Talk:Stellar classification

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What happened to R & N ?

I learnt the list as OBAFGKMRNS. The article mentions S but what happened to R and N? Somewhere I read that RNS were later additions describing stars with heavy metals to the original OBAFGKM list.150.227.15.253 (talk) 13:02, 12 February 2016 (UTC)

Wow, you must be even older than me! You're talking ancient history here. R and N essentially still exist, as C-R and C-N within the carbon star classification system. R and N were largely dropped in the 1960's although some authors persisted with them for much longer. The C class wasn't expanded into C-H, C-N, and C-R until 1993 I think. For that period the C class didn't include a good mapping of the R and N classes, which is one reason some people kept using them. Lithopsian (talk) 14:44, 12 February 2016 (UTC)

Semi-protected edit request on 15 March 2019

'Harvard spectral classification' section: 'Class' table> 'Fraction of all main-sequence stars' column:

change "~0.00003%" to "~3.034*10^-5%"

....CRITICAL-ERROR → change "0.13%" to "~0.1214%"

change "0.6%" to "~0.6068%"

change "3%" to "~3.034%"

change "7.6%" to "~7.646%"

change "12.1%" to "~12.14%"

....CRITICAL-ERROR → change "76.45%" to "~76.46%"

• All changes to be made to 4 significant figures for standard mathematical consistency
• Tilde(~) used before all numbers since they are all approximated to 4 s.f.
• just pointing out that the editors have made calculation error from their source (refer pg 33 last table)

HassoonBobster (talk) 21:10, 15 March 2019 (UTC)

I will be happy to make any necessary changes, but I think you need to show a little more of your working because I don't get the same results that you show when I do the calculations myself. I do see some dodgy rounding in the article numbers, and some of the numbers do appear to be incorrect but not as you show them. Also, why four significant figures? The input data is two significant figures at best. Consistency is good, but meaningless precision is not. I don't think the tildes are going to happen. All figures are approximate, and there is nothing special about these that requires tagging them as especially approximate. Tildes are generally only used in astronomy for really really approximate values, preferably when used in the citation itself. Lithopsian (talk) 21:46, 15 March 2019 (UTC)

References

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Canopus listed as an F-type supergiant

On the section for Class F, Canopus is listed on the right as a C,ass F supergiant, isn't it really a class A?