This is a difficult double to split. This is due to two factors. Firstly they are only 30" apart, which is right at the resolution limit for 10x binoculars. Secondly, the primary star shines at magnitude 4.0, whilst its companion is only magnitude 6.5, a 10 times difference in brightness. These two factors make Iota a challenging pair to split. It may appear like a slight optical flare coming off the brighter star and can easily get overlooked.

Facts about Iota Cancri by Keith Turnecliff

Binoculars with a magnification of x15 and above will make a difference in splitting these two stars.

This star chart represents a view from Long Itchington for mid March at 10pm.
Credits: Image courtesy of Starry Night Pro Plus 8, researched and implemented by Keith Turnecliff.