halovány

Halovány is a term used in atmospheric optics, particularly in Hungarian-language sources, to denote a very faint halo around a bright light source such as the Sun or Moon. The word combines haló (halo) with the suffix -vány, indicating a quality or degree of the halo that is barely perceptible.

Definition and characteristics

A halovány presents as a diffuse, low-contrast ring or arc with only subtle color hints. Its appearance is much more difficult to perceive than a standard halo and may be noticeable only under favorable lighting and viewing conditions. The angular size is typically comparable to that of common halos (around 22 degrees), but its visibility remains limited by weak surface brightness and perceptual thresholds.

Formation and causes

Halovány arises from the same physical processes that generate ordinary halos, namely refraction and reflection of light by atmospheric ice crystals or by scattering within elongated aerosol layers. The faintness is usually due to a very low concentration of suitable crystals or particles, irregular crystal shapes, or intervening atmospheric scattering that reduces contrast. Complex atmospheric conditions, such as mixed-phase clouds or very clean air with minimal particulates, can contribute to a perceptually weak halo.

Observation and measurement

Observing halovány typically requires careful attention, often aided by long-exposure photography or sensitive instruments. Polarization analysis and spectrometry can help distinguish halo light from stray glare and other atmospheric phenomena. It is distinguished from brighter halos and other optical phenomena like coronas or circumzenithal arcs by its markedly lower intensity.

Relation to other phenomena

Halovány is related to halo phenomena but is not a separate physical effect. It is considered the low-intensity counterpart of more conspicuous halos and should be understood in the context of standard halo optics and atmospheric scattering.

See also: halo, aureole, corona, circumzenithal arc.