The Hubble Legacy Field is an image of a small region of

space Space is the boundless three-dimensional extent in which objects and events have relative position and direction. In classical physics, physical space is often conceived in three linear dimensions, although modern physicists usually con ...

in the constellation

Fornax Fornax () is a constellation in the southern celestial hemisphere, partly ringed by the celestial river Eridanus. Its name is Latin for furnace. It was named by French astronomer Nicolas Louis de Lacaille in 1756. Fornax is one of the 88 mod ...

, containing an estimated 265,000

galaxies A galaxy is a system of stars, stellar remnants, interstellar gas, dust, dark matter, bound together by gravity. The word is derived from the Greek ' (), literally 'milky', a reference to the Milky Way galaxy that contains the Solar System. ...

. The original release was composed of

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 ver ...

data accumulated over a 16-year period. Looking back approximately 13 billion years (between 400 and 800 million years after 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 t ...

) it has been used to search for galaxies that existed at that time. The image was taken in a section of the sky with a low density of bright stars in the near-field, allowing much better viewing of dimmer, more distant objects. It builds on the data collected for the

Hubble Ultra-Deep Field The Hubble Ultra-Deep Field (HUDF) is a deep-field image of a small region of space in the constellation Fornax, containing an estimated 10,000 galaxies. The original data for the image was collected by the Hubble Space Telescope from Septemb ...

, the

Hubble eXtreme Deep Field The Hubble Ultra-Deep Field (HUDF) is a deep-field image of a small region of space in the constellation Fornax, containing an estimated 10,000 galaxies. The original data for the image was collected by the Hubble Space Telescope from Septemb ...

and the

Great Observatories Origins Deep Survey The Great Observatories Origins Deep Survey, or GOODS, is an astronomical survey combining deep observations from three of NASA's Great Observatories: the Hubble Space Telescope, the Spitzer Space Telescope, and the Chandra X-ray Observatory, alo ...

. Located southwest of Orion in the southern-hemisphere constellation

, the approximately rectangular image is about 25

arcminutes A minute of arc, arcminute (arcmin), arc minute, or minute arc, denoted by the symbol , is a unit of angular measurement equal to of one degree. Since one degree is of a turn (or complete rotation), one minute of arc is of a turn. The nau ...

to an edge. This is almost the

angular diameter The angular diameter, angular size, apparent diameter, or apparent size is an angular distance describing how large a sphere or circle appears from a given point of view. In the vision sciences, it is called the visual angle, and in optics, it i ...

of a full moon viewed from

Earth Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's surf ...

(which is about 31 arcminutes, or a half a degree). The images and data release were announced on May 2, 2019, by NASA.

Planning

As with the earlier fields, this one was required to contain very little emission from our galaxy, with little

Zodiacal dust The interplanetary dust cloud, or zodiacal cloud (as the source of the zodiacal light), consists of cosmic dust (small particles floating in outer space) that pervades the space between planets within planetary systems, such as the Solar System ...

. The field was also required to be in a range of

declinations In astronomy, declination (abbreviated dec; symbol ''δ'') is one of the two angles that locate a point on the celestial sphere in the equatorial coordinate system, the other being hour angle. Declination's angle is measured north or south of t ...

such that it could be observed both by southern hemisphere instruments, such as the

Atacama Large Millimeter Array The Atacama Large Millimeter/submillimeter Array (ALMA) is an astronomical interferometer of 66 radio telescopes in the Atacama Desert of northern Chile, which observe electromagnetic radiation at millimeter and submillimeter wavelengths. Th ...

, and northern hemisphere ones, such as those located on

Hawaii Hawaii ( ; haw, Hawaii or ) is a state in the Western United States, located in the Pacific Ocean about from the U.S. mainland. It is the only U.S. state outside North America, the only state that is an archipelago, and the only ...

. It was ultimately decided to observe a section of the

Chandra Deep Field South The Chandra Deep Field South (CDF-S) is an image taken by the Chandra X-ray Observatory satellite. The location was chosen because, like the Lockman Hole, it is a relatively clear "window" through the ubiquitous clouds of neutral hydrogen gas in ...

, due to existing deep X-ray observations from

Chandra X-ray Observatory The Chandra X-ray Observatory (CXO), previously known as the Advanced X-ray Astrophysics Facility (AXAF), is a Flagship-class space telescope launched aboard the during STS-93 by NASA on July 23, 1999. Chandra is sensitive to X-ray sources ...

and two interesting objects already observed in the Great Observatories Origins Deep Survey sample at the same location: a redshift 5.8 galaxy and a supernova. The coordinates of the field are

right ascension Right ascension (abbreviated RA; symbol ) is the angular distance of a particular point measured eastward along the celestial equator from the Sun at the March equinox to the ( hour circle of the) point in question above the earth. When pai ...

declination In astronomy, declination (abbreviated dec; symbol ''δ'') is one of the two angles that locate a point on the celestial sphere in the equatorial coordinate system, the other being hour angle. Declination's angle is measured north or south of t ...

(

J2000 In astronomy, an epoch or reference epoch is a moment in time used as a reference point for some time-varying astronomical quantity. It is useful for the celestial coordinates or orbital elements of a celestial body, as they are subject to pertu ...

Observations

The Hubble Legacy Field is composed of data from 7,500 exposures, with a total exposure time of 250 days.

Video

References

External links

Scalable interactive Hubble Legacy Field. Wikisky.org
at HubbleSite Hubble Space Telescope images Physical cosmology Sky regions Fornax Astronomy image articles 2019 works 2010s photographs {{physical-cosmology-stub

Planning

Observations

Video

See also

References

External links