Hestia and Sunline
Image from Steve Bowers
Class 3 Sunline around Hestia, in the Iota Piscium system, which provides light and heat to a large number of local moons and habitats.
Artificial sunlight generation systems associated with gas giants, brown dwarfs and main sequence stars, which can be used to focus light onto moons, habitats and even distant planets.

There are three classes of sunline;

Class 1 Sunline

Sunline 2
Image from Steve Bowers
This luminous band in the atmosphere of Kurzweil, a gas giant in the Keter Dominion, provides illumination for the local family of moons. The light is provided by millions of self-supporting fusion units.
Class 1 sunlines, a form of gas giant stellification technology, use self-replicating fusion or conversion reactor units in the atmosphere of a gas giant or brown dwarf to produce a luminous equatorial band. A typical fusion illumination unit will support itself in the atmosphere on a stream of plasma, which will illuminate the surrounding atmosphere; a significant amount of energy can be collected from the luminosity of the fusion drive itself, and converted into a collimated beam that can be aimed towards significant targets.

Fusion Candles
Image from Steve Bowers
Fusion units in the atmosphere of Kurzweil
This causes a thick band of light and heat to be visible around the gas giant (often but not always at the equator; the additional radiance helps the local moons and worldlets to be terraformed in a variety of ways, or provides power for other projects.

Class 2 Sunlines

Sunline- Class 2 (circumstellar)
Image from Steve Bowers
Class 2 stellar sunline around HIP 46761. Light collected from this star by an orbital band is focused onto specific distant targets, such as moons and habitats outside the Habitable Zone.
Class 2 sunlines, known as stellar sunlines, orbit various kinds of star, and collect emitted light from the star's surface and concentrate it into focused beams which can illuminate distant planets in the outer planetary system. This allows even cold outer system objects to be terraformed. The stellar sunline generally orbits in the plane of the equator, and sends collimated beams of light towards the various illuminated objects.

Because the light is concentrated on specific objects, the system is very efficient, and from most angles the sunline is difficult to see against the brilliance of the star itself. But as seen from the target object, a Class 2 sunline will appear to be a small but brilliant line or hoop in the sky.

Class 3 Sunlines

Image from Steve Bowers
Class 3 sunline
Class 3 sunlines: A Class 3 sunline is a hybrid system that incorporates features of both Class 1 and Class 2 sunline design. Like a Class 1 sunline, a Class 3 sunline produces its own energy from local resources, rather than relying on collected starlight. But like many class 2 sunlines, this system uses an orbital ring to support the illumination elements.

Class 3 sunlines orbit various types of gas giant and brown dwarf and use a system of skyhooks and orbital rings or mass streams to extract material from the central body and deliver it to the sunline array. The material is then burned using high efficiency fusion or conversion reactors within the sunline and the resulting energy used to illuminate the moons and habitats in orbit. In most cases illumination is focussed onto specific orbital locations, with the bulk of the system limited to only natural illumination; but in some cases the entire volume is bathed in radiance.
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Development Notes
Text by Todd Drashner and Steve Bowers
Initially published on 14 September 2009.