Most distant astronomical objects with spectroscopic redshift determinations 4 List of objects by year of discovery that turned out to be most distantġ Gly (gigalight-year) = 1 billion light-years.3 Timeline of most distant astronomical object recordholders.Here, this distinction is indicated by a 'p' subscript for photometric redshifts. For that reason, a spectroscopic redshift is conventionally regarded as being necessary for an object's distance to be considered definitely known, whereas photometrically determined redshifts identify 'candidate' very distant sources. The former is generally both more precise and also more reliable, in the sense that photometric redshifts are more prone to being wrong due to confusion with lower redshift sources that have unusual spectra. An important distinction is whether the distance is determined via spectroscopy or using a photometric redshift technique. By their nature, very distant objects tend to be very faint, and these distance determinations are difficult and subject to errors.

This article documents the most distant astronomical objects discovered and verified so far, and the time periods in which they were so classified.ĭistances to remote objects, other than those in nearby galaxies, are nearly always inferred by measuring the cosmological redshift of their light.

Redshift data types