If you are looking to add some new variables to your observing list, then here are some stars you may want to consider.
Delphinus contains two easy to find variables: EU Del and U Del. Both EU Del and U Del are pulsating red giants and both are classified as semi-regulars (SRB). EU Del has an amplitude of 5.4 – 6.7 and a period of about 59 days. U Del has an amplitude of 6.1 – 7.6 and a period of about 120 days.
In the nearby constellation of Serpens, the bright variable Tau 4 Ser can be found not far from R Serpentis. Tau 4 Ser is another semi-regular variable (SRB) with an amplitude of 5.9 – 7.1, and a period of 87 days.
Below are finder charts for these stars, which have been adapted from the BAA Charts.