Building Systems

= The Habitable Zone = The Habitable Zone of your system are the zones in which an environment, naturally suitable for life, can lie without being either to hot or to cold.

The majority of planetary massed bodies have between 1/6 and 3/4 albedo. Although some go as low and as 10% - 90%. While on the other hand Atmospheres vary drastically. For the following assumptions we will assume between 0.17 - 0.75 Albedo and 10% to 10 Times earths atmosphere.

Carbon/Aqua Habitable Zone
Around a star the mass of ours, the habitable zone is assumed to lie between 0.61 AU with 10% or less atmosphere and/or 0.75 or greater albedo - 2.53 AU with 1,000% atmosphere or more and/or 0.17 albedo or less. This is to keep between 273 K and 373 K

Methane
Around a star the mass of ours, the habitable zone is assumed to lie between 6.71 AU with 10% or less atmosphere and/or 0.75 or greater albedo - 23.16 AU with 1000% atmosphere or more and/or 0.17 albedo or less. This is to keep between 91 and 111 K

Sulfur/Ammonia
Around a star the mass, of ours the habitable zone is assumed to lie between 1.46 AU with 10% or less atmosphere and/or 0.75 or greater albedo - 4.71 AU with 1,000% atmosphere or more and/or 0.17 albedo or less. This is to keep between 201 K and 239 K

Planet Temperature Calculator (indiana.edu) was used for the calculations, I did not necessarily get their permission, but I found it on the web so here it is.

= Building Brown Dwarfs = A Brown Dwarf is an object in the grey area between planet and star, They range between 12 and 91 Jovian (♃) Masses. A Brown Dwarf is defined as any body sufficiently massive enough for fusion, but not massive enough for sustained protium fusion. A brown dwarf would still be considered one even if it no longer undergoes fusion.

Sub Classifications
Brown Dwarfs can be classified into three categories


 * Category A: are classified as type-T Dwarfs, They have a mass of between 12 and 66 ♃ and are the lighter type of brown dwarf, the smallest are even lighter than planets.
 * Category B: are classified as type-L Dwarfs, They have a mass range between 64 and 84 ♃ and are the heavier mass of brown dwarf.


 * Category C: are classified as type-M Dwarfs, They has a similar mass range to L type brown Dwarfs with 59 - 89 ♃ but are instead in the M spectrum, these are the most massive of brown Dwarfs and according to some the least massive of stars.

Building Brown Dwarfs
Brown Dwarfs have similar galactic densities to stars with ratios of ~2:3 - 3:2 assumedly, this is just a recommendation and purely speculative.

As mentioned the absolute lightest you can go is 12 Jovian-Masses or JM. And the heaviest is 89 JMs. The radius of your dwarf will be that of Jupiter ± 10%, the more massive the body the smaller the radius

$$R = 1.2-{1.015^M\over 10} $$Here is a unnecessarily overcomplicated formula you can use, if you do not want to be creative with the radius. Where R is the radius of your brown dwarf in JRs and M is the mass of your brown dwarf in JMs.

Building Brown Dwarf Systems
Brown Dwarfs can replace Stars in star systems, Planets orbiting stars, or Planets in Planet systems.

A Brown dwarf will almost always be massive enough that it shares a barycenter with a star outside of the actual star making it a de facto binary.

= Building the Nighttime Sky = When mapping out the nighttime sky it is important to first know where and how bright nearby stars are. Remember no single star beyond 5,000 light years is important even if its has 25,000,000 Solar luminosities more than 4 times the most luminous star known to man, which means you only need to know the stars in your galaxy. For the purposes of this article we will be using a unit known as Lambdas, Λs, or Lams. The unit is roughly 0.340 Watts per square kilometer, and is equivalent to the luminosity of the sun at one lightyear.

To get a stars brightness in lams simply divide its Luminosity (L) in solar watts (3.828e+26 Watts) by the Distance (D) in light years (9.4607e+12 Kilometers) with the distance raised to the second power or $$\Lambda = \frac{L}{D^2}$$One Lam is worth 1,000 las or λs for easier math

The same can be applied to galaxies. Take the total luminosity of the galaxy and divided by distance to the second.

Now rank each star expressed in lams from your. For reference the faintest star visible to the human eye is about 0.1 - 0.2 las or 0.00016 Lams

Apparent magnitude 0.0 ~0.22 W/km or 647 las, Every +5.0 is 100 times weaker, each -5.0 is 100 times stronger.