Diffaktionsspikes

Diffraktionsspikes, also known as diffraction spikes, are a common optical phenomenon observed in astronomical images. They appear as straight, star-shaped lines radiating from bright points of light, such as stars or bright planets. These spikes are caused by the diffraction of light as it passes through the support structure of a telescope's secondary mirror or the edges of a camera's aperture.

The primary cause of diffraction spikes is the interaction of light with the physical components of the optical system. In reflecting telescopes, the secondary mirror is often held in place by thin vanes or struts. As light passes through the telescope, it diffracts around these supports, creating the characteristic spike pattern. Similarly, in cameras or telescopes with a circular aperture, the edges of the aperture can also cause diffraction, leading to spikes.

The number and orientation of diffraction spikes depend on the design of the telescope or camera. For instance, a telescope with four support vanes will typically produce four spikes, while a camera with a pentagonal aperture might create five. These spikes can be aesthetically pleasing in images of star fields but can also obscure fine details in astronomical objects.

To minimize diffraction spikes, some telescopes use fine wire supports for the secondary mirror or employ advanced optical designs that reduce the impact of the support structure. Additionally, post-processing techniques can be used to remove or reduce the visibility of spikes in astronomical images. Despite their potential drawbacks, diffraction spikes are a natural consequence of the optical principles governing light and are a common feature in astronomical photography.