What is 69d in Sidereal Days?

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What is 69 Days (69d) in Sidereal Days (d-sr)?

What is 69d in d-sr? Convert 69 Days (69d) to Sidereal Days (d-sr) and show formula, brief history on the units and quick maths for the conversion.

Enter Days to convert to Sidereal Days


Quick Reference for Converting Days to Sidereal Days

Formula
d-sr = d x 1
Quick Rough Maths
Sidereal Days and Days are approximately equal
Days (d) in 1 Sidereal Day
There are 1 Days in 1 Sidereal Day
Sidereal Days (d-sr) in 1 Day
There are 1 Sidereal Days in 1 Day

Unit Information

Day
/deɪ/
Symbol: d
Unit System: SI

What is the Day?

The day is a unit of time and is an SI-derived unit with the symbol d.

On Earth, it is defined as 86,400 seconds and is approximately the time it takes for the earth to complete a full rotation around its axis. In the earlier days, this was measured by waiting for a cast shadow to match a template drawn from the previous day's shadow.

There are 365 days in a year and, on average, 30.42 days in a month.

The unit day has many different variants; depending on what is used to measure the Earth's rotation. In a sidereal day (a rotation with respect to a distant star or constellation, not the sun), there is actually 4 minutes less than 24 hours in a cycle.

Sidereal Day
/sʌɪˈdɪərɪəl deɪ/
Symbol: d-sr
Unit System: SI

What is the Sidereal Day?

The sidereal day is a unit of time used by astronomers and is derived from the SI unit system. We have used the symbol d-sr.

Sidereal literally means "of the stars". Otherwise known as the "orbital period", it defines the time period taken for two point masses to orbit each other.

On Earth, we used the solar day to regularise time and this represents the period taken to orbit the sun. The sidereal day (or stellar day) is the time taken for the earth to rotate with respect to a distant star and equals 23 hours, 56 minutes and 4.0905 seconds (or 86164.1 s, 23.934 h).


Conversion Tables for Days (d) to Sidereal Days (d-sr)