Godzilla (star)

Godzilla is a variable star in the Sunburst galaxy at redshift z = 2.37 (or 10.9 billion light years from Earth), observed through the gravitational lens PSZ1 G311.65-18.48. It was originally identified in the NW arc as a possible transient event in images taken with the Hubble Space Telescope (HST).

As of October 2022, it is the most luminous star that can be currently observed. This is possible because the star is believed to be undergoing an episode of temporary increased luminosity that has lasted at least seven years, combined with an estimated magnification of at least a factor of 2000.

Some spectral features in Godzilla resemble those of other variable stars in the Milky Way Galaxy such as Eta Carinae, suggesting that Godzilla could be close to the end of its life. Godzilla is believed to be going through an episode similar to the Great Eruption of Eta Carinae in the 19th century, during which the star was likely among the brightest in the universe at about.

The extreme magnification of Godzilla is partially due to a nearby substructure, probably a dwarf galaxy, not seen in the HST images (but recently detected in new JWST images), that is also close to the critical curve of the cluster. This unobserved substructure is believed to be dominated by dark matter.

Godzilla is named after the most famous Kaiju and makes reference to its monstrous nature. Other Kaiju stars include Mothra, which shares many of the characteristics of Godzilla.