The James Webb Space Telescope (JWST) has conducted measurements of the expansion rate of the Universe, confirming previous findings by the Hubble Space Telescope. This agreement indicates that there is no error in the Hubble data, leaving the cosmological conundrum known as the Hubble tension unresolved.
The Hubble tension refers to the discrepancy between different measurement methods used to determine the expansion rate, often referred to as the Hubble Constant or H0. These methods include examining relics of the early Universe and measuring the distances to objects with known intrinsic brightness. The former typically suggests an expansion rate of around 67 kilometers per second per megaparsec, while the latter suggests around 73 kilometers per second per megaparsec.
These measurements have been repeatedly performed, minimizing the chances of error. However, the possibility remains that some of the data might be misleading. In the case of measuring the distances using Cepheid variable stars, the Hubble Space Telescope has been the primary source of data, but its visible-wavelength resolution is limited due to Earth’s atmosphere.
To overcome this limitation, the JWST, a powerful infrared telescope, was employed. A team led by astrophysicist Adam Riess of the Space Telescope Science Institute and Johns Hopkins University used JWST to observe Cepheids in other galaxies. The collected data was in agreement with the Hubble observations, suggesting that any uncertainties in the Hubble data do not account for the Hubble tension.
The cause of the tension remains unknown, but one of the leading contenders is dark energy, a mysterious force responsible for the accelerating expansion of the Universe. With the JWST providing further evidence, scientists hope to gain insights into this cosmic mystery.
The results of this study have been accepted into The Astrophysical Journal and can be found on arXiv.
– The Astrophysical Journal