This article documents the most distant astronomical objects discovered and verified so far, and the time periods in which they were so classified. For comparisons with the

light travel distance Distance measures are used in physical cosmology to give a natural notion of the distance between two objects or events in the universe. They are often used to tie some ''observable'' quantity (such as the luminosity of a distant quasar, the ...

of the astronomical objects listed below, the

age of the universe In physical cosmology, the age of the universe is the time elapsed since the Big Bang. Astronomers have derived two different measurements of the age of the universe: a measurement based on direct observations of an early state of the universe, ...

since the

Big Bang The Big Bang event is a physical theory that describes how the universe expanded from an initial state of high density and temperature. Various cosmological models of the Big Bang explain the evolution of the observable universe from the ...

is currently estimated as 13.787±0.020 Gyr. Distances to remote objects, other than those in nearby galaxies, are nearly always inferred by measuring the

cosmological redshift Hubble's law, also known as the Hubble–Lemaître law, is the observation in physical cosmology that galaxies are moving away from Earth at speeds proportional to their distance. In other words, the farther they are, the faster they are moving a ...

of their light. By their nature, very distant objects tend to be very faint, and these distance determinations are difficult and subject to errors. An important distinction is whether the distance is determined via

spectroscopy Spectroscopy is the field of study that measures and interprets the electromagnetic spectra that result from the interaction between electromagnetic radiation and matter as a function of the wavelength or frequency of the radiation. Matter wa ...

or using a

photometric redshift A photometric redshift is an estimate for the recession velocity of an astronomical object such as a galaxy or quasar, made without measuring its spectrum. The technique uses photometry (that is, the brightness of the object viewed through various ...

technique. 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 may have unusual spectra. For that reason, a

spectroscopic redshift In physics, a redshift is an increase in the wavelength, and corresponding decrease in the frequency and photon energy, of electromagnetic radiation (such as light). The opposite change, a decrease in wavelength and simultaneous increase in fr ...

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. Here, this distinction is indicated by a "p" subscript for photometric redshifts.

Most distant spectroscopically-confirmed objects

Candidate most distant objects

Since the beginning of the

James Webb Space Telescope The James Webb Space Telescope (JWST) is a space telescope which conducts infrared astronomy. As the largest optical telescope in space, its high resolution and sensitivity allow it to view objects too old, distant, or faint for the Hubble Spa ...

's (JWST) science operations in June 2022, numerous distant galaxies far beyond what could be seen by the

Hubble Space Telescope The Hubble Space Telescope (often referred to as HST or Hubble) is a space telescope that was launched into low Earth orbit in 1990 and remains in operation. It was not the first space telescope, but it is one of the largest and most versa ...

(z = 11) have been discovered thanks to the JWST's capability of seeing far into the

infrared Infrared (IR), sometimes called infrared light, is electromagnetic radiation (EMR) with wavelengths longer than those of visible light. It is therefore invisible to the human eye. IR is generally understood to encompass wavelengths from around ...

. Previously in 2012, there were about 50 possible objects z = 8 or farther, and another 100 candidates at z = 7, based on photometric redshift estimates released by the Hubble eXtreme Deep Field (XDF) project from observations made between mid-2002 and December 2012. Some objects included here have been observed spectroscopically, but had only one emission line tentatively detected, and are therefore still considered candidates by researchers.

List of most distant objects by type

Timeline of most distant astronomical object recordholders

Objects in this list were found to be the most distant object at the time of determination of their distance. This is frequently not the same as the date of their discovery. Distances to astronomical objects may be determined through

parallax Parallax is a displacement or difference in the apparent position of an object viewed along two different lines of sight and is measured by the angle or semi-angle of inclination between those two lines. Due to foreshortening, nearby objects ...

measurements, use of standard references such as

cepheid variable A Cepheid variable () is a type of star that pulsates radially, varying in both diameter and temperature and producing changes in brightness with a well-defined stable period and amplitude. A strong direct relationship between a Cepheid varia ...

s or

Type Ia supernova A Type Ia supernova (read: "type one-A") is a type of supernova that occurs in binary systems (two stars orbiting one another) in which one of the stars is a white dwarf. The other star can be anything from a giant star to an even smaller white ...

s, or

redshift In physics, a redshift is an increase in the wavelength, and corresponding decrease in the frequency and photon energy, of electromagnetic radiation (such as light). The opposite change, a decrease in wavelength and simultaneous increase in f ...

measurement.

Spectroscopic redshift In physics, a redshift is an increase in the wavelength, and corresponding decrease in the frequency and photon energy, of electromagnetic radiation (such as light). The opposite change, a decrease in wavelength and simultaneous increase in fr ...

measurement is preferred, while

measurement is also used to identify candidate high redshift sources. The symbol ''z'' represents redshift.

List of objects by year of discovery that turned out to be most distant

This list contains a list of most distant objects by year of discovery of the object, not the determination of its distance. Objects may have been discovered without distance determination, and were found subsequently to be the most distant known at that time. However, object must have been named or described. An object like

OJ 287 OJ 287 is a BL Lac object 3.5 billion light-years from Earth that has produced quasi-periodic optical outbursts going back approximately 120 years, as first apparent on photographic plates from 1891. Seen on photographic plates since at least 18 ...

is ignored even though it was detected as early as 1891 using photographic plates, but ignored until the advent of radiotelescopes.

Notes

References

{{DEFAULTSORT:Astronomical objects, List of most distant Most distant Astronomical objects, most distant