F200DB-045 is a candidate high-redshift galaxy, with an estimated redshift of approximately z = 20.4,[1][2] corresponding to 168 million years after the Big Bang.[3] If confirmed, it would be one of the earliest and most distant known galaxies observed.
Nonetheless, the redshift value of the galaxy presented by the procedure in one study[1] may differ from the values presented in other studies using different procedures.[2][4]
Only a photometric redshift has been determined for F200DB-045; follow-up spectroscopic measurements will be required to confirm the redshift (see spectroscopic redshift). Spectroscopy could also determine the chemical composition, size and temperature of the galaxy.
If confirmed, the galaxy may have existed in its star formation phase in the early universe, when it would have been composed mostly of dust as well as young and massive population III stars.