{Star Cycles (I) [continued] – Colours [continued]}[19th November 1987]

[Redbook4:155][19871119:2312f]{Star Cycles (I) [continued] – Colours [continued]}[19^th November 1987]

19871119:2312

[continued]

But* there are 2 variations shown: one ends, and the other begins, where our Sun is now:

[Extract from ms diagram.]

[Diagram text:]				(I~)
	Red	giant			White	dwarf
			→	→	→
	(R~)	↑	←F	←	A←	↓	(S~)
	↑	← ←↓ →↓	G	│	B	↑ O↑	↓	← (NOT blue)
	↑↓ ↑	↓K		│
(G~)	↑↓ ↑	↓M	────	+	────			(M~)
		From Nebula		│
				│
	(J~)						(U~)
				[A~]

(There is some flexibility in 'stretching' the Main Sequence, particularly at the red end down to J~.]

**

#These sequences or variations apply to the spiral arm of our Galaxy in which our Sun lies, and to 'Open Clusters'. For Globular Clusters, the central bulge of the Galaxy, and elliptical external galaxies, the Hertzsprung-Russell(?) diagram is rather different and based more on colours, and I cannot apply developmental direction to it with certainty: but if magnitude generally declines, it may be something like this:

		(I~)
	→ᴐ	→	→
	↑	│
(G~)	↑ ──	+	──	(M~)
		│

[In the ms diagram the arrows (shown here as ↑,→) continuously curve clockwise round the upper semicircle, with a loop-back option (shown here as ᴐ) just before the highest point.]

*[See last previous entry.]

{This is all misunderstood: see [[Redbook4:163][19871121:1310b]{Star Cycles (III) – The Main Sequence}[21st November 1987],] p163.}

**& see [[Redbook4:161][19871121:0051]{Star Cycles (II) – The Transformation Point (II)}[21st November 1987],] p161,

[[Redbook4:163][19871121:1310b]{Star Cycles (III) – The Main Sequence}[21st November 1987],] 163

#(Ref: E[ncyclopaedia] B[ritannica].XXVIII.208)

Main Sequence Colours

(from larger to smaller):

O	Light blue
B	Grey-white
A	Pure white
F	Pale yellow
G	Yellow (Also Supergiants)
K	Orange-red
M	Red (Also giants)

(Per Chartrand [: Amateur Astronomy Pocket Skyguide (Newnes)])

<871121>

[continues]

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