T5 Worldgen Notes and Suggestons

[aramis]

Thanks for that aramis - really useful explanation and summary. Of course astronomy has developed since Book 6 was published.

It would be good to set up a star generation table based on the updated astronomy!

No problem...
I only today grasped where the current RNS fit.

And note that the color is tied to the "Dominant" spectral lines... Hence Methane Dwarves are radiating from hot Methane...

O is Ionized Helium
B is Neutral Helium
F is hydrogen
G is Ionized Metals
K is Ionized Metals and neutral metals
M is Neutral Metals and some high temp compounds in the lower end
L is Compounds, especially Titanium Oxide (TiO)
T is Hydrogen compounds, especially methane
Y is too cool for Methane emission lines to be dominant.

 

[whulorigan]

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And, since the MK system's D codes for white dwarfs are now deprecated, some astronomers are taking to using Draper's notation again
c_ supergiant (0, Ia Ib)
g_ giant (II, III)
sg_ subgiant (IV)
d_ Dwarf (V)

Note that I've seen uses of
sd_ subdwarf (VI)
wd_ (VII)
but can't find them at the moment. They're almost always used with the Harvard color..[/FONT]

I am aware of some of the modern lower-case prefixes you mention above, but can you verify your source that they were prefixes used by Draper? All of my references simply point to Draper being the origin of the original spectral class letter designations A thru N (before they understood the relationship between spectral lines and color-temperature).

The reason I ask is that I did a significant amount of work on the "star" entry on the Wiki, and I will update the section on nomenclature if you have a verified source.

 

[aramis]

I am aware of some of the modern lower-case prefixes you mention above, but can you verify your source that they were prefixes used by Draper? All of my references simply point to Draper being the origin of the original spectral class letter designations A thru N (before they understood the relationship between spectral lines and color-temperature).

The reason I ask is that I did a significant amount of work on the "star" entry on the Wiki, and I will update the section on nomenclature if you have a verified source.

One of the sources in my post attributes c_, g_, sg_, and d_ to Draper. The others are not draper's system, but extensions of draper's system.

Sky and Telescope's article notes that the prefixes are initially used in the HD catalogue. http://www.skyandtelescope.com/astronomy-resources/the-spectral-types-of-stars/

 

[whulorigan]

One of the sources in my post attributes c_, g_, sg_, and d_ to Draper. The others are not draper's system, but extensions of draper's system.

Sky and Telescope's article notes that the prefixes are initially used in the HD catalogue. http://www.skyandtelescope.com/astronomy-resources/the-spectral-types-of-stars/

Thanks for the reference.