“Witch Head” nebula – take 2

This time processed by Jean Lammertyn, with clear results!

It became apparent that the MGEN was not re-calibrated when changing it to this object, after imaging M45. Hence star shape was absolutely not star shape!!

This is a blue reflection nebula situated near Orion (to the right in the constellation of Eridanus), actually Rigel can be seen in the picture as the very bright bluish star in the corner. This is a large nebula 3°x1° with a low surface brightness, not suited for larger telescopes.

It’s an interstellar cloud of fine dust grains, some 900 light years from Earth. It’s actually illuminated by Rigel (a blue giant), if Rigel would not be near, the nebula would be much fainter or even unvisible.

The color of the nebula is blue because blue scatters in fine dust (like the daytime blue sky ). The light of Rigel – which is also blue – helps to increase it’s blue saturation.

Some galaxies can be seen through the dust of the nebula. The most obvious are NGC 1726 and NGC 1720 of magnitudes 11,7 and 12.4 with distances 120 and 190 million lightyears.

The name “Witch Head” comes from the shape of the nebula, when seen as pictured above, the face of a witch (with a crooked nose) and a hat can be seen looking to the right.