R Serpentis is a

Mira variable Mira variables (named for the prototype star Mira) are a class of pulsating stars characterized by very red colours, pulsation periods longer than 100 days, and amplitudes greater than one magnitude in infrared and 2.5 magnitude at visual wavele ...

type star in the equatorial constellation of

Serpens Serpens ( grc, , , the Serpent) is a constellation in the northern celestial hemisphere. One of the 48 constellations listed by the 2nd-century astronomer Ptolemy, it remains one of the 88 modern constellations designated by the International ...

. It ranges between apparent magnitude 5.16 and 14.4, and spectral types M5e to M8e, over a period of 356.41 days. The variability of this star was discovered in 1826 by Karl Ludwig Harding.

References

{{DEFAULTSORT:R Serpentis M-type giants Mira variables Serpens (constellation) Durchmusterung objects 141850 077615 5894 Serpentis, R