Collaboration between Swinburne and CSIRO
Researchers from the Swinburne University of Technology and Australia’s CSIRO have recently combined optical observations with data from a neutron‑star merger detected via gravitational waves. Their aim is to derive a more direct measurement of the Universe’s expansion rate, known as the Hubble constant.
Gravitational‑wave based distance measurement
The collision of two neutron stars produced a strong gravitational‑wave signal together with a bright electromagnetic counterpart. By comparing the arrival times of both signals, the distance to the event can be precisely determined, providing an independent estimate of the Hubble constant.
Long‑standing tension in cosmology
For more than a decade, values obtained from the cosmic microwave background and those derived from local supernova observations have disagreed significantly. This new approach offers a third, independent pathway that could help resolve the discrepancy.
Preliminary results and next steps
Initial calculations place the constant between the previously conflicting numbers, suggesting that systematic uncertainties in existing techniques may be at play. Additional neutron‑star merger detections are planned to improve the statistical sample and reduce uncertainties.
Implications for the future
A tighter constraint on the Hubble constant is essential for models of dark energy and the long‑term fate of the cosmos. The synergy of gravitational‑wave and electromagnetic data opens a promising new window for precision cosmology.