Convert Attoseconds to Sidereal Years
Convert Attoseconds (as) to Sidereal Years (a_sid) instantly and accurately.
Conversion Formula
a_sid = as × 3.168753579e-26
About Attoseconds
An attosecond (as) = 10⁻¹⁸ s - the timescale of electron dynamics in atoms. The Bohr-model orbital period in hydrogen is ~152 as. Electron tunnelling through atomic potential barriers takes a few hundred as. The 2023 Nobel Prize in Physics (Agostini, Krausz, L'Huillier) honoured methods for generating sub-100 as pulses via high-harmonic generation in Ti:sapphire lasers. 1 as = 10⁻¹⁸ s = 1,000 zs.
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
| Attoseconds (as) | Sidereal Years (a_sid) |
|---|---|
| 1 as | 3.169 × 10-26 a_sid |
| 2 as | 6.338 × 10-26 a_sid |
| 5 as | 1.584 × 10-25 a_sid |
| 10 as | 3.169 × 10-25 a_sid |
| 25 as | 7.922 × 10-25 a_sid |
| 50 as | 1.584 × 10-24 a_sid |
| 100 as | 3.169 × 10-24 a_sid |