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37-650: [REDACTED] Look up astronomer in Wiktionary, the free dictionary. The Astronomer may refer to: Vita Hludovici or the "Limousin Astronomer", the anonymous author of the Vita Hludovici, a biography of Holy Roman Emperor Louis the Pious The Astronomer (Vermeer) , a 1668 oil painting by the 17th century Dutch painter Johannes Vermeer The Astronomer ,

74-545: A character in the Wild Cards book series Topics referred to by the same term [REDACTED] This disambiguation page lists articles associated with the title The Astronomer . If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=The_Astronomer&oldid=1179086068 " Category : Disambiguation pages Hidden categories: Short description

111-421: A few dedicated infrared telescopes, need to be chilled with liquid nitrogen and shielded from warm objects. The reason for this is that objects with temperatures of a few hundred kelvins emit most of their thermal energy at infrared wavelengths. If infrared detectors were not kept cooled, the radiation from the detector itself would contribute noise that would dwarf the radiation from any celestial source. This

148-427: A few hours a month to stargazing and reading the latest developments in research. However, amateurs span the range from so-called "armchair astronomers" to the highly ambitious people who own science-grade telescopes and instruments with which they are able to make their own discoveries, create astrophotographs , and assist professional astronomers in research. Infrared astronomy Infrared astronomy began in

185-438: A few weeks per year. Analysis of observed phenomena, along with making predictions as to the causes of what they observe, takes the majority of observational astronomers' time. Astronomers who serve as faculty spend much of their time teaching undergraduate and graduate classes. Most universities also have outreach programs, including public telescope time and sometimes planetariums , as a public service to encourage interest in

222-547: A group of international infrared astronomers proved that intergalactic dust greatly dims the light of distant galaxies. In actuality, galaxies are almost twice as bright as they look. The dust absorbs much of the visible light and re-emits it as infrared light. Infrared radiation with wavelengths just longer than visible light, known as near-infrared, behaves in a very similar way to visible light, and can be detected using similar solid state devices (because of this, many quasars, stars, and galaxies were discovered). For this reason,

259-660: Is absorbed at many wavelengths by water vapor in the Earth's atmosphere , so most infrared telescopes are at high elevations in dry places, above as much of the atmosphere as possible. There have also been infrared observatories in space , including the Spitzer Space Telescope , the Herschel Space Observatory , and more recently the James Webb Space Telescope . The discovery of infrared radiation

296-439: Is a submillimeter satellite. For many space telescopes, only some of the instruments are capable of infrared observation. Below are listed some of the most notable of these space observatories and instruments: Three airplane-based observatories have been used (other aircraft have also been used occasionally to host infrared space studies) to study the sky in infrared. They are: Many ground-based infrared telescopes exist around

333-402: Is attributed to William Herschel, who performed an experiment in 1800 where he placed a thermometer in sunlight of different colors after it passed through a prism . He noticed that the temperature increase induced by sunlight was highest outside the visible spectrum, just beyond the red color. That the temperature increase was highest at infrared wavelengths was due to the spectral response of

370-409: Is consistent with the modern value, so George Rieke gives Nichols credit for the first detection of a star other than our own in the infrared. The field of infrared astronomy continued to develop slowly in the early 20th century, as Seth Barnes Nicholson and Edison Pettit developed thermopile detectors capable of accurate infrared photometry and sensitive to a few hundreds of stars. The field

407-403: Is different from Wikidata All article disambiguation pages All disambiguation pages astronomer An astronomer is a scientist in the field of astronomy who focuses on a specific question or field outside the scope of Earth . Astronomers observe astronomical objects , such as stars , planets , moons , comets and galaxies – in either observational (by analyzing

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444-465: Is often achieved by a coolant, which can run out. Space missions have either ended or shifted to "warm" observations when the coolant supply used up. For example, WISE ran out of coolant in October 2010, about ten months after being launched. (See also NICMOS , Spitzer Space Telescope) Many space telescopes detect electromagnetic radiation in a wavelength range that overlaps at least to some degree with

481-475: Is particularly important in the mid-infrared and far-infrared regions of the spectrum. To achieve higher angular resolution , some infrared telescopes are combined to form astronomical interferometers . The effective resolution of an interferometer is set by the distance between the telescopes, rather than the size of the individual telescopes. When used together with adaptive optics , infrared interferometers, such as two 10 meter telescopes at Keck Observatory or

518-450: Is transparent. The main infrared windows are listed below: As is the case for visible light telescopes, space is the ideal place for infrared telescopes. Telescopes in space can achieve higher resolution, as they do not suffer from blurring caused by the Earth's atmosphere, and are also free from infrared absorption caused by the Earth's atmosphere. Current infrared telescopes in space include

