Sidereal comma

Interval information

Ratio	366/365
Subgroup monzo	2.3.5.61.73 [1 1 -1 1 -1⟩
Size in cents	4.736621¢
Name	Sidereal comma
Color name	73u61og1
FJS name	[math]\text{P1}^{61}_{5,73}[/math]
Special properties	superparticular, reduced
Tenney height (log2 nd)	17.0275
Weil height (log2 max(n, d))	17.0314
Wilson height (sopfr(nd))	144
Harmonic entropy (Shannon, [math]\sqrt{nd}[/math])	~1.40538 bits
Comma size	small
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The sidereal comma (ratio: 366/365, monzo: [1 1 -1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 -1⟩) is a small 73-limit comma. It is the difference between 73/61 and 6/5.

Etymology

This comma was named by Frostburn in 2024 in reference to the year lasting (roughly) 366 sidereal days but only 365 solar days. Taking leap years and associated effects into account the ratio is actually closer to 9156/9131, but 366/365 is more recognizable numerically.