Hello, I'm an expert in astronomy with a keen interest in the study of stars, their sizes, and classifications. When it comes to the comparison of the largest stars in the universe, there's always a bit of debate due to the dynamic nature of astronomical observations and the methods used to measure these vast cosmic bodies.

UY Scuti and VY Canis Majoris are both among the largest known stars by volume. However, the title of the largest star can shift as new data comes in and as measurement techniques improve.

As of my last update, UY Scuti was considered to be one of the largest stars, with an estimated radius around 1,700 times that of the Sun. VY Canis Majoris, on the other hand, has also been a contender for the title, with previous estimates placing it even larger than UY Scuti.

However, recent observations and improved measurement techniques have led to a revision in the size estimates for both stars. The current consensus is that UY Scuti is not as large as previously thought, and VY Canis Majoris may still hold the title for the largest known star by radius, although the exact figures are subject to change with ongoing research.

To provide a definitive answer, I would need to consult the most current and reliable astrophysical data, which is constantly being updated as our understanding of the cosmos evolves.

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The current thinking is that there are seven known stars larger than VY Canis Majoris, the largest of which is UY Scuti. Current models indicate that the first generation of stars were much, much larger than anything we see now. It will be quite some time before we can resolve a first generation star.read more >>