Universe's expansion rate refined using supernova 'twins' ⚡ экспресс
Using the 'twin' method among Type Ia supernovae—explosions with identical characteristics—scientists uncovered inaccuracies in the Pantheon+ and CCHP catalogs: an underestimation of dust reddening. A careful selection of 12 supernovae with high-precision distances, tied to Cepheids and JAGB stars, gave a Hubble constant of 72.4 km/s/Mpc. This confirms the 'Hubble tension'—the discrepancy between local and global expansion rates of the Universe. The work is like cleaning the static from old cosmic recordings to hear the true rhythm of the cosmos.
Type Ia supernovae are like light bulbs of a fixed wattage: the dimmer the light, the farther the source. Such supernovae serve as distance markers to remote galaxies. But cosmic dust, like a dirty window, dims and reddens the light, messing up the calculations. Astronomers led by Adam Riess sidestepped the problem: they compared only 'twins'—supernovae with identical properties, whose light traveled through similarly dusty regions. It's like gauging distance by lamps hidden in identical lampshades. The new data yield a universe expansion rate of about 72.4 km/s per megaparsec (that's 3.26 million light-years). That's noticeably faster than the ancient light from the Big Bang predicts. The discrepancy, known as the 'Hubble tension', has now grown even stronger.
🎯 It was precisely with type Ia supernovae that the accelerating expansion of the universe was discovered in 1998—a Nobel Prize-winning breakthrough.
🎬 Confirmation of the Hubble tension makes sci-fi scenarios where physical laws evolve just a little less fictional.