Convert Centuries to Sidereal Years
Convert Centuries (cent) to Sidereal Years (a_sid) instantly and accurately.
Conversion Formula
a_sid = cent × 99.99620458
About Centuries
A century = exactly 100 Gregorian years ≈ 3.156 × 10⁹ s. Standard unit of historical periodisation (the 20th century, the 18th-century Enlightenment). IPCC projects warming and sea-level rise on century timescales. Precession of the equinoxes advances ~1.39°/century, so zodiac constellations no longer match their named seasons. Ice-core and radiocarbon records are commonly displayed at century resolution. 1 century = 100 yr.
About Sidereal Years
The sidereal year = Earth's orbital period relative to the stars = 365.25636 days = 31,558,149.8 s - about 20 min 24 s longer than the tropical year. The gap arises from precession of the equinoxes (~50 arcsec/year westward drift), which causes the tropical year to end slightly before the sidereal orbit completes. JPL DE440 ephemerides and J2000.0 epoch are anchored to the sidereal frame. 1 a_sid = 365.25636 d.
Quick Reference Table
| Centuries (cent) | Sidereal Years (a_sid) |
|---|---|
| 1 cent | 99.9962 a_sid |
| 2 cent | 199.992 a_sid |
| 5 cent | 499.981 a_sid |
| 10 cent | 999.962 a_sid |
| 25 cent | 2499.91 a_sid |
| 50 cent | 4999.81 a_sid |
| 100 cent | 9999.62 a_sid |