I saw an article on using a ball bearing as an artificial star years ago.  Very interesting!  I've never tried it before.   Date: Tue, 11 Feb 2014 09:57:29 -0700 From: "Erik Hansen" <erikhansen@thebluezone.net> To: Utah-Astronomy@mailman.xmission.com Subject: [Utah-astronomy] Collimation of SCT with artificial star Message-ID:     <6e6494c0a7aa8d9f9f3c1de1a4f8a5d8.squirrel@webmail.thebluezone.net> Content-Type: text/plain;charset=iso-8859-1 http://www.leif.org/mikael/collimation.html