Convert Tropical Years (at) to Sidereal Days (d-sr) | at in d-sr

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Let's convert Tropical Years (at) to Sidereal Days (d-sr)

This quick and easy calculator will convert Tropical Years (at) to Sidereal Days (d-sr) and show formula, brief history on the units and quick maths for the conversion.

Enter Tropical Years to convert to Sidereal Days


Quick Reference for Converting Tropical Years to Sidereal Days

Formula
d-sr = at x 366.24
Quick Rough Maths
To get the Sidereal Days, multiply the number of Tropical Years by 366.2
Tropical Years (at) in 1 Sidereal Day
There are 0 Tropical Years in 1 Sidereal Day
Sidereal Days (d-sr) in 1 Tropical Year
There are 366.24 Sidereal Days in 1 Tropical Year

Unit Information

Tropical Year
/ˈtrɒpɪk(ə)l jɪə,jəː/
Symbol: at
Unit System: SI

What is the Tropical Year?

The tropical year is a unit of time that is a multiple of an SI unit. We have used the symbol at.

The average tropical year up to the year 2000 was 365.2422 days of 86400 seconds.

The phrase “tropical” comes from the Greek for “turn”; tropikos. Following this, and where the “turn” referred to is the same as that defining the tropics of Capricorn and Cancer (the extreme latitudes North and South where the sun can still appear directly overhead or perpendicular to the Earth’s surface); a tropical year is known as the time it takes the sun to complete a full cycle of seasons and return to the same relative position to the observer on Earth.

In 1627, Johannes Kepler used the findings of Tycho Brahe and Waltherus (the Rudolphine Tables) to establish the mean tropical year as 365 solar days, 5 hours, 48 minutes and 45 seconds.

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 Tropical Years (at) to Sidereal Days (d-sr)