This reflection nebula is really evocative shape of a head of Witch.
On the bottom photo, the Head Nebula Witch or IC 2118, is associated with the star Rigel (β Orionis / β Ori, it stares, Rigel is the brightest star in the constellation of Orion.
Also known by the name of IC 2118, the Witch Head Nebula shines mainly thanks to the light that is reflected from Rigel on the fine dust of the nebula.
On the picture against the blue reflecting off the dust of the nebula of the Witch Head is due not only to own the color blue Rigel, but also to the fact that only the blue light spectrum Rigel which disperses the fine grain of the nebula.
Nebula, the Witch Head is about 800 light years from our Sun.
Image: The Head Nebula Witch or IC 2118. The dust reflects more blue than red, as our earth's atmosphere where the blue sky.NB: The reflection nebulae are huge dust clouds that reflect light of several nearby stars and bright enough to make the reflecting dust. When the stars are very hot, they cause ionization of gas clouds, creating an emission nebula.
Image Data: Digitized Sky Survey, Noel Carboni
Reflection nebulae are usually blue. Reflection nebulae and emission nebulae are often combined into a single type, diffuse nebulae.
Nebula, the Witch Head is a reflection nebula, i.e. it reflects light from nearby stars.
Reflection nebulae are clouds of dust which reflect the light from just one or several nearby stars. This is the case here Rigel which floods its radiation light dust of the head of the Witch.
The stars of reflection nebulae are not hot enough to ionize the gas that composes, in contrast to emission nebulae. The distinction between these two types of nebulae was made by Edwin Hubble in 1922. Rigel is the seventh brightest star in the sky and lies between 650 and 950 light years from the Sun. The estimated absolute magnitude of -6.7 is Rigel is a blue supergiant, 55,000 times brighter than the Sun. With a diameter of about 116 million km, it is 84 times larger than the Sun. Like many supergiants, Rigel brightness varies from 3 to 30%, irregularly over a period of 25 days on average.
This variability can be explained by the pulsations of the surface of the star.
Image: The Witch Head Nebula or IC 2118.
Rigel, the star center of the photo, is the seventh brightest star in the sky and lies between 650 and 950 light years from the Sun.
Credit & Copyright: Rogelio Bernal Andreo.