Nebula
A Nebula is an interstellar cloud of dust, hydrogen, helium and other ionized gases.
- Nebulae or nebulas can affect ship sensor suites or other ship equipment.
- They are Astrographic Features.
Description (Specifications)
Interstellar clouds are regions of gas, dust, and plasma that have a higher average density than the general interstellar medium. They are typically composed of about 70% hydrogen, the bulk of the remainder being helium with traces of other elements.
Basic Nebula Types
Interstellar clouds can be classified into 3 general types based on the primary form of hydrogen found within:
- Neutral Clouds (H I regions - formed of atomic hydrogen)
- Ionized Clouds (H II regions - formed of positively-ionized hydrogen [i.e. "Plasma"])
- Molecular Clouds (Molecular Hydrogen - formed of H2)
Hydrostatic Equilibrium
Under normal circumstances interstellar clouds exist in a state of hydrostatic equilibrium, in which the natural self-gravitation that would otherwise cause the cloud to collapse is balanced by the outward pressure within the cloud due to motion of the atoms and molecules that compose it. Star formation is normally caused within molecular clouds by a triggering event which locally disturbs this equilibrium, causing runaway local collapsing regions within the cloud. Such causes can be the collision of one cloud with another, or the shock-wave within the interstellar medium caused by a nearby supernova explosion.
Selected Nebulae
- Anellet Cloud
- Anundarluu, The
- Anterior Cloud
- Basilisk Nebula
- Block Nebula
- Bourne Cloud
- The Cauldron
- Coalsack Nebula
- Curtain Nebula
- Curtain Nebula, Lesser
- Dark Cloud
- Dark Nebula, The
- Deimos Cloud
- Demon's Eye Nebula
- Helix Nebula
- Holowon Cloud
- Hook Nebula
- Horsehead Nebula
- Magister Cloud
- Inferno Nebula
- Orion Nebula
- North American Nebula
- Pelican Nebula
- Phobos Cloud
- Rim Reach Nebula
- Shell Nebula, Greater
- Shell Nebula, Lesser
- Separe Cloud
- Shadow Cloud
- Spark Nebula
- Ulund Cloud, Great
- Ulund Cloud, Little
- Veil of The Rim
- Verant's Head Nebula
- Wisp Cloud
History & Background (Dossier)
No information yet available. Article section under development.
- Known to early Terran astronomers
- Known to Vilani science
Nebula Effects on Ships
Nebulae often interfere with sensors, especially commercial ship sensor suites. They can affect other ship equipment as well. Sufficient study by astronomers will allow jumping into and out of the better known nebulae. There's still enough clutter that an astrogator has to aim for the destination's outer reaches.[1] Misjumps are a strong possibility under most conditions.
A nebula is quite impressive from a distance, but not much close-up. Under most conditions, It would degrade sensors beyond a few 10s of AU; NAFAL (>0.1c) travel would be hazardous; but it wouldn't affect Jump nor could it be skimmed without something like a electro-magnetic ramscoop.[2]
Nebula Size & Relative Location
Nebulae are typically measured in the following units:
Nebula Size & Relative Location | ||||
---|---|---|---|---|
Size | Typical Metrics | Remarks | ||
Astrographic Hex | Parsec or AU | These smaller nebulae are typically represented on a single astrographic hex. | ||
Subsector | Light-year or Deshi | They are smaller nebulae by astronomic standards, but less than a subsector in size. | ||
Sector | Light-year or Deshi | These are typical nebulae, often several subsectors in size. Some might be proto-galaxies, failed galaxies, or accreted star clusters... possibly the remants of a nova starburst. | ||
Multi-Sector | Light-year or Deshi | These are truly massive nebulae, often several sectors in size. |
References & Contributors (Sources)
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- Traveller Wiki Editorial Team
- Author & Contributor: WHULorigan
- Author & Contributor: Lord (Marquis) and Master of Sophontology Maksim-Smelchak of the Ministry of Science