Spectral Class
NOTICE: This page is a Work in Progress as much of the lore/Development for the game is yet to be established.
This page details the Stellar Classification system used in Starship Simulator to categorize stars based on their spectral characteristics, temperature, and luminosity. The game utilizes the real-world Morgan-Keenan (MK) System.
Overview
Stars are classified by a string of characters (e.g., G2V). This code provides a snapshot of the star's surface temperature, its position within a temperature bracket, and its size/brightness (luminosity).
- Letter (O-Y): The Spectral Class (Temperature).
- Number (0-9): The Numerical Sub-class (Temperature precision).
- Roman Numeral (I-VII): The Luminosity Class (Size/Life stage).
Spectral Classes (OBAFGKMLTY)
The primary sequence runs from the hottest (O) to the coldest (Y). A common mnemonic to remember the main sequence is: "Oh, Be A Fine Girl/Guy, Kiss Me, Lovenly Today, Yay."
| Class | Color | Temperature (Kelvin) | Characteristics |
|---|---|---|---|
| O | Deep Blue | > 30,000 K | Extremely hot and massive; very rare and short-lived. |
| B | Blue-White | 10,000 – 30,000 K | Highly luminous; often found in young stellar clusters. |
| A | White | 7,500 – 10,000 K | Common naked-eye stars with strong hydrogen lines (e.g., Sirius). |
| F | Yellow-White | 6,000 – 7,500 K | Slightly hotter and larger than the Sun. |
| G | Yellow | 5,200 – 6,000 K | "Yellow Dwarfs" like our Sun (Sol is a G2V). |
| K | Orange | 3,700 – 5,200 K | "Orange Dwarfs"; Slightly cooler and smaller than the Sun. |
| M | Red | 2,400 – 3,700 K | "Red Dwarfs"; the most common type of star in the galaxy. |
| Extended Classes (Brown Dwarfs) | |||
| L | Deep Red | 1,300 – 2,400 K | Very cool objects; transition between stars and brown dwarfs. |
| T | Magenta/Methane | 700 – 1,300 K | Methane-rich brown dwarfs; emit mostly infrared light. |
| Y | Ultra-Cool | < 700 K | Theoretical "Cold" brown dwarfs; surface temps can be room temperature. |
Numerical Sub-classes (0–9)
Each letter class is divided into ten sub-divisions to provide more detail on temperature.
- 0 is the hottest end of a class.
- 9 is the coolest end of a class.
Example: An A0 star is significantly hotter than an A9 star. Following the sequence, an A9 is only slightly hotter than an F0.
Luminosity Classes (Roman Numerals)
The Roman numeral at the end of the spectral type describes the star's size and "Luminosity." This tells you if the star is a tiny dwarf or a massive supergiant.
- 0 / Ia-0: Hypergiants (Extremely rare and massive)
- I: Supergiants (Ia: Luminous, Ib: Less Luminous)
- II: Bright Giants
- III: Giants
- IV: Subgiants
- V: Main Sequence (Dwarfs) — This is where the Sun and most stable stars live.
- VI: Sub-dwarfs
- D / VII: White Dwarfs (Remnants of dead stars)
Example Breakdown: Sol (Our Sun) G2V
- G: Spectral Class (Yellow, ~5,800 K).
- 2: Sub-class (Hotter end of the G-scale).
- V: Luminosity Class (Main Sequence Dwarf).