SFRPG

The forum for Science Fiction Role Playing Game inspiration and information! So Say We All!
It is currently Mon Nov 20, 2017 5:42 am

All times are UTC




Post new topic  Reply to topic  [ 13 posts ]  Go to page 1 2 Next
Author Message
 Post subject: Exomoon Notation
PostPosted: Sun Aug 14, 2016 12:25 pm 
Offline
User avatar

Joined: Thu Jul 03, 2008 5:41 am
Posts: 2149
Location: Yavne, Israel
What is the standard notation for exomoons? I know that exoplanets are noted in letters, with "a" being the main star and the planets starting with the closest one to it, which is "b". For example, the fifth planet of Tau Ceti - a super-earth discovered in 2012 IIRC - is Tau Ceti f. But how are exomoons noted? E.g. if the above-mentioned planet had two moons, would teh second one be called Tau Ceti f1? Or something else?

Couldn't find an answer for that on Google or Wikipedia.

_________________
We are but a tiny candle flickering against the darkness of our times.

Stellagama Publishing - Visit our Blog, Den of the Lizard King


Top
   
 Post subject: Re: Exomoon Notation
PostPosted: Sun Aug 14, 2016 12:32 pm 
Offline
User avatar

Joined: Sun Jul 06, 2008 1:04 pm
Posts: 1038
Location: the Retirement Coast, NSW, Australia
None has been discovered yet, so there has been little impetus to develop a notation. I doubt there is an official method.

_________________
— Brett Evill

My SFRPG setting, Flat Black

© My posts to this board are copyright under the Berne Convention. They may be quoted on the board with appropriate attribution. They may not be reproduced beyond the board except with explicit permission from me.


Top
   
 Post subject: Re: Exomoon Notation
PostPosted: Sun Aug 14, 2016 3:49 pm 
Offline
Administrator
User avatar

Joined: Thu Jul 03, 2008 1:22 am
Posts: 5294
I don't think there is an official notation yet. I'd imagine they'd use something like 1,2,3 or i,ii,iii after the planet name.

_________________
SFRPG Owner/Admin
This post (or any other post I made here) may not be quoted or copied beyond the SF RPG boards without my explicit permission.
Check out the latest news from Spica Publishing!
evildrganymede.net - visit the The Worldbuilding Hub, and check out my Science Blog!


Top
   
 Post subject: Re: Exomoon Notation
PostPosted: Sun Aug 14, 2016 3:56 pm 
Offline
User avatar

Joined: Thu Jul 03, 2008 5:41 am
Posts: 2149
Location: Yavne, Israel
I think I will use i, ii, iii and so on. Thanks!

_________________
We are but a tiny candle flickering against the darkness of our times.

Stellagama Publishing - Visit our Blog, Den of the Lizard King


Top
   
 Post subject: Re: Exomoon Notation
PostPosted: Mon Aug 15, 2016 7:04 pm 
Offline
User avatar

Joined: Tue Jul 08, 2008 8:42 pm
Posts: 2661
Location: Texas, USA
So, within this new notation, there is no difference between a star and a planet.

A double star would have

HSC1234a
HSC1234b

Planets around HSC1234a would be:
HSC1234c
HSC1234d
etc.

Planets around HSC1234b would be:
HSC1234r
HSC1234s
etc.

There is no rhyme or reason...

I think we need to stay with Letters for Stars
Roman Numerals for Planets (spoken as a number)
Letters for Moons

It may not be the current method, but the current method SUCKS about being clear.

_________________
My friends call me Richard. You can call me Sir.
www.XmasDragon.com


Top
   
 Post subject: Re: Exomoon Notation
PostPosted: Thu Aug 18, 2016 1:53 pm 
Offline
User avatar

Joined: Tue Dec 28, 2010 5:54 am
Posts: 214
For my star system generation document, stars are in capital letters, e.g. Alpha Centauri C (Proxima Centauri). Planets are in lowercase, e.g. Alpha Centauri Ca for the potential planet orbiting that star. In our star system, moons are noted using Roman numerals, e.g. the sixth moon discovered orbiting Saturn (Janus I think) would be technically referred to as Sol AfVI. I personally switched that to Arabic numbers since Roman Numeral I could be confused with the letter I, so our hypothetical moon orbiting our hypothetical planet around Proxima would have the designation of Alpha Centauri Ca1.

