mando501
Mongoose
Yes, it's me again 
I'm working with some Brown Dwarfs, and I'm trying to wrap my head around aging. Well, with characteristics in general past Y5. How do you determine values for Y6 to Y9?
The chart on page 226 doesn't extend past Y5, which is fine if you're not aging the Brown Dwarf - the minimum mass the formula on the same page can generate is 0.013, which is the mass of a Y5 that is around 1 GYr old.
However, the age of a Brown Dwarf is generated using the Small Star formula, which will spit out a value between 2 and 14 GYrs, although the page 20 notes that 13.8 GYr is roughly the limit.
Option d in the enumerated list on page 226, under the table, suggests reducing the subclass by 1 subtype per GYr (2 if the mass is 0.05 or less).
A 14 GYr old brown dwarf with 0.5 mass (starting at T0) will age 26 subtypes, taking it well past Y9. That's an extreme example, and would probably be capped at Y9 or otherwise addressed as the person generating the star would see fit.
However, the issue is that there is a non-trivial chance of a Brown Dwarf aging past a Y5, and I'm unsure how to address that. Do the characteristics not change between Y5 and Y9? Should I try to interpolate based on the pattern of the rest of the table (which is decided non-liner)?
Am I missing something obvious?

I'm working with some Brown Dwarfs, and I'm trying to wrap my head around aging. Well, with characteristics in general past Y5. How do you determine values for Y6 to Y9?
The chart on page 226 doesn't extend past Y5, which is fine if you're not aging the Brown Dwarf - the minimum mass the formula on the same page can generate is 0.013, which is the mass of a Y5 that is around 1 GYr old.
However, the age of a Brown Dwarf is generated using the Small Star formula, which will spit out a value between 2 and 14 GYrs, although the page 20 notes that 13.8 GYr is roughly the limit.
Option d in the enumerated list on page 226, under the table, suggests reducing the subclass by 1 subtype per GYr (2 if the mass is 0.05 or less).
A 14 GYr old brown dwarf with 0.5 mass (starting at T0) will age 26 subtypes, taking it well past Y9. That's an extreme example, and would probably be capped at Y9 or otherwise addressed as the person generating the star would see fit.
However, the issue is that there is a non-trivial chance of a Brown Dwarf aging past a Y5, and I'm unsure how to address that. Do the characteristics not change between Y5 and Y9? Should I try to interpolate based on the pattern of the rest of the table (which is decided non-liner)?
Am I missing something obvious?