There was a recent discovery of a 3 solar mass non-interacting black hole with a red giant companion with a mass of half that, below is a link to the article:
https://news.osu.edu/black-hole-is-closest-to-earth-among-the-smallest-ever-discovered/
This gives me an idea for an artificial world we can call "Mega-Earth" because 3 solar masses equals one million Earth masses, and at a radius 1000 times that of Earth (12,800,000 km) the gravity which would be 1,000,000g at 1 Earth radius, gets reduced to 1g at 1000 Earth radii due to the inverse square law, and because the surface area of a sphere is proportional to the square of its radius, it will have one million times the surface area of Earth or one third of the surface area of Larry Niven's Ringworld. This is a huge sphere, a kind of shell World and it is orbited by a red giant of 1.5 solar masses which can provide surface illumination. I'll go check the Scouts book to find a suitable star for this.
The closest giant I can find on the charts is an Orange Giant K0 III, it has 4 solar masses and a Luminoscity of 95 times that of the Sun, this places the habitable zone at around 9.75 AU from the star the orange giant has 1 more solar mass than the black hole, and it needs a circular orbit around the common baricenter. Because the shellworld has such a large radius, its day is 24 Earth days long so a point on its surface gets 12 days of daylight followed by 12 days of night.
The orbit period is 4202 days and 11 hours, or about 11.5 years. If the planet has seasons, each season is 2.88 years long.
https://news.osu.edu/black-hole-is-closest-to-earth-among-the-smallest-ever-discovered/
This gives me an idea for an artificial world we can call "Mega-Earth" because 3 solar masses equals one million Earth masses, and at a radius 1000 times that of Earth (12,800,000 km) the gravity which would be 1,000,000g at 1 Earth radius, gets reduced to 1g at 1000 Earth radii due to the inverse square law, and because the surface area of a sphere is proportional to the square of its radius, it will have one million times the surface area of Earth or one third of the surface area of Larry Niven's Ringworld. This is a huge sphere, a kind of shell World and it is orbited by a red giant of 1.5 solar masses which can provide surface illumination. I'll go check the Scouts book to find a suitable star for this.
The closest giant I can find on the charts is an Orange Giant K0 III, it has 4 solar masses and a Luminoscity of 95 times that of the Sun, this places the habitable zone at around 9.75 AU from the star the orange giant has 1 more solar mass than the black hole, and it needs a circular orbit around the common baricenter. Because the shellworld has such a large radius, its day is 24 Earth days long so a point on its surface gets 12 days of daylight followed by 12 days of night.
The orbit period is 4202 days and 11 hours, or about 11.5 years. If the planet has seasons, each season is 2.88 years long.
