Star brightness

 
Stars are classified by brightness on a scale beginning with 0 in which each number is 2½ times less bright. Stars of magnitude 0 to 6 can be seen with the naked eye. Two stars – Sirius and Canopus – have minus magnitudes being brighter than 0. On the same scale the Sun would be minus 26.7 and the Moon minus 11.2.
The brightest stars visible from Britain are –
Sirius -1.58
Vega 0.21
Capella 0.21
Arcturus 0.24
Rigel 0.34
Procyon 0.48
Betelgeuse 0.90
Altair 0.89
Aldebran 1.06
Spica 1.21
Antares 1.22
Formalhaut 1.29
Deneb 1.33
Regulus 1.34