555-421: Is utilized by astronomers to study the universe . Indeed, infrared measurements taken by the 2MASS and WISE astronomical surveys have been particularly effective at unveiling previously undiscovered star clusters . Examples of such embedded star clusters are FSR 1424, FSR 1432, Camargo 394, Camargo 399, Majaess 30, and Majaess 99. Infrared telescopes, which includes most major optical telescopes as well as

592-633: The Double Helix Nebula , and light from extrasolar planets . It continued working in 3.6 and 4.5 micrometer bands. Since then, other infrared telescopes helped find new stars that are forming, nebulae, and stellar nurseries. Infrared telescopes have opened up a whole new part of the galaxy for us. They are also useful for observing extremely distant things, like quasars . Quasars move away from Earth. The resulting large redshift make them difficult targets with an optical telescope. Infrared telescopes give much more information about them. During May 2008,

629-635: The Herschel Space Observatory , the Spitzer Space Telescope , the Wide-field Infrared Survey Explorer and the James Webb Space Telescope . Since putting telescopes in orbit is expensive, there are also airborne observatories , such as the Stratospheric Observatory for Infrared Astronomy and the Kuiper Airborne Observatory . These observatories fly above most, but not all, of the atmosphere, and water vapor in

666-705: The Nancy Grace Roman Space Telescope (NGRST), originally known as the Wide Field InfraRed Space Telescope (WFIRST), in 2027. Many other smaller space-missions and space-based detectors of infrared radiation have been operated in space. These include the Infrared Telescope (IRT) that flew with the Space Shuttle . The Submillimeter Wave Astronomy Satellite (SWAS) is sometimes mentioned as an infrared satellite, although it

703-465: The 1830s, a few decades after the discovery of infrared light by William Herschel in 1800. Early progress was limited, and it was not until the early 20th century that conclusive detections of astronomical objects other than the Sun and Moon were made in infrared light. After a number of discoveries were made in the 1950s and 1960s in radio astronomy , astronomers realized the information available outside

740-658: The European Space Agency created the Infrared Space Observatory . Before this satellite ran out of liquid helium in 1998, it discovered protostars and water in our universe (even on Saturn and Uranus). On 25 August 2003, NASA launched the Spitzer Space Telescope , previously known as the Space Infrared Telescope Facility. In 2009, the telescope ran out of liquid helium and lost the ability to see far infrared . It had discovered stars,

777-516: The Moon was first detected in 1856 by Charles Piazzi Smyth , the Astronomer Royal for Scotland, during an expedition to Tenerife to test his ideas about mountain top astronomy. Ernest Fox Nichols used a modified Crookes radiometer in an attempt to detect infrared radiation from Arcturus and Vega , but Nichols deemed the results inconclusive. Even so, the ratio of flux he reported for the two stars

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814-542: The PhD level and beyond (as of 2024). Contrary to the classical image of an old astronomer peering through a telescope through the dark hours of the night, it is far more common to use a charge-coupled device (CCD) camera to record a long, deep exposure, allowing a more sensitive image to be created because the light is added over time. Before CCDs, photographic plates were a common method of observation. Modern astronomers spend relatively little time at telescopes, usually just

851-662: The atmosphere absorbs some of infrared light from space. One of the most common infrared detector arrays used at research telescopes is HgCdTe arrays. These operate well between 0.6 and 5 micrometre wavelengths. For longer wavelength observations or higher sensitivity other detectors may be used, including other narrow gap semiconductor detectors, low temperature bolometer arrays or photon-counting Superconducting Tunnel Junction arrays. Special requirements for infrared astronomy include: very low dark currents to allow long integration times, associated low noise readout circuits and sometimes very high pixel counts. Low temperature

888-421: The core sciences, a competency examination, experience with teaching undergraduates and participating in outreach programs, work on research projects under the student's supervising professor, completion of a PhD thesis , and passing a final oral exam . Throughout the PhD training, a successful student is financially supported with a stipend . While there is a relatively low number of professional astronomers,

925-531: The data) or theoretical astronomy . Examples of topics or fields astronomers study include planetary science , solar astronomy , the origin or evolution of stars , or the formation of galaxies . A related but distinct subject is physical cosmology , which studies the Universe as a whole. Astronomers usually fall under either of two main types: observational and theoretical . Observational astronomers make direct observations of celestial objects and analyze

