what creates the "star points" in telescope pictures of stars? it's a basic question. e.g. see this hi-rez Hubble Deep Space pic: http://upload.wikimedia.org/wikipedia/commons/9/9b/Hs-2004-07-a-full_jpgNR.jpg i count about three bright objects with pointy cross-like projections from the bright object. i take it that these three objects are stars in the foreground (the Milky Way) and all of the other objects are, i assume distant galaxies well beyond distances in the Milky Way. so what causes those pointy projections? why four points? why are they all oriented in the same direction? (i presume it has something to do with the orientation of the lens and if the Hubble were rotated a little, the points would move relative to the background.) since the stars and the galaxies are all, pretty much, at a focus of infinity, why are they different? why shouldn't a bright, dot-like galaxy, have similar pointy projections?