View source for The Galaxy In Detail

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This page details the large-scale structure of the simulated [[Milky Way]] galaxy within [[Starship Simulator]]. The [[Galaxy Generation]] system creates a realistic, 1:1 scale representation of our home galaxy, incorporating distinct structural components and a wide variety of celestial objects that influence the distribution and types of stars players encounter. <span style="color:red;">All items on this page are either implemented into the game or have been referenced in the game in the [[Dev Builds| list of Development Builds]], the [[Roadmap]] or mentioned in Development streams or other sources. Please check the [[Dev Builds| list of Development Builds]] for the most up-to-date information regarding their implementation.</span>

== Overall Structure ==
The simulated galaxy models the known structure of the Milky Way, primarily consisting of:
* a central '''[[#Galactic Core|Galactic Core]]''' housing the supermassive black hole, [[Sagittarius A*]]
* a dense '''[[#Galactic Bulge|Galactic Bulge]]''' surrounding the core
* a flattened '''[[#Galactic Disc (Thin & Thick)|Galactic Disc]]''' containing spiral arms, where most star formation occurs
* a vast, spherical '''[[#Galactic Halo|Galactic Halo]]''' encompassing the disc and bulge
* numerous '''[[#Globular Clusters|Globular Clusters]]''' scattered primarily throughout the Halo and Bulge
* extended structures like stellar streams may also be represented

== Galactic Regions ==
The [[Galaxy Generation]] process defines distinct galactic regions. These regions influence the characteristics of generated star systems.

=== Galactic Core ===
*'''Description:''' the innermost region, centred on [[Sagittarius A*]] (located at galactic coordinates 0,0,0 in the simulation - [[Dev Builds|Build 0.225.0.14]])
*'''Characteristics:''' features extremely high stellar density and contains the supermassive black hole [[Sagittarius A*]], which is rendered as a unique volumetric object ([[Dev Builds|Build 0.225.0.16]]). Navigation near the core presents challenges due to high gravity and radiation.

=== Galactic Bulge ===
*'''Description:''' a dense, roughly spheroidal region of stars surrounding the Galactic Core
*'''Characteristics:''' high star density (less than the core). Contains a mix of older and younger stars. [[#Globular Clusters|Globular Clusters]] are concentrated here and in the Halo.
*'''Simulation Influence:'''high star density. Contains predominantly older [[Star types]].

=== Galactic Disc (Thin & Thick) ===
*'''Description:''' The flattened, rotating structure containing the galaxy's spiral arms. It comprises:
**'''Thin Disc:''' Where most current star formation takes place. Contains younger stars (Population I, like [[Sol]]), open clusters, gas, and dust concentrated along the spiral arms.
**'''Thick Disc:''' A more diffuse, older component surrounding the Thin Disc.
*'''Characteristics:''' Moderate to high star density, particularly within spiral arms. Rich in heavier elements. [[Sol]] is located within the Thin Disc.
*'''Simulation Influence:''' Contains a mix of [[Star types]], with younger, hotter stars more common in the Thin Disc/spiral arms. Star density varies based on the underlying [[Galaxy Generation#Galaxy Structure & Stellar Distribution|density map]].

=== Galactic Halo ===
*'''Description:''' A vast, roughly spherical region extending far beyond the visible disc and bulge. Includes inner and outer halo distinctions.
*'''Characteristics:''' Very low star density. Dominated by very old, metal-poor stars (Population II), often found in [[#Globular Clusters|Globular Clusters]].
*'''Simulation Influence:''' Lowest star density. Primarily older, cooler [[Star types]]. Parameters like Oort Cloud size (derived from Hill Sphere / Tidal Truncation Limits) depend on the galactic region, likely differing significantly in the Halo ([[Dev Builds|Build 0.225.0.67]]).

=== Globular Clusters ===
*'''Description:''' Dense, gravitationally bound collections of hundreds of thousands to millions of very old stars.
*'''Characteristics:''' Found mostly orbiting within the [[#Galactic Halo|Halo]], with some associated with the [[#Galactic Bulge|Bulge]]. Contain Population II stars.
*'''Simulation Influence:''' Represent localized areas of extremely high stellar density within the otherwise sparse Halo or the Bulge.

== Simulated Celestial Objects ==
The [[Galaxy Generation]] system populates these regions with a diverse range of celestial objects:

=== Implemented / Generated Object Types ===
* '''[[Star types|Stars]]:'''
** Main Sequence Classes (O through M).
** Low-Mass Classes: L, T, Y Stars ([[Dev Builds|Build 0.225.0.16]], 0.225.0.24).
** Evolved/Unusual Types: T-Tauri, Wolf-Rayet Stars ([[Dev Builds|Build 0.225.0.16]]).
** Star Remnants: White Dwarfs (DA2 type for [[Sirius]] B), Neutron Stars, Black Holes (including [[Sagittarius A*]]) ([[Dev Builds|Build 0.225.0.16]], 0.225.0.27, 0.225.0.31).
** Includes support for 80 stellar sub-classes (O0V to Y9) for temperature/luminosity variations ([[Dev Builds|Build 0.225.0.30]]).
* '''Planetary Bodies:'''
** Planets (Generated via the System-Gen process, including Rocky subtypes like Earth Analogue, Water World, Lava World; Gas Giants/Ice Giants, including specific types like '''Hot Jupiters''' (Gas Giants orbiting very close to their star); [[Dev Builds|Build 0.225.0.32])).
** Icy Bodies / Dwarf Planets (Generated in Kuiper Belt analogues; specific [[Sol System]] examples like Eris, Sedna added - [[Dev Builds|Build 0.225.0.67]]).
** Rogue Planets (Groundwork laid - [[Dev Builds|Build 0.225.0.16]]).
* '''Star Clusters:''' Globular Clusters and Open Clusters (part of galactic structure).
* '''Other Structures:''' Proto-Planetary Disks (simulated during system generation - [[Dev Builds|Build 0.225.0.32]]). Planetary Rings (generated based on probability - [[Dev Builds|Build 0.225.0.74]]).

