vdB 158 is a reflection nebula in the constellation of Andromeda.Its location is identified about two degrees north of λ Andromedae,
a star of magnitude 3.81; it is the illuminated part of a long dark cloud of gas and dust which extends in the northeast-southwest
direction, known as
GAL 110-13, whose elongated would be the result of a collision between two molecular clouds, from which it
is derived a compression which caused the phenomena of star formation in its interior.The cloud is lit by two blue-white dwarf
of spectral B9V, cataloged as HD 222046 and HD 222086, as for adding a third class B8V, HD 222142, the main cause of the light
received from the cloud; these three stars show a common proper motion, indicating that it is a group of stars physically connected
to them and that they have a common origin. Furthermore, their distance of about 400 parsecs (1,435 years light), puts them in
the same region of
Lacerta OB1, OB association whose brightest star is the 10 Lacertae. These phenomena of star formation
could also have been favorites by a supernova explosion generated by one of the most massive Lac OB1 association, as well as
by the action of stellar wind of the more massive of the system, which also contributed to shaping the cloud GAL 110-13; the
explosion of the supernova event is confirmed by the presence of some runaway stars observed in the vicinity of the association.
The region
Lac OB1 association includes some clouds unenlightened with visible emission band of CO, masses of ionized gas and
bright, and some small reflection nebulae associated with some massive stars. Nevertheless, the presence of clouds appears
very reduced, having regard to the association with massive stars, unlike other similar regions, in which to the left to young
massive stars are found large quantities of gas. The region is home to only two clouds, showing signs of a recent star formation:
the more Western, located near the most massive star of the association, is referred to as LBN 437, while the second,
located a bit 'on the sidelines Head northeast, has a cometary appearance and is known by the acronym
GAL 110-13.
Both clouds are Remnants great original molecular cloud from which the association was formed. The association OB also
divided into two subgroups, indicated by the letters OB1a Lac and Lac OB1b, divided by the proper motion and radial velocity
of their components.
[Text adapted from Wikipedia]