My planet - let's call it Penumbra for now - exists at roughly 1.5 AU from it's sun - which was similar to Earth's - but is about a billion years older.
It is 15% more massive than Earth, but nearly identical in size.
It has around 85% of the atmospheric pressure.
It has an axial tilt of 13.5 degrees +/- 2 degrees, giving it minor seasonal changes.
Its rotation is equivalent to 40 hours, and its orbit is 450 of their days.
In the distant past the planet and solar system were home to a very advanced nonhuman race. As their planet underwent runaway greenhouse effects and their star began heating up, they built a large space construct at the L1 point - a magnetically stabilized plasma mirror with a frequency tuned to reflect all light above indigo-violet – designed to cool their planet. It was built to be fully automated and self-repairing. It’s powered by a ring of solar stations and has arrays capable of beaming light to Penumbra. Currently, they are tuned to emit infrared and ultraviolet light at levels necessary to maintain preset environmental conditions on the planet’s surface.
Due to this, the day/night cycle at the equator is roughly 18 hours of Truenight, 6 hours of Zenith, 10 hours of Falsenight, and 6 hours of Apogee. Zenith and Apogee are the periods where the Sun is not blocked entirely by the Mirror – Falsenight is when the mirror is blocking most or all sunlight and only ultraviolet/violet/indigo/infrared light is reaching the surface.
The race that set this up was also capable of modifying wholly or in part most species of plants, so plants that do most of their photosynthesizing during the 6 hour periods of light or have been modified to utilize UV/indigo.
Question: Given the fiction of the plasma mirror, is this planet as described realistic?
- Do not consider moons as I haven't settled on what moon(s) the planet would have.