Astr110 Photography Projects, Fall 2004

Orion Nebula, Meredith Mele and Matt Vriesman

In the sword of the constellation Orion, 1,500 light years from Earth, lies the Orion Nebula. This wispy, vibrant cloud of glowing gas is one of the most famous emission nebulas (also known as an ionization nebula). It is considered an emission nebula because a neighboring hot star floods it with ultraviolet photons that can ionize hydrogen atoms, thus causing it to glow. Nebulae in this category are usually red, as is the Orion Nebula, because hydrogen emits predominately in red wavelengths. Despite its impressive beauty, the Orion Nebula appears as only a small, cloudy patch to the naked eye.

Pictured above is the center of the nebula, its brightest stars and the pale red cloud that surrounds them. The long, dagger shaped stars are actually imperfections in the photography. Because many of the stars are faint and difficult to see, a long exposure time was used. However, many areas became over-exposed causing the stars to bleed in the photograph.

References: Bennet, Jeffrey "The Cosmic Perspective" http://nineplanets.org/twn/n1976x.html