R Leonis is a fine variable; the brightness and the colour are quite remarkable.

The star is one of the earliest to be established as a long-range variable, in 1782. Its range usually fluctuates from about 5, perhaps even 4.5, to a minimum of about 10 or 11. The average period is 310 days.

The star has an unusually deep red, sometimes described as purple and as it is encircled by brighter white stars (18, 19, 21 Leo) the contrast is even greater.

The star is six degrees west of alpha Leo; move one and a half binocular fields west from alpha to bring in omicron.

R is in the same field, on the eastern edge.