Stellar System Generation System

Planetary Data Generation System | Standards & Measures

FOREWARNING: This generation system can be rather long and drawn-out. However, if you do not want such information, then just skip the step.

GMs NOTE: Yes. Besides the very basics, I actually studied the data and created this system to do nothing more than to create the Mardona Stellar System, the system of which Udava is an intricate part. How many GMs out there would go to this depth just to create a technically feasible or viable campaign world?

IMPORTANT NOTE: This document will not print out in Portrait setting or the Landscape setting. The best advice is to Right-Click the Luminosity-Radius and Luminosity-Mass Diagrams and save them. Then use your favorite graphics program to print it out, forcing it fit on one page. For printing this document, simply choose this link: Printer.

1) Name

Well this is easy. If you ain't thought of the name, then ponder it, bounce it on the floor, throw it to the walls, stick it to the ceiling. Think. Nothing more can I offer in help, except think and ponder on the name you wish to give the stellar system. Examples: Sol (our stellar system), Mardona (the Udavan stellar system), Arkanjul, Vigatath, etc.

2) Spectral Class

Spectral Class helps to determine many other factors of the stellar primary in question. Simply roll a d100, high open-ended to determine the stellar primary's Spectral Class. A stellar primary's Spectral Class runs from hottest to coldest: W, O, B, A, F, G, K, M, N, R, S, D. Understandably, I have arbitrarily added the Spectral Classes of N, R, S, & D. These four classes do not exist. I made them up. GMs NOTE: I apologize for any misunderstanding. However, for the Multiverse of Udava, N, R, S, & D Spectral Classes do exist.

Another way of looking at N, R, S, & D Spectral Classes is N = nearly dying, R = really dying, S = surely dead, and D = dead. Of these new four classes, D is nothing more than a star that has completely depleted its fuel, leaving nothing more than a cold ball of carbon and iron and some other heavier elements. R & S classes still have some fuel burning; however, that fuel is burning very deep within the core, thus they only glow in the infrared range. N Spectral Class stars still glow with visible light; however, compared to M class stars, they are still very dim and dull.

NOTES
1. Brown Dwarf is a stellar primary similar to a Gas Giant except it is many times more massive. Basically, a Brown Dwarf never ignited a fusion fire.
2. White Dwarf is the remains of a Subdwarf to Subgiant Type stellar primary after it has gone through the Red Giant stage and novaed.
3. Pulsar is very similar to a White Dwarf except it has two equatorial poles which fire out extremely powerful radio waves. This causes the Pulsar to act like a lighthouse beacon.
4. Neutron Star is the remains of a stellar primary that has collapsed but did not have enough mass to collapsed into a Black Hole. Basically, once a Neutron Star burns out, it will be a ball of Pure Neutronium. A substance so dense, a sugar cube sized fragment weighs more than the Earth.
5. Special is any number of astronomical phenomena. Such can include Black Holes, Quasars, Nebulae, Cosmic Strings, Wormholes, Quantum Filaments, Quantum Singularities, Spatial Rifts, Temporal Rifts, Quantum Tunnels, Dimensional Rifts, Universal Rifts, and R, S, & D Spectral Class star, etc.

3) Stellar Type

Stellar Type is the size class of the stellar primary.

4)Temperature Rating

Use 3d10, reading as d1000. Read "0" as zero, producing a result of 000-999.

The above temperatures are listed in Kelvins (K). To convert into Celsius (C): C = K - 273.15. To convert into Farenheit (F):
F = ((K - 273.15) × 1.8) + 32.
Other conversions: C = (F - 32) ÷ 1.8; F = (C × 1.8) + 32.

Surface Temperature Determination
1. Subtract Temperature Rating from 1000.
2. Divide result by 1000.
3. Multiply result by Difference in above table.
4. Add result to Minimum Temperature in above table.
5. Final result is the stellar primary's Surface Temperature in Kelvins.

5)Luminosity Rating

Use the Luminosity-Radius diagram. Find the stellar primary's Spectral Class and Temperature Rating at the bottom. Go upwards until you intersect the stellar primary's Stellar Type curve. Luminosity is on the right. Luminosity is listed in terms of × Sol. Multiply result by 384.6 to find Luminosity in Joules/second.

A better for determining the stellar primary's Luminosity is by using the below equation:

Equation for Object's Luminosity:
where L = Luminosity in Joules per second (J/s); σ = Stefan-Boltzmann constant (5.67 × 10-8); T = object's temperature in degrees Kelvins; R = object's radius in meters

For use with the Texas Instruments TI-30X IIS calculator: .

6) Stellar Radius

Use the Luminosity-Radius diagram. Find the stellar primary's Spectral Class and Temperature Rating at the bottom. Go upwards until you intersect the stellar primary's Stellar Type curve. Radius is on the right along the diagonal lines. Radius is listed in terms of × Sol. Multiply result by 6.96×10⁸ to find Radius in meters.

SPECIAL NOTE: Stellar primaries do not have to be exactly on the curves in the Luminosity-Radius and Luminosity-Mass diagrams. The curves only depict the largest percentage, and stellar primaries may be slightly off the curve. Use common sense, but don't go really overboard.

AUTHOR's NOTES: Both the Luminosity-Radius and Luminosity-Mass Diagrams were painstakingly created back in the days when there was only Windows 3.1 and its lousy Paintbrush program. Basically, I had found equations that calculated these numbers and pixeled each intersection point on a very large graph. These pixeled points did not create a perfect curve. Some gaps were left for me to "best guesstimate." However, this graph did allow those who have not studied Celestial Mechanics and Astrophysics to use "percentages" of the actual values to determine "actual" values. Another good thought, save the below graphic and use it for calculating "percentages" such as a Luminosity equal to ×10^5.15984372. Let's just say it took me months to calculate and pixel each point. How many other GMs would torture themselves so? Of course, I went back and changed the white background so as to ease the refraction pain.

