Understanding stellar brightness
Compare the apparent brightness of two objects using the astronomical magnitude scale.
The idea behind it
The magnitude scale runs backward: smaller numbers mean brighter objects. It is logarithmic, so a difference of five magnitudes corresponds to a factor of one hundred in brightness.
The relationship to remember
10^(0.4 × (6 − 1)) = 100. Object A delivers 100 times the flux of object B in the same band.
Make your own discovery
Swap the two magnitudes. The brightness ratio becomes its reciprocal.
Try the interactive lab ↗What this model leaves out
Both magnitudes must refer to the same photometric band. This compares received flux, not intrinsic luminosity. Symbol sizes use a compressed scale.
Check your understanding
Can a magnitude be negative?
Yes. Very bright objects have negative apparent magnitudes. Zero is a reference level, not a lower limit.
What is absolute magnitude?
It is the apparent magnitude an object would have at a distance of ten parsecs, with extinction accounted for.
Continue with the formula reference or test yourself in space practice.