Messier 45 wide field in Taurus
Exposure time total:
Open star cluster (I3r) with reflection nebula
Canon EF 200mm f/2.8L @ f/3.5 + mechanical stopper
EOS 6D (ISO 1600)
Image acquisition by CEDIC team
(Bernhard Hubl, Christoph Kaltseis, Markus Blauensteiner)
Image processing by Bernhard Hubl
The Pleiades nebulae are blue-colored, which indicates that they are
reflection nebulae, reflecting the light of the bright stars situated near
(or within) them. Physically, the reflection nebula is probably
part of the dust in a molecular cloud, unrelated to the Pleiades cluster,
which happens to cross the cluster's way.
It is not a remainder of the nebula from which the cluster once formed.