A distance to the Large Magellanic Cloud that is precise to one per cent.

In the era of precision cosmology, it is essential to determine the Hubble constant empirically with an accuracy of one per cent or better. At present, the uncertainty on this constant is dominated by the uncertainty in the calibration of the Cepheid period-luminosity relationship (also known as the Leavitt law). The Large Magellanic Cloud has traditionally served as the best galaxy with which to calibrate Cepheid period-luminosity relations, and as a result has become the best anchor point for the cosmic distance scale.

An eclipsing-binary distance to the Large Magellanic Cloud accurate to two per cent.

In the era of precision cosmology, it is essential to determine the Hubble constant to an accuracy of three per cent or better. At present, its uncertainty is dominated by the uncertainty in the distance to the Large Magellanic Cloud (LMC), which, being our second-closest galaxy, serves as the best anchor point for the cosmic distance scale. Observations of eclipsing binaries offer a unique opportunity to measure stellar parameters and distances precisely and accurately.