Tim Hawarden | |
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Born | Timothy George Hawarden 24 December 1943 Mossel Bay, Cape Province, South Africa |
Died | 10 November 2009 65) Edinburgh, Scotland | (aged
Alma mater |
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Known for | Passive cooling of space telescopes |
Spouse | Frances Shaw (m. 1983) |
Children | 2 |
Awards | NASA Exceptional Technology Achievement Medal (2010) |
Scientific career | |
Fields | Astrophysics |
Institutions | |
Thesis | Old Southern Open Clusters (1975) |
Doctoral advisor | Brian Warner |
Timothy George Hawarden FRAS (24 December 1943 – 10 November 2009) was a South African astrophysicist known for his pioneering work on passive cooling techniques for space telescopes for which he won NASA's Exceptional Technology Achievement Medal.
Hawarden was born in Mossel Bay, Cape Province, South Africa. He graduated from the University of Natal in 1966 with a BSc in Physics and Applied Mathematics, and then graduated from the University of Cape Town with an MSc in Astronomy 1970 and then a PhD in 1975 on old open clusters. [1] [2] While undertaking his PhD he worked as an optical astronomer at the Royal Observatory, Cape of Good Hope and then from 1972 as the Deputy Head of the Photometry Department at the South African Astronomical Observatory in Cape Town. [3] In 1975 he worked as the Deputy Astronomer-in-Charge of the UK Schmidt Telescope at the Siding Spring Observatory in New South Wales, Australia. [4]
In 1978 he moved to work at the Royal Observatory in Edinburgh, Scotland, from which he was based for the rest of his career. [5] In 1981 he began working on the United Kingdom Infrared Telescope in Hawaii. In 1987 he moved to Hawaii and led the telescope's ambitious upgrades programme throughout the 1990s. [6] [7] He returned to Edinburgh in 2001 and became the UK Astronomy Technology Centre Project Scientist developing extremely large telescopes (ELT) before retiring in 2006 to care for his wife Frances. [8] He remained active in the field of astronomy until his sudden death in Edinburgh in 2009. [3]
Hawarden was involved in the development of the Infrared Space Observatory as the Co-Investigator for the infrared camera (ISOCAM) but he considered the cryogenic cooling system "horrendously complicated". [9] [10] The dependency of infrared space telescopes on cryogenic cooling limited the telescope's lifespan as well as adding significant weight. In the early 1980s Hawarden began developing the idea of using passive cooling for infrared space telescopes through a combination of radiators, sunshields, and by locating the telescope further from Earth. [11] [12] Having a telescope orbit the Sun–Earth L2 Lagrange point enables the sunshield to shelter the telescope from the radiant heat of the Sun, the Earth, and the Moon. A passively cooled telescope is significantly lighter and permits much larger optics and instruments. [13]
In 1989 Hawarden proposed such a telescope, the Passively Cooled Orbiting Infrared Observatory Telescope (POIROT) to the European Space Agency but the design was rejected. [14] In 1991 Hawarden and Harley Thronson proposed a similar design to NASA for the Edison project but the proposal was also rejected. [15] [16] [17] The ideas continued to face resistance though some passive cooling was incorporated into the design of the 0.85 m (2.8 ft) diameter Spitzer Space Telescope launched in 2003. [11] The ideas were later adopted in full for the 6.5 m (21 ft) diameter James Webb Space Telescope launched in 2021. [18]
In 2010 Hawarden was posthumously awarded the NASA Exceptional Technology Achievement Medal for his work on passive cooling techniques, the award citing "the breakthrough concepts that made possible the James Webb Space Telescope and its successors". The award was accepted on behalf of Hawarden's widow Frances by the Nobel-laureate physicist John C. Mather. [12]
Infrared astronomy is a sub-discipline of astronomy which specializes in the observation and analysis of astronomical objects using infrared (IR) radiation. The wavelength of infrared light ranges from 0.75 to 300 micrometers, and falls in between visible radiation, which ranges from 380 to 750 nanometers, and submillimeter waves.
A galaxy cluster, or a cluster of galaxies, is a structure that consists of anywhere from hundreds to thousands of galaxies that are bound together by gravity, with typical masses ranging from 1014 to 1015 solar masses. They are the second-largest known gravitationally bound structures in the universe after some superclusters (of which only one, the Shapley Supercluster, is known to be bound). They were believed to be the largest known structures in the universe until the 1980s, when superclusters were discovered. One of the key features of clusters is the intracluster medium (ICM). The ICM consists of heated gas between the galaxies and has a peak temperature between 2–15 keV that is dependent on the total mass of the cluster. Galaxy clusters should not be confused with galactic clusters (also known as open clusters), which are star clusters within galaxies, or with globular clusters, which typically orbit galaxies. Small aggregates of galaxies are referred to as galaxy groups rather than clusters of galaxies. The galaxy groups and clusters can themselves cluster together to form superclusters.
The Infrared Astronomical Satellite (IRAS) was the first space telescope to perform a survey of the entire night sky at infrared wavelengths. Launched on 25 January 1983, its mission lasted ten months. The telescope was a joint project of the United States (NASA), the Netherlands (NIVR), and the United Kingdom (SERC). Over 250,000 infrared sources were observed at 12, 25, 60, and 100 micrometer wavelengths.
The Spitzer Space Telescope, formerly the Space Infrared Telescope Facility (SIRTF), is an infrared space telescope launched in 2003, that was deactivated when operations ended on 30 January 2020. Spitzer was the third space telescope dedicated to infrared astronomy, following IRAS (1983) and ISO (1995