Start patterns on images

[taisha99]

Hi<br />Simple question. Why when I look at stars, do I see "star" patterns. This also is obvious on most (all?) images. Why should a point show as a "star" shape ?<br /><br />Ged

 

[bbrock]

Simple Answer<br /><br />When bright stars are imaged with a reflector telescope, the secondary mirror support spider vanes show up as four star points on the brighter star images. This does not occur if the image is captured with a clear aperture refractor or cassigrain scope. <br /><br />Bill

 

[igorsboss]

With the advent of CCD cameras, it was discovered that the most distant stars are actually square.