astronomy Astronomy () is a natural science that studies celestial objects and phenomena. It uses mathematics, physics, and chemistry in order to explain their origin and evolution. Objects of interest include planets, moons, stars, nebulae, g ...

, first light is the first use of a

telescope A telescope is a device used to observe distant objects by their emission, absorption, or reflection of electromagnetic radiation. Originally meaning only an optical instrument using lenses, curved mirrors, or a combination of both to observ ...

(or, in general, a new instrument) to take an astronomical image after it has been constructed. This is often not the first viewing using the telescope; optical tests will probably have been performed to adjust the components.

Characteristics

The first light image is normally of little scientific interest and is of poor quality, since the various telescope elements are yet to be adjusted for optimum efficiency. Despite this, a first light is always a moment of great excitement, both for the people who design and build the telescope and for the astronomical community, who may have anticipated the moment for many years while the telescope was under construction. A well-known and spectacular astronomical object is usually chosen as a subject.

Historical examples

The famous

Hale Telescope The Hale Telescope is a , 3.3 reflecting telescope at the Palomar Observatory in San Diego County, California, US, named after astronomer George Ellery Hale. With funding from the Rockefeller Foundation in 1928, he orchestrated the planning, de ...

of Palomar Observatory saw first light on 26 January 1949, targeting

NGC 2261 NGC 2261 (also known as Hubble's Variable Nebula or Caldwell 46) is a variable nebula located in the constellation Monoceros. The nebula is illuminated by the star R Monocerotis (R Mon), which is not directly visible itself. Observing history N ...

under the direction of American astronomer

Edwin Powell Hubble Edwin Powell Hubble (November 20, 1889 – September 28, 1953) was an American astronomer. He played a crucial role in establishing the fields of extragalactic astronomy and observational cosmology. Hubble proved that many objects previous ...

. The image was published in many magazines and is available on Caltech Archives. The

Isaac Newton Telescope The Isaac Newton Telescope or INT is a 2.54 m (100 in) optical telescope run by the Isaac Newton Group of Telescopes at Roque de los Muchachos Observatory on La Palma in the Canary Islands since 1984. Originally the INT was situated at He ...

had two first lights: one in England in 1965 with its original mirror, and another in 1984 at La Palma island. The second first light was done with a video camera that showed the

Crab Pulsar The Crab Pulsar (PSR B0531+21) is a relatively young neutron star. The star is the central star in the Crab Nebula, a remnant of the supernova SN 1054, which was widely observed on Earth in the year 1054.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 vers ...

in 1990 soon gave way to initial disappointment when a flaw prevented adjustments for proper operation. The expected first light image quality was finally achieved after a 1993 servicing mission by Space Shuttle ''Endeavour''. The

Large Binocular Telescope The Large Binocular Telescope (LBT) is an optical telescope for astronomy located on Mount Graham, in the Pinaleno Mountains of southeastern Arizona, United States. It is a part of the Mount Graham International Observatory. When using both ...

had its first light with a single primary mirror on 12 October 2005, which was a view of

NGC 891 NGC 891 (also known as Caldwell 23, the Silver Sliver Galaxy, and the Outer Limits Galaxy) is an edge-on unbarred spiral galaxy about 30 million light-years away in the constellation Andromeda. It was discovered by William Herschel on October ...

. The second primary mirror was installed in January 2006 and became fully operational in January 2008. The

Gran Telescopio Canarias The Gran Telescopio Canarias (GranTeCan or GTC) is a reflecting telescope located at the Roque de los Muchachos Observatory on the island of La Palma, in the Canaries, Spain. It is the world's largest single-aperture optical telescope. Constr ...

had a first light image of Tycho 1205081 on 14 July 2007. The

IRIS Iris most often refers to: *Iris (anatomy), part of the eye *Iris (mythology), a Greek goddess * ''Iris'' (plant), a genus of flowering plants * Iris (color), an ambiguous color term Iris or IRIS may also refer to: Arts and media Fictional ent ...

solar space observatory achieved first light on 17 July 2013. The PI noted:

"The quality of images and spectra we are receiving from IRIS is amazing. This is just what we were hoping for ..."

On 4 February 2022, the first light viewed by the James Webb Space Telescope (JWST) was from the star

HD 84406 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 ...

for the purpose of testing and aligning the focus of the telescope's 18 mirrors. On 11 February 2022. ''

The New York Times ''The New York Times'' (''the Times'', ''NYT'', or the Gray Lady) is a daily newspaper based in New York City with a worldwide readership reported in 2020 to comprise a declining 840,000 paid print subscribers, and a growing 6 million paid ...

'' reported that "first light" images from the James Webb Space Telescope were released - as well as a relate
NASA alignment video (2/11/2022; 3:00)
On 6 July 2022, NASA released a test image from the JWST's Fine Guidance Sensor. NASA released the first official JWST image on 11 July 2022. Later, in an official ceremony, the first collection of five JWST science images were released on Tuesday, 12 July 2022 (NASA-TV live; 10:30 am/et/usa).

Gallery

File:NGC 5317 (also NGC 5364).jpg,

Very Large Telescope The Very Large Telescope (VLT) is a telescope facility operated by the European Southern Observatory on Cerro Paranal in the Atacama Desert of northern Chile. It consists of four individual telescopes, each with a primary mirror 8.2 m acro ...

's wide field imager VIMOS takes its first light image of NGC 5364. File:Hubble First Light, First Released Image (STScI-1990-04a).png,

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 vers ...

's first light with its impaired WFPC, 1990 File:Tarantula Nebula TRAPPIST.jpg, First light of the

Tarantula Nebula The Tarantula Nebula (also known as 30 Doradus) is a large H II region in the Large Magellanic Cloud (LMC), forming its south-east corner (from Earth's perspective). Discovery The Tarantula Nebula was observed by Nicolas-Louis de Lacaille durin ...

TRAPPIST The Trappists, officially known as the Order of Cistercians of the Strict Observance ( la, Ordo Cisterciensis Strictioris Observantiae, abbreviated as OCSO) and originally named the Order of Reformed Cistercians of Our Lady of La Trappe, are a ...

File:WISPR first light image.png, First light of WISPR on the

Parker Solar Probe The Parker Solar Probe (PSP; previously Solar Probe, Solar Probe Plus or Solar Probe+) is a NASA space probe launched in 2018 with the mission of making observations of the outer corona of the Sun. It will approach to within 9.86 solar radii ...

, September 2018

References

{{reflist, 2 Telescopes Astronomical imaging