Description |
The SH0ES collaboration Hubble constant determination is ∼5σ different from the Planck value, known as the Hubble tension. The accuracy of the Hubble constant measured with extragalactic Cepheids depends on robust stellar-crowding background estimation, where γ=0.24±0.05 mag is the required unaccounted systematic blending bias to resolve the Hubble tension. I will discuss a method to constrain γ by comparing the light curves amplitudes of extragalactic and MW Cepheids. A careful application of this method leads to an estimate of γ=0.013±0.057 mag. Although the obtained γ is consistent with zero, folding (in quadratures) it is ≈ 3.0σ away from aligning with Planck.
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