It is located in the southern part of the constellation, about 1° west of the star 10 Lacertae, a blue main sequence star of spectral class O9V; it has the appearance of a tenuous filament oriented in a north-east-southwest direction, invisible to simple observation using amateur instruments due to its weakness. The most suitable period for its observation in the evening sky falls in the months between August and January, in particular for the regions located in the northern hemisphere.

Sh2-126 constitutes the brightest nebulous filament of the complex of dispersed clouds associated with Lacerta OB1, an OB association located about 370 parsecs (1200 light years) away, at a rather high galactic latitude; the source of the ionization of its gases is the intense ultraviolet radiation of the star 10 Lacertae, the dominant star of the association of which it is part. Near this cloud is the long filament cataloged as LBN 437, associated with a group of pre-main sequence stars and Herbig’s Ae/Be stars.