=== Planned Future Expansion ===
The following object types and phenomena are planned for future implementation or refinement:
* Moons (also mentioned in [[Roadmap]] 0.226)
* Multi-star systems
* Comets
* Asteroids (also mentioned in [[Roadmap]] 0.227)
* Volumetric Planetary Rings
* Volumetric Gas Giants
* Planetary Nebulae
* Real World Nebulae
* Oort Clouds
* Wormholes
* Additional [[Star types|Stellar Classes]]

== Regional Influence Summary ==
The [[Galaxy Generation]] system uses these defined galactic regions (determined as part of the generation process) to influence:
* '''Star Density:''' The number of stars generated per cubic light-year varies dramatically, driven by a large-scale density map. Densities range from 0 to 8,000 stars per 100ly³ sector.
* '''[[Star types|Star Types]]:''' The prevalence of different spectral types, ages, and metallicities changes based on the region's typical stellar population.
* '''System Parameters:''' Factors used in procedural generation, such as stellar Hill Sphere / Tidal Truncation limits (affecting Oort Clouds), are influenced by the galactic region ([[Dev Builds|Build 0.225.0.67]]).

== Navigation & Exploration ==
Understanding the galaxy's structure and the types of objects found within different regions can aid players in navigation and exploration. Searching for specific types of stars or phenomena, anticipating navigational challenges near the core, or reaching sparsely populated areas involves understanding these large-scale structures and distributions.

=== Galactic Coordinates ===

The game uses a three-dimensional Cartesian coordinate system (X, Y, Z) to precisely define locations within the galaxy. Understanding how these coordinates work is fundamental for players to navigate the vast simulated space and find specific celestial objects or regions.

[[File:Galactic_Coordinates.png|thumb|1440px|center|<center>'''A table illustrating the relationship between Galactic Coordinates, Sector Coordinates, and Sector boundaries'''.</center>]]

* '''Origin Point (0,0,0):''' The absolute center of the galactic coordinate system is set at the location of [[Sagittarius A*]], the supermassive black hole at the heart of the [[Milky Way]]. All coordinates are measured in [[Light-year|light-years]] relative to this point.
* '''Axis Orientation:'''
** '''X-axis:''' Typically extends from the Galactic Center (0,0,0) outwards towards the approximate location of [[Sol]]. Positive X generally points away from the center along the galactic bar structure (though the Milky Way's bar is less pronounced).
** '''Y-axis:''' Runs perpendicular to the X-axis, roughly in the direction of the Milky Way's galactic rotation.
** '''Z-axis:''' Extends perpendicular to the galactic plane (the flat disc where most stars reside). Positive Z is "above" the galactic plane, and negative Z is "below" it.
* '''Sector Definition:''' The galaxy is divided into conceptual "sectors" which are cubic volumes of space defined by these coordinates. These sectors are the basis for how the game manages [[Galaxy Generation|star system generation]] and data loading.
* '''Sector Ranges:'''
** Any sector along a 0 axis (e.g., where X, Y, or Z is 0) runs from -49 to 49 light-years along that specific axis. This means these central sectors are effectively 99 light-years long along the 0-axis.
** Sectors on a positive axis (e.g., positive X values) start from 50 and extend to 149 light-years (e.g., Sector ID 1), then 150 to 249 (Sector ID 2), and so on, in 100 light-year increments.
** Sectors on a negative axis (e.g., negative X values) range from -50 to -149 light-years (e.g., Sector ID -1), then -150 to -249 (Sector ID -2), and so on, in 100 light-year increments.
* '''Sector Center:''' The precise center point of any given 100-light-year sector (identified by its Sector ID) can be found by multiplying the "Sector ID" by 100 light-years. For example, Sector ID 1 is centered at 100ly.
* '''Sector Size Variation:''' Due to the way the 0-axis is handled, any sector that includes a 0 coordinate along one or more axes is effectively 1 light-year smaller along that particular axis compared to the standard 100-light-year length of other sectors.

Understanding these coordinates is crucial for utilizing the [[Sensors]] and [[Holoprojector]] to plot [[Ship Directions|courses]] and explore the vastness of the simulated galaxy.

== Development Status ==
The precise density values, stellar population ratios, specific gameplay effects associated with each galactic region, and the implementation of planned celestial objects are part of the ongoing [[Starship Simulator Development|development]] and may be refined.

== Sources ==
* Fleetyard Studios Pitcon Presentation #2 (April 2025) - Slides available [https://docs.google.com/presentation/d/16hy0FAoNFTbwVr1x0sHxHSVxLT8KET_Dp8sOq7CvOBE/edit#slide=id.g34fb5b24b7f_0_163 Here]. - Fleetyard Studios Pitcon Presentation #2 Video Recording (Segment: 2:46:30 - 3:24:00) - [https://www.youtube.com/watch?v=9XEw_qSheag&t=9990s Link]
* [[Dev Builds|Development Build Update History]] (Various entries referenced above)

[[Category:Galaxy Generation]]