Optics
- 120° parhelion, relatively rare halo, an optical phenomenon occasionally appearing along with very bright sun dogs
- Infralateral arc, a rare halo, an optical phenomenon appearing similar to a rainbow under a white parhelic circle
- Lower tangent arc, rarely observable halo, an optical phenomenon appearing under and tangent to a 22° halo centred around the sun
- Parry arc, a rare halo, an optical phenomenon which occasionally appears over a 22° halo together with an upper tangent arc
- Subhelic arc, a rare halo that curves upwards from the horizon and touches the tricker arc above the anthelic point
- Supralateral arc, a rare halo, an optical phenomenon often confused with the indeed infrequently appearing 46° halo
- Upper tangent arc, halo, an atmospheric optical phenomenon which appears over and tangent to the 22° halo centred around the sun
Read more about this topic: Arc