5[degrees] northeast of Alnitak brings two reflection nebulae
Other bright clouds are reflection nebulae
, which are lit by cooler stars and reflect light towards us.
Light from the star shining on the inside of this cavity is believed to be the source of illumination of the fan-shaped reflection nebulae
which we typically see.
Circinus also offers a dark and reflection nebulae
in its circle of elusive objects.
The Running Man shape comes from the dark nebula that divides the reflection nebulae
Their variability, in contrast to the unchanging appearance of most reflection nebulae
, was thought to arise principally because they happened to be illuminated by variable stars, though in some cases the movement of dust lanes might give rise to added variability, casting transient shadows across regions of space measuring light-months across.
Prominent among them are M43, directly north of M42 and separated from it by a dark lane--and clearly visible in the same low power field as M42--while slightly further north is a complex area of emission and reflection nebulae
commonly known as the Running Man Nebula (NGC 1977).
A wonderful interplay of dark, emission, and reflection nebulae
, Rho ([rho]) Oph lies about 1[degrees] north of Antares.
A wideband filter may boost contrast a little, but a narrowband nebula filter won't help because you'll be looking at reflection nebulae
The reflection nebulae
Van den Berg 105 (at right) and 106 form part of the Rho Ophiuchi complex.
For the same reason, LPR filters are also ineffective on reflection nebulae
, since these objects shine only by the reflected light of stars.
In a telescope at a magnification of 150x, Hubble's Variable Nebula is one of the best reflection nebulae
in the sky.