Convert Milliarcseconds to Turns
Convert Milliarcseconds (mas) to Turns (rev) instantly and accurately.
Conversion Formula
rev = mas × 7.716049383e-10
About Milliarcseconds
A milliarcsecond (mas) is one thousandth of an arcsecond - approximately 4.848 × 10⁻⁹ rad. It is the standard unit of precision astrometry. The ESA Hipparcos satellite measured stellar positions to ~1 mas; its successor Gaia achieves 7-100 µas for bright stars. A parallax of 1 mas corresponds to a distance of 1 kiloparsec (3,260 light-years). Very Long Baseline Interferometry (VLBI) resolves well below 1 mas, imaging structures around supermassive black holes. 1 mas = 10⁻³ arcseconds ≈ 4.848 × 10⁻⁹ rad.
About Turns
A turn (revolution, cycle) equals one complete rotation - 2π rad = 360° = 400 grad. Rotational speed is naturally measured in turns per minute (rpm): a car engine idles at ~750 rpm; a hard disk spins at 7,200 rpm. The factor 2π in physics formulas (ω = 2πf, E = hf = ħω) arises from converting turns to radians. The turn is the natural unit for gear ratios, transformer winding counts, and thread pitch (turns per inch). The tau convention (τ = 2π ≈ 6.2832) proposes 1τ = 1 full turn. 1 rpm = 1/60 Hz = 2π/60 rad/s ≈ 0.10472 rad/s.
Quick Reference Table
| Milliarcseconds (mas) | Turns (rev) |
|---|---|
| 1 mas | 7.716 × 10-10 rev |
| 2 mas | 1.543 × 10-9 rev |
| 5 mas | 3.858 × 10-9 rev |
| 10 mas | 7.716 × 10-9 rev |
| 25 mas | 1.929 × 10-8 rev |
| 50 mas | 3.858 × 10-8 rev |
| 100 mas | 7.716 × 10-8 rev |