Figure 1: Luminosity-Radius Diagram

Here is the above graphic with a white background. Right-Click, then Save Picture As…

7) Stellar Mass

Use the Luminosity-Mass diagram. Find stellar primary's Luminosity on the left, go right until intersect the curve. Mass is at the bottom. Mass is listed in terms of × Sol. Multiply result by 1.9891×10³⁰ to find Mass in kilograms.

SPECIAL NOTE: Stellar primaries do not have to be exactly on the curves in the Luminosity-Radius and Luminosity-Mass diagrams. The curves only depict the largest percentage, and stellar primaries may be slightly off the curve. Use common sense, but don't go really overboard.

AUTHOR's NOTES: Both the Luminosity-Radius and Luminosity-Mass Diagrams were painstakingly created back in the days when there was only Windows 3.1 and its lousy Paintbrush program. Basically, I had found equations that calculated these numbers and pixeled each intersection point on a very large graph. These pixeled points did not create a perfect curve. Some gaps were left for me to "best guesstimate." However, this graph did allow those who have not studied Celestial Mechanics and Astrophysics to use "percentages" of the actual values to determine "actual" values. Another good thought, save the below graphic and use it for calculating "percentages" such as a Luminosity equal to ×10^5.15984372. Let's just say it took me months to calculate and pixel each point. How many other GMs would torture themselves so? Of course, I went back and changed the white background so as to ease the refraction pain.

Figure 2: Luminosity-Mass Diagram.

Here is the above graphic with a white background. Right-Click, then Save Picture As…

8) Volume

Equation for Object's Spherical Volume:

For use with the Texas Instruments TI-30X IIS calculator: (4×π×(Radius^3))÷3.

Volume Determination
1. Cube radius in meters.
2. Multiply result by π.
3. Multiply result by 4.
4. Divide result by 3.
5. Final result is the Volume in cubic meters.

9) Mean Density

Equation for Object's Mean Density:

For use with the Texas Instruments TI-30X IIS calculator: M/V.

Divide the stellar primary's Mass in kilograms by its Volume in cubic meters. Result is Mean Density in kilograms per cubic meter (kg/m³).

10) Hypershunt Gravity Well Radius (HGWR)

This radius is the distance any vessel utilizing the hypershunt drive must be from the stellar primary in order to hypershunt. The percentage amount within this radius is the percentage chance the vessel will be destroyed when hypershunting. The hypershunt drive is the only drive that suffers this drawback.

To determine the HGWR, simply multiply the stellar primary's Mass in terms of × Sol by 1.4. The result is the HGWR in Astronomical Units (AUs). Multiply this result by 1.496×10⁸ find the HGWR in kilometers.

11) Description

Description is the appearance, or color, of the stellar primary. Main color is highlighted in yellow with adjectives later.

12) Number of Orbital Paths

If result is Companion Star, determine Companion Star's parameters, then reroll on above table. Maximum number of Companion Stars is two (total of three). If so desired, you may simply reroll a result of 96-00.

13) Ecosphere Radii

Although it may not be entirely accurate, the method I devised is rather simple. Take the sum of the Primary's Luminosity Rating, Surface Temperature, and Mass in terms of × Sol. If Companion Stars exist, then also add their Luminosity Rating, Surface Temperature, and Mass. Multiply this result by 0.25 and 1.75. These results are innermost and outermost radii in AUs in which planets may support life. One close to the innermost radius will be hot while one close to the outermost will be cold.

Example: In our system, the above method would compute Ecosphere Radii of 0.5 AUs and 3.5 AUs. These radii would include Venus, Earth, Mars, and the Asteroid Belt. Of course, if there were a planet at the Asteroid Belt, it would be an artic wasteland. Possibly uninhabitable, but then again, it may be like living on Antartica.

14) Eccentricities

An Eccentricity is a captured planet (or other stellar object) which wandered into the stellar system and was caught by the gravity well of the primary. Captured objects will have orbital planes tilted askew out of the stellar system's normal orbital planes. Primary's Mass listed below is in terms of × Sol. For Companion Stars, add the Masses together.

Eccentricity Determination
• First Roll: open-ended d100 + primary's Mass + 30. If 101+, then there is an eccentricity and go to Second Roll.
• Second Roll: open-ended d100 + primary's Mass + 20. If 101+, then there is a second eccentricity and go to Third Roll.
• Third Roll: open-ended d100 + primary's Mass + 10. If 101+, then there is a third eccentricity.

Either choose which orbits are eccentricities, or determine them randomly.

Orbital Inclination
• Roll open-ended d100.
• Result is the Orbital Inclination in degrees.

15) Empty Orbits

An Empty Orbit is where a planet either never formed or escaped the primary's gravity well. Empty Orbits are determined exactly as Eccentricities above, except do not add primary's Mass. Of especial note, an empty orbit can be used to construct base stations.

NOTE: If so desired, you may skip this step and use the Type determination in the Planetary Data Generation System.

16) Companion Star

If desired, you may just simply choose not to have any Companion Stars. Use the Spectral Class table to determine the Companion Star's Spectral Class. Also, use the below modifiers to the roll.

To save yourself some rolling and rerolling on the Spectral Class table, you can just simply choose a Companion Star's Spectral Class equal to one Class lower than the Hottest Companion Class Allowable. For a second Companion Star, choose a Class two Classes lower. Otherwise, you can roll and reroll until you get within the hottest allowable Class.

17) System Resources

This step is determined after all planetary data is known. Generally, can be listed as "poor," "average," "extremely high," etc.

Planetary Data Generation System | Standards & Measures

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