In a previous paper , using an equation of state of dense matter representing a fluid of Skyrmions we constructed the corresponding non-rotating compact-star models in hydrostatic equilibrium ; these are mostly fluid stars ( the Skyrmion fluid ) thus naming them Skyrmion Stars .
Here we generalize our previous calculations by constructing equilibrium sequences of rotating Skyrmion stars in general relativity using the computer code { \it RNS } developed by Stergioulas .
We calculated their masses and radii to be 0.4 \leq M / M _ { \odot } \leq 3.45 , and 13.0 { km } \leq R \leq 23.0 { km } , respectively ( R being the circumferential radius of the star ) .
The period of the maximally rotating Skyrmion stars is calculated to be 0.8 { ms } \leq P \leq 2.0 { ms } .
We find that a gap ( the height between the star surface and the inner stable circular orbit ) starts to appear for M \sim 2.0 M _ { \odot } .
Specifically , the Skyrmion star mass range with an existing gap is calculated to be 1.8 < M / M _ { \odot } < 3.0 with the corresponding orbital frequency 0.8 { kHz } < \nu _ { ISCO } < 1.3 { kHz } .
We apply our model to the 4U 1820-30 low mass X-ray binary and suggest a plausible Skyrmion star candidate in the 4U 1636-53 system .
We discuss the difficulties encountered by our model in the 4U 0614+09 case with the highest known Quasi-Periodic Oscillation frequency of 1329 Hz .
A comparative study of Skyrmion stars and models of neutron stars based on recent/modern equations of state is also presented .