For the LVAS January Observer’s Challenge I observed open cluster NGC 1545 on three separate occasions. On December 30th I observed it through my Meade 12.5” Starfinder Dob. On January 1st I observed it again with some fellow observers through an Obsession 18” Dob, and on January 15th I observed through my 4.5” Newt/Dob.
In the 12.5” I saw a pretty gathering of stars dominated by a trio of 7th and 8th magnitude stars in the middle. From this bright triangle at the center, about 40 or so 11th to 13th magnitude stars traced intricate patterns in several directions around the field of view. The view was very similar in the 18”.
In the 4.5” the view was significantly different, with fully half of the stars disappearing and none of the intricate patterns present. In fact, if I didn’t know where I was I doubt that I would mistake what I was seeing for a cluster. It’s not that well represented in a small scope.
NGC 1545 is a good object for medium to large sized amateur instruments.