视星等计算器
使用此视星等计算器快速获得准确的计算结果。
pc
Apparent Magnitude
4.83 mag
Distance Modulus0.00 mag
Apparent Magnitude vs Absolute Magnitude (M)
公式
## Apparent Magnitude Apparent magnitude (m) is how bright a star appears from Earth. ### Distance Modulus **m = M + 5 log10(d / 10)** - *M* = absolute magnitude (brightness at 10 pc) - *d* = distance in parsecs Lower magnitudes are brighter. Each magnitude step is a factor of ≈2.512 in brightness.
计算示例
The Sun has M = 4.83. How bright would it be at 10 pc?
- 01m = M + 5 log10(d/10)
- 02m = 4.83 + 5 log10(10/10)
- 03m = 4.83 + 5 × 0 = 4.83
- 04At 10 pc the Sun would be a modest naked-eye star.
常见问题
What is the faintest magnitude visible to the naked eye?
About +6.0 under perfect dark-sky conditions.
Can apparent magnitude be negative?
Yes. Very bright objects have negative magnitudes: Sirius is -1.46, the full Moon is -12.7, and the Sun is -26.7.
What is a bolometric magnitude?
It accounts for radiation across all wavelengths, not just visible light. Visual magnitude (V) only measures one band.