Astronomical survey

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Composite image of the GOODS-South field, result of a deep survey using two of the four giant 8.2-metre telescopes composing ESO's Very Large Telescope GOODS-South field.jpg
Composite image of the GOODS-South field, result of a deep survey using two of the four giant 8.2-metre telescopes composing ESO's Very Large Telescope
Gamma-ray pulsars detected by the Fermi Gamma-ray Space Telescope Fermi's Gamma-ray Pulsars.jpg
Gamma-ray pulsars detected by the Fermi Gamma-ray Space Telescope

An astronomical survey is a general map or image of a region of the sky (or of the whole sky) that lacks a specific observational target. Alternatively, an astronomical survey may comprise a set of images, spectra, or other observations of objects that share a common type or feature. Surveys are often restricted to one band of the electromagnetic spectrum due to instrumental limitations, although multiwavelength surveys can be made by using multiple detectors, each sensitive to a different bandwidth. [1]

Contents

Surveys have generally been performed as part of the production of an astronomical catalog. They may also search for transient astronomical events. They often use wide-field astrographs.

Scientific value

Sky surveys, unlike targeted observation of a specific object, allow astronomers to catalog celestial objects and perform statistical analyses on them without complex corrections for selection effects. In some cases, an astronomer interested in a particular object will find that survey images are sufficient to make new telescope time entirely unnecessary.

Surveys also help astronomers choose targets for closer study using larger, more powerful telescopes. If previous observations support a hypothesis, a telescope scheduling committee is more likely to approve new, more detailed observations to test it.

The wide scope of surveys makes them ideal for finding foreground objects that move, such as asteroids and comets. An astronomer can compare existing survey images to current observations to identify changes; this task can even be performed automatically using image analysis software. Besides science, these surveys also detect potentially hazardous objects. Similarly, images of the same object taken by different surveys can be compared to detect transient astronomical events such as variable stars. [2]

List of sky surveys

Spectrum of types of observations of Solar System objects. Uncertain size-frequency distribution of interstellar visitors.jpg
Spectrum of types of observations of Solar System objects.
The positions in space of just some of the galaxies identified by the VIPERS survey (see Visible Multi Object Spectrograph). A large slice of the Universe.jpg
The positions in space of just some of the galaxies identified by the VIPERS survey (see Visible Multi Object Spectrograph).

Surveys of the Magellanic Clouds

See also

Related Research Articles

<span class="mw-page-title-main">Very Large Telescope</span> Telescope in the Atacama Desert, Chile

The Very Large Telescope (VLT) is a facility operated by the European Southern Observatory, located on Cerro Paranal in the Atacama Desert of northern Chile. It consists of four individual telescopes, each equipped with a primary mirror that measures 8.2 meters in diameter. These optical telescopes, named Antu, Kueyen, Melipal, and Yepun, are generally used separately but can be combined to achieve a very high angular resolution. The VLT array is also complemented by four movable Auxiliary Telescopes (ATs) with 1.8-meter apertures.

<span class="mw-page-title-main">European Southern Observatory</span> Intergovernmental organization and observatory in Chile

The European Organisation for Astronomical Research in the Southern Hemisphere, commonly referred to as the European Southern Observatory (ESO), is an intergovernmental research organisation made up of 16 member states for ground-based astronomy. Created in 1962, ESO has provided astronomers with state-of-the-art research facilities and access to the southern sky. The organisation employs over 750 staff members and receives annual member state contributions of approximately €162 million. Its observatories are located in northern Chile.

<span class="mw-page-title-main">Hubble Deep Field</span> Multiple exposure image of deep space in the constellation Ursa Major

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<span class="mw-page-title-main">Observational astronomy</span> Division of astronomy

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<span class="mw-page-title-main">Australian Astronomical Observatory</span> Observatory

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<span class="mw-page-title-main">VLT Survey Telescope</span> Telescope in the Atacama Desert, Chile

The VLT Survey Telescope (VST) is a telescope located at ESO's Paranal Observatory in the Atacama Desert of northern Chile. It is housed in an enclosure immediately adjacent to the four Very Large Telescope (VLT) Unit Telescopes on the summit of Cerro Paranal. The VST is a wide-field survey telescope with a field of view twice as broad as the full Moon. It is the largest telescope in the world designed to exclusively survey the sky in visible light.

<span class="mw-page-title-main">VISTA (telescope)</span>

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<span class="mw-page-title-main">Redshift survey</span>

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<span class="mw-page-title-main">Multi-unit spectroscopic explorer</span> Integral field spectrograph installed at the Very Large Telescope

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<span class="mw-page-title-main">Hubble Deep Field South</span>

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<span class="mw-page-title-main">Astronomical interferometer</span> Array used for astronomical observations

An astronomical interferometer or telescope array is a set of separate telescopes, mirror segments, or radio telescope antennas that work together as a single telescope to provide higher resolution images of astronomical objects such as stars, nebulas and galaxies by means of interferometry. The advantage of this technique is that it can theoretically produce images with the angular resolution of a huge telescope with an aperture equal to the separation, called baseline, between the component telescopes. The main drawback is that it does not collect as much light as the complete instrument's mirror. Thus it is mainly useful for fine resolution of more luminous astronomical objects, such as close binary stars. Another drawback is that the maximum angular size of a detectable emission source is limited by the minimum gap between detectors in the collector array.

<span class="mw-page-title-main">Leibniz Institute for Astrophysics Potsdam</span> Research facility for astrophysics

Leibniz Institute for Astrophysics Potsdam (AIP) is a German research institute. It is the successor of the Berlin Observatory founded in 1700 and of the Astrophysical Observatory Potsdam (AOP) founded in 1874. The latter was the world's first observatory to emphasize explicitly the research area of astrophysics. The AIP was founded in 1992, in a re-structuring following the German reunification.

<span class="mw-page-title-main">Great Observatories Origins Deep Survey</span> Astronomical survey that combines observations from 3 great NASA observatories

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, along with data from other space-based telescopes, such as XMM Newton, and some of the world's most powerful ground-based telescopes.

<span class="mw-page-title-main">GRB 090423</span> Gamma-ray burst detected in 2009

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<span class="mw-page-title-main">Integral field spectrograph</span> Spectrograph equipped with an integral field unit

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The Palomar Transient Factory, was an astronomical survey using a wide-field survey camera designed to search for optical transient and variable sources such as variable stars, supernovae, asteroids and comets. The project completed commissioning in summer 2009, and continued until December 2012. It has since been succeeded by the Intermediate Palomar Transient Factory (iPTF), which itself transitioned to the Zwicky Transient Facility in 2017/18. All three surveys are registered at the MPC under the same observatory code for their astrometric observations.

<i>Euclid</i> (spacecraft) European visible and near-infrared space observatory

Euclid is a wide-angle space telescope with a 600-megapixel camera to record visible light, a near-infrared spectrometer, and photometer, to determine the redshift of detected galaxies. It was developed by the European Space Agency (ESA) and the Euclid Consortium and was launched on 1 July 2023.

References

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