2025RAA....25e5016Y

The central compact object XMMU J173203.3-344518 in the supernova remnant HESS J1731-347 challenges conventional neutron star models due to its low mass $M=0.7{7}_{-0.17}^{+0.20}{M}_{\odot }$and high redshifted surface temperature ${T}_{s}^{\infty }=15{6}_{-6}^{+6}$ eV ($1.8{1}_{-0.07}^{+0.07}\times 1{0}^{6}\,{\rm{K}}$). We investigate the observational properties of XMMU J173203.3-344518 within a color-flavor-locked(CFL) phase strange star model. We construct a thermal evolution model of the CFL phase strange star, along with heating due to the viscous dissipation of r-mode oscillations. Employing one of the most widely used quark matter equations of state, we characterize the star properties by the strange quark mass (m_s), effective bag constant (B_eff), perturbative QCD correction (a₄), and pairing gap (Δ). Our analysis demonstrates that the observed properties of XMMU J173203.3344518 can be explained by r-mode heating with a CFL strange star, provided that the initial spin period is shorter than 18 ms. We constrain the r-mode saturation amplitude to 8 × 10^–3-1.4 × 10^–2 and predict a current spin period of 6-9 ms for an initial period of 1 ms. This rapid rotation is consistent with the absence of detected pulsations. The r-mode instability window remains robust across a wide range of pairing gap values (5-200 MeV), providing a reliable framework for interpretation regardless of microscopic uncertainties. Our results support the identification of XMMU J173203.3344518 as a rapidly rotating, low-mass CFL phase strange star, demonstrating the importance of r-mode heating in the thermal evolution of compact objects with exotic dense matter.