962-903: The data. In contrast, theoretical astronomers create and investigate models of things that cannot be observed. Because it takes millions to billions of years for a system of stars or a galaxy to complete a life cycle, astronomers must observe snapshots of different systems at unique points in their evolution to determine how they form, evolve, and die. They use this data to create models or simulations to theorize how different celestial objects work. Further subcategories under these two main branches of astronomy include planetary astronomy , astrobiology , stellar astronomy , astrometry , galactic astronomy , extragalactic astronomy , or physical cosmology . Astronomers can also specialize in certain specialties of observational astronomy, such as infrared astronomy , neutrino astronomy , x-ray astronomy , and gravitational-wave astronomy . Historically , astronomy

999-469: The field is popular among amateurs . Most cities have amateur astronomy clubs that meet on a regular basis and often host star parties . The Astronomical Society of the Pacific is the largest general astronomical society in the world, comprising both professional and amateur astronomers as well as educators from 70 different nations. As with any hobby , most people who practice amateur astronomy may devote

1036-489: The field. Those who become astronomers usually have a broad background in physics, mathematics , sciences, and computing in high school. Taking courses that teach how to research, write, and present papers are part of the higher education of an astronomer, while most astronomers attain both a Master's degree and eventually a PhD degree in astronomy, physics or astrophysics . PhD training typically involves 5-6 years of study, including completion of upper-level courses in

1073-547: The four 8.2 meter telescopes that make up the Very Large Telescope Interferometer, can achieve high angular resolution. The principal limitation on infrared sensitivity from ground-based telescopes is the Earth's atmosphere. Water vapor absorbs a significant amount of infrared radiation, and the atmosphere itself emits at infrared wavelengths. For this reason, most infrared telescopes are built in very dry places at high altitude, so that they are above most of

1110-425: The infrared wavelength range. Therefore it is difficult to define which space telescopes are infrared telescopes. Here the definition of "infrared space telescope" is taken to be a space telescope whose main mission is detecting infrared light. Eight infrared space telescopes have been operated in space. They are: In addition, SPHEREx is a telescope scheduled for launch in 2025. NASA is also planning to launch

1147-687: The majority of their time working on research, although they quite often have other duties such as teaching, building instruments, or aiding in the operation of an observatory. The American Astronomical Society , which is the major organization of professional astronomers in North America , has approximately 8,200 members (as of 2024). This number includes scientists from other fields such as physics, geology , and engineering , whose research interests are closely related to astronomy. The International Astronomical Union comprises about 12,700 members from 92 countries who are involved in astronomical research at

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1184-570: The near infrared region of the spectrum is commonly incorporated as part of the "optical" spectrum, along with the near ultraviolet. Many optical telescopes , such as those at Keck Observatory , operate effectively in the near infrared as well as at visible wavelengths. The far-infrared extends to submillimeter wavelengths , which are observed by telescopes such as the James Clerk Maxwell Telescope at Mauna Kea Observatory . Like all other forms of electromagnetic radiation , infrared

1221-529: The prism rather than properties of the Sun, but the fact that there was any temperature increase at all prompted Herschel to deduce that there was invisible radiation from the Sun. He dubbed this radiation "calorific rays", and went on to show that it could be reflected, transmitted, and absorbed just like visible light. Efforts were made starting in the 1830s and continuing through the 19th century to detect infrared radiation from other astronomical sources. Radiation from

1258-426: The visible wavelength range, and modern infrared astronomy was established. Infrared and optical astronomy are often practiced using the same telescopes , as the same mirrors or lenses are usually effective over a wavelength range that includes both visible and infrared light. Both fields also use solid state detectors, though the specific type of solid state photodetectors used are different. Infrared light

1295-562: The water vapor in the atmosphere. Suitable locations on Earth include Mauna Kea Observatory at 4205 meters above sea level, the Paranal Observatory at 2635 meters in Chile and regions of high altitude ice-desert such as Dome C in Antarctic . Even at high altitudes, the transparency of the Earth's atmosphere is limited except in infrared windows , or wavelengths where the Earth's atmosphere

1332-498: Was more concerned with the classification and description of phenomena in the sky, while astrophysics attempted to explain these phenomena and the differences between them using physical laws . Today, that distinction has mostly disappeared and the terms "astronomer" and "astrophysicist" are interchangeable. Professional astronomers are highly educated individuals who typically have a PhD in physics or astronomy and are employed by research institutions or universities. They spend

1369-500: Was mostly neglected by traditional astronomers until the 1960s, with most scientists who practiced infrared astronomy having actually been trained physicists . The success of radio astronomy during the 1950s and 1960s, combined with the improvement of infrared detector technology, prompted more astronomers to take notice, and infrared astronomy became well established as a subfield of astronomy. Infrared space telescopes entered service. In 1983, IRAS made an all-sky survey. In 1995,

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