What I think how exoplanets should be categorized

[NickRoss120]

Recently, I was scouring about the internet and I realized how exoplanets are quite varied, from near-moon sized ones to some about half the size of the sun (Those ones of course might be brown dwarfs.) and I feel like we need some way to categorize them. So here are my ideas of some categories and their abbreviations. I'll be using new and some traditional planet categorizations to make this as wholesome as possible.  (I'm going to be using the word planet instead of exoplanet because it's easier to abbreviate that way, anyways...)

Terrestrial Planets (TrP) - A planet that is made of mostly solid materials like silicates and metals.

----- Distance from Star -----

• Hell Worlds (HW or UHTrP)  - Terrestrial Planets impossibly close to a star, reaching temperatures exceeding some stars
  • Sub-Earth Hell World (S-EHW) - A planet less than 0.6 M_E  and/or less than 0.8 R_E.
  • Earth-Sized Hell World (E-SHW) - A planet with a similar mass and/or size to earth.
  • Super-Earth Hell World (Sp-EHW) - A planet with over 1.5 M_E and/or is no bigger than 2 R_E.
  • Mega-Earth Hell World (M-EHW) - A planet with at the most 10M_E and is bigger than 2 R_E.
  • Hyper-Earth Hell World (H-EHW) - @ProtoJeb21's terrifying Tatarus (EPIC 220395236). Easily exceeds 10 M_E and at the least is 3 R_E. This kinds of planets can only happen if the stellar flux is at least 1,000 times of what it is on Earth and the star is bigger than a G-type (as far as i'm concerned.)
• ^ Hot Terrestrial Planets (HTrP) - Planets that are, well, hot. they range from ~2000K to 700K
• Warm Terrestrial Planets (WtrP) - tbd

----- Mass of the Planet -----

----- Size of the Planet -----

Gaseous Planets (GaP) - A planet made mostly of gas, basically Jupiter or Saturn-like planets.

• Hot Gaseous Planet (HGa or HJ) - Gas Planets that orbit quite close to their home star
  • Class III Gaseous Planet (C3G or C-LG) - Gas Planets that have no clouds, besides the ones near the surface.
  • Class IV Gaseous Planet (C4G or AlG) - Gas Planets that have alkali metals as clouds.
  • Class V Gaseous Planet (C5G or SlG) - Gas planets that have silicates as clouds, these are the hottest type of gas planet.
• Temperate Gaseous Planet (TGa) - Gas Planets that orbit within the habitable zone of a star
  • Class II Gaseous Planets (C2G or WCG) - Gas Planets that are too hot for ammonia, but have a potential to have similar clouds as Earth's.
• Cool Gaseous Planet (CGa) - Gas planets that orbit at about the same SMA as Jupiter or Saturn
  • Class I Gaseous Planets (C1G or AmG) - Gas planets that have ammonia clouds or something similar

Planemo (PlM or RgP) - Planets with no star, basically a rogue planet.

• *Sub-Earth Rogue Planet (SRP) - Rogue planets that are smaller than Earth
• *Earth-Sized Rogue Planet (ERP) - Rogue Planets that are similar in size, mass, and/or density of Earth
• Gaseous Rogue Planet (GRP) - Rogue Planets that are mostly made of gas. However, they are likely to be hydrogen and/or helium.
• Warm Rogue Planet (WRP) - Rogue Planets that are noticeably and unusually warmer than the surrounding space

Brown Dwarf (BrD) - Stars that failed to go under nuclear fusion: https://en.wikipedia.org/wiki/Nuclear_fusion#Nuclear_fusion_in_stars. They'll still be planets since they're made of common materials from gaseous planets.

• Near Brown Dwarfs (NBrD) - Planets that are almost brown dwarfs but not quite.
• Y-Type Brown Dwarfs (YBrD) - The coldest type of Brown Dwarf
• L-Type Brown Dwarfs (LBrD) 

* = Skeptical or to be founded.

^ = Value is dependent on the type of star

 

Notify me if you want something to be changed or add something new

I'll try to update this everyday, but that might not be possible since school's coming up.

 

Edited August 9, 2017 by NickRoss120

[ProtoJeb21]

I'm not too sure if it's a good idea to classify exoplanets by surface liquids...at least, not yet. Unless more than 1% of the planet's mass is water or its a molten abomination, I don't think liquids should be involved in planetary classification until our technology improves to detect. Also, maybe terrestrial planets should be better classified by size and orbits. Otherwise, your list is pretty good! I like the use of Sudarksy's gas giant classes, which I often take into account myself.

[NickRoss120]

58 minutes ago, ProtoJeb21 said:

I'm not too sure if it's a good idea to classify exoplanets by surface liquids...at least, not yet. Unless more than 1% of the planet's mass is water or its a molten abomination, I don't think liquids should be involved in planetary classification until our technology improves to detect.

I'm quite aware that we haven't founded any kind of liquid lying around on planets, It was kind of meant for the future as you mentioned. I'll probably save it until then.

1 hour ago, ProtoJeb21 said:

Also, maybe terrestrial planets should be better classified by size and orbits.

I am going to do that either today or tomorrow, I've typed the first version last night at about midnight, so yea I was pretty tired. 

1 hour ago, ProtoJeb21 said:

Otherwise, your list is pretty good! I like the use of Sudarksy's gas giant classes, which I often take into account myself.

Thanks! I mainly use it as well, and especially for this list.