A 5% measurement of the Hubble constant from Type II supernovae

The most stringent local measurement of the Hubble-Lema^itre constant from Cepheid-calibrated Type Ia supernovae (SNe~Ia) differs from the value inferred via the cosmic microwave background radiation ({\it Planck}$+\mathrm{\Lambda }$CDM) by $\sim 5\sigma$. This so-called “Hubble tension” has been confirmed by other independent methods, and thus does not appear to be a possible consequence of systematic errors. Here, we continue upon our prior work of using Type II supernovae to provide another, largely-independent method to measure the Hubble-Lema^itre constant. From 13 SNe~II with geometric, Cepheid, or tip of the red giant branch (TRGB) host-galaxy distance measurements, we derive H$0= 75.4^{+3.8}{-3.7}$kms$^{-1}$Mpc$^{-1}$ (statistical errors only), consistent with the local measurement but in disagreement by $\sim 2.0\sigma$ with the {\it Planck}$+\mathrm{\Lambda }$CDM value. Using only Cepheids ($N=7$), we find H${}_0=77.6_{-4.8}^{+5.2}$,km,s${}^{-1}$,Mpc${}^{-1}$, while using only TRGB ($N=5$), we derive H${}_0=73.1_{-5.3}^{+5.7}$,km,s${}^{-1}$,Mpc${}^{-1}$. Via 13 variants of our dataset, we derive a systematic uncertainty estimate of 1.5,km,s${}^{-1}$,Mpc${}^{-1}$. The median value derived from these variants differs by just 0.3,km,s${}^{-1}$,Mpc${}^{-1}$ from that produced by our fiducial model. Because we only replace SNe~Ia with SNe~II – and we do not find statistically significant difference between the Cepheid and TRGB H${}_0$ measurements – our work reveals no indication that SNe~Ia or Cepheids could be the sources of the “H${}_0$ tension.” We caution, however, that our conclusions rest upon a modest calibrator sample; as this sample grows in the future, our results should be verified.