Testing the QGP Star Hypothesis: The oMEGACat BH-2 System as a Candidate Color-Superconducting Quark-Gluon Plasma Star

Abstract

The recent discovery of a long-period binary system in the globular cluster $\omega$ Centauri, oMEGACat BH-2 \citep{Whitaker2026}, provides an unprecedented opportunity to probe the true nature of compact dark objects. The system's massive, dark companion has been inferred to have a mass of $4.46_{-1.01}^{+1.22} M_\odot$, which places it in the ``mass gap'' between neutron stars and the canonical stellar-mass black holes. In this Letter, we explore the hypothesis that the oMEGACat BH-2 companion is not a classical black hole, but a stable, self-bound Quark-Gluon Plasma (QGP) star, as described by recent general relativistic models that incorporate Nonlinear Electrodynamics (NLED) and the asymptotic freedom of Quantum Chromodynamics (QCD) \citep{Mosquera2025}. We compare the inferred mass of the companion with the novel Mass-Radius ($M$-$R$) relation predicted by the QGP star model. We find that the inferred mass of the $\omega$ Centauri object lies squarely within the wide mass spectrum predicted for hypermassive QGP stars ($0$ to $>7$ $M_\odot$). Although this consistency is not enough for claiming evidence, it suggests that oMEGACat BH-2 may be the first observed candidate for a QGP star, representing a stable, non-singular end-state of stellar collapse. We argue that future astrometric monitoring with JWST and radio-telescopes like FAST and SKA can further constrain the oMEGACat BH-2 orbital parameters. Meanwhile, gravitational-wave follow-ups for the $f$ and $g$ modes by observatories like LIGO, VIRGO, KAGRA, LISA, ET and CE can be crucial for distinguishing a classical black hole from the ``gravitational eternally collapsing `kompact' object'' (\GECKO) state of our QGP star model.