Improved Estimates of the Distance To the Large Magellanic Cloud

Long-time Slashdot reader colinwb writes: A team of researchers has published a letter in Nature (2019) estimating the distance to the Large Magellanic Cloud' to a precision of one per cent; Arxiv (2019).

The Arxiv abstract: In the era of precision cosmology, it is essential to empirically determine the Hubble constant 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 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. Eclipsing binary systems composed of late-type stars offer the most precise and accurate way to measure the distance to the Large Magellanic Cloud. Currently the limit of the precision attainable with this technique is about two per cent, and is set by the precision of the existing calibrations of the surface brightness — colour relation. Here we report the calibration of the surface brightness-colour relation with a precision of 0.8 per cent. We use this calibration to determine the geometrical distance to the Large Magellanic Cloud that is precise to 1 per cent based on 20 eclipsing binary systems. The final distane is 49.59 +/- 0.09 (statistical) +/- 0.54 (systematic) kiloparsecs.

In 2013 a team of researchers (including several of the current researchers) published a letter in Nature (2013) which estimated the distance with a precision of two per cent; Arxiv (2013).

Another team of researchers has also posted their recent research on Arxiv (2019) in which they provide a 1% foundation for the determination of the Hubble Constant.

All the links are to abstracts; the full letters to Nature are paywalled, but the Arxiv abstracts have links to PDFs which seem to be complete and accessible.

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