List of largest stars

Although red supergiants are often considered the largest stars, some other star types have been found to temporarily increase significantly in radius, such as during LBV eruptions or luminous red novae. Luminous red novae appear to expand extremely rapidly, reaching thousands to tens of thousands of solar radii within only a few months, significantly larger than the largest red supergiants. All the sizes stated in these lists have inaccuracies and may be disputed. The lists are still a work in progress and parameters are prone to change. ==Caveats==

Various issues exist in determining accurate radii of the largest stars, which in many cases do display significant errors. The following lists are generally based on various considerations or assumptions; these include: • Stellar radii or diameters are usually derived only approximately using the Stefan–Boltzmann law for the deduced stellar luminosity and effective surface temperature. • Stellar distances, and their errors, for most stars, remain uncertain or poorly determined. • Many extended supergiant atmospheres also significantly change in size over time, regularly or irregularly pulsating over several months or years as variable stars. This makes adopted luminosities poorly known and may significantly change the quoted radii. • Other direct methods for determining stellar radii rely on lunar occultations or from eclipses in binary systems. This is only possible for a very small number of stars. • Many distance estimates for red supergiants come from stellar cluster or association membership, because it is difficult to calculate accurate distances for red supergiants that are not part of any cluster or association. • In these lists are some examples of extremely distant extragalactic stars, which may have slightly different properties and natures than the currently largest known stars in the Milky Way. For example, some red supergiants in the Magellanic Clouds are suspected to have slightly different limiting temperatures and luminosities. Such stars may exceed accepted limits by undergoing large eruptions or changing their spectral types over just a few months (or potentially years). ==Lists==

The following lists show the largest known stars based on the host galaxy. Milky Way Magellanic Clouds Andromeda (M31) and Triangulum (M33) galaxies Other galaxies (within the Local Group) Outside the Local Group (inside the Virgo supercluster) Outside the Virgo supercluster Note that this list does not include the candidate JWST dark stars, with estimated radii of up to or quasi-stars, with theoretical models suggesting that they could reach radii of up to . Transient events During some transient events, such as red novae or LBV eruptions the star's radius can increase by a significant amount. SN Progenitors Stars with poorly-defined radii ==Largest stars by apparent size==

The following list include the largest stars by their apparent size (angular diameter) as seen from Earth. The unit of measurement is the milliarcsecond (mas), equivalent to . Stars with angular diameters larger than 13milliarcseconds are included. ==See also==