Friday 29 March 2019

Two doubles and a cluster with a double too!

NGC2169 is a small, but bright and compact open cluster in Orion, about 7 degrees north of Betelgeuse. Mainly blueish stars, it is an attractive object in the eyepiece and has the added bonus of a nice double star, Struve 848, with a separation of just 2,4 arc seconds, this double requires a fairly steady sky to split the pair. They both looked white, but fainter stars tend no to show much in the way of colour anyway.

Images are drawn at the eyepiece then photographed and edited in photoshop to tidy up the stars, the positions are left as seen, the text is also tidied up.








Struve (STF) 738 is a neat double star very easy to find as it is part of the loose cluster of stars that form the "head" of Orion, to the naked eye this is the faint triangle of stars that lie between Betelgeuse and Bellatrix which form the shoulders, this group then is the head.

The double itself is an uneven pair, the primary being magnitude 3.5 the secondary is 5.45 and visually the difference is very noticeable. Both stars are white in colour.



Struve 742.  An evenly matched pair of stars that lie quite close to M1, the crab nebula in Taurus, with a 4" separation, this pair are not too tricky to split, and show a pale yellow and blue colour.