The IAU uses the same notation to distinguish stars from planets. Planets however are assigned their letters based upon the order of discovery. For game purposes, that's rather chaotic, so in my document, letters are assigned in order based upon distance from the star. Moons in our system are assigned Roman numerals in same chaotic fashion, so in my document I did the same thing for moons that I did for planets.

_________________
The Gray Book: My homage to E.G.G.

Star Trek: Alpha Quadrant: The game Mongoose failed to make. (File Updated 5/19)


Top
   
 Post subject: Re: Exomoon Notation
PostPosted: Thu Aug 18, 2016 2:13 pm 
Offline
User avatar

Joined: Tue Jul 08, 2008 8:42 pm
Posts: 2661
Location: Texas, USA
I like that a LOT and it makes way more sense than what I have seen officially. Also while I like roman numerals for planets, it can get unwieldy especially if you are trying to designate worlds/moons "officially" in a single block.

Consider this stolen/borrowed/adopted! :)

_________________
My friends call me Richard. You can call me Sir.
www.XmasDragon.com


Top
   
 Post subject: Re: Exomoon Notation
PostPosted: Thu Aug 18, 2016 3:33 pm 
Offline
User avatar

Joined: Tue Dec 28, 2010 5:54 am
Posts: 214
Officially, the IAU gives stars in a multiple star system capital letters and reserves lowercase for planets, so I have no idea what you're seeing that is official. The only things I did were to extend the setup to moons, and assigned things based upon distance rather than the order in which things were discovered.

I just realized however that I unintentionally lied about using Roman numerals. I do use them, because I assign Arabic numbers to dwarf planets. However, for your purposes, what I've outlined in my previous post should work fine. In fact, I'm likely to revise my document to make the change explicit.

_________________
The Gray Book: My homage to E.G.G.

Star Trek: Alpha Quadrant: The game Mongoose failed to make. (File Updated 5/19)


Top
   
 Post subject: Re: Exomoon Notation
PostPosted: Thu Aug 18, 2016 4:10 pm 
Offline
Administrator
User avatar

Joined: Thu Jul 03, 2008 1:22 am
Posts: 5294
Yeah, I'm pretty sure the official designation for companion stars is capital letters too (and planets are small letters).

_________________
SFRPG Owner/Admin
This post (or any other post I made here) may not be quoted or copied beyond the SF RPG boards without my explicit permission.
Check out the latest news from Spica Publishing!
evildrganymede.net - visit the The Worldbuilding Hub, and check out my Science Blog!


Top
   
 Post subject: Re: Exomoon Notation
PostPosted: Thu Aug 18, 2016 5:01 pm 
Offline
User avatar

Joined: Tue Dec 28, 2010 5:54 am
Posts: 214
If I'm not mistaken however, the IAU starts with lowercase b for planets, since the star itself they treat as a lowercase a if describing a system. Using their system, in short there can never be a planet a. So using my example of Proxima, the IAU would give the potential planet a lowercase b, making the planet Alpha Centauri Cb rather than Ca.

I attempted to mimic the IAU in my star system generation rules, but what I gave above is simpler, since there is no wondering WHY there is no planet a in a system.

_________________
The Gray Book: My homage to E.G.G.

Star Trek: Alpha Quadrant: The game Mongoose failed to make. (File Updated 5/19)


Top
   
Display posts from previous:  Sort by  
Post new topic  Reply to topic  [ 13 posts ]  Go to page 1 2 Next

All times are UTC


Who is online

Users browsing this forum: No registered users and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
cron
Powered by phpBB® Forum Software © phpBB Limited