrors on polar orbits at slightly different altitudes are able to reflect light from outside the eclipse cone onto the planet surface. The mirrors would need to be cylindrical and the axis of the cylinder perpendicular to their orbit of the planet so that as the planet and eclipsing body rotate around the star the sphere of mirrors would continue to reflect light from the band of mirrors which was facing perpendicular to the path of light from the star. The altitudes or timings for the mirror orbits would need to be very close because they would need to pass into the eclipse cone at the poles to prevent excess night time lighting. But the poles would in any case be in eternal light due to the nature of the described sunband. 

 

2c

[p1t1o]

Im not sure if this really pans out, but it was the first thing I thought of when I read the OP:

There is a phenomenon called a "starbow" which is theorised by some people to be what you would see if you were travelling close to the speed of light. Light coming from in front of you would be blue-shifted, probably out of the visual spectrum, light coming from behind would be similarly red-shifted, around you at the mid-point, you get the so-called "starbow" a bright band of un-blue-or-red-shifted light (just regular stars basically). If you were perhaps travelling through the galactic nucleus where stars are very densely packed, this "starbow" might resemble what is described, a "sun-band", if your planet was travelling through this region close to the speed of light. As the planet rotated on its axis, the band would appear to rotate around the planet.

Im not sure but I think the "starbow" effect might not be universally supported and possibly you would see something else, and even if it worked out it might not be enough to be a "sun".