A number of people have asked me how many stars appear in the Cocoon nebula 3-frame mosaic. I use a program called Registar to link separate frames together so I can see how they all fit – and Registar will also do a “star count” for the stars in the image (I don’t think it is accurate to the level of a star ) Anyway – Registar says there are 68,200 in this image – always turns out to be a LOT less than you would guess.
Archive for the “Deep Space Objects” Category
Aug 18 2011
This pair of open clusters has a Milky Way backdrop and they are surrounded by faint emission nebulosity. They can be found in the constellation Cygnus lying just underneath the Crescent nebula region. Image taken 19th August 2009 using the Hyperstar III – 22 sub-exposures at 5-minutes per sub (equivalent to 30-minute subs on the Sky 90).
Aug 16 2011
I have no idea why I took this image of a galaxy group in Bootes on January 29th 2011. I also have no record of it in the logbook. I ran an astrometry check on it to find where it was – the bright star near the middle is magnitude 4.80. Apparently this is 19 sub-exposures at 10-minutes per sub, so for some reason I spent 3 hours of good imaging time on this one – if only I could remember why
According to the Guiness Book of Records this Quasar in the constellation Lynx is the brightest known object in our universe and who are we to argue with them [oops - see the Postscript below]! Read the rest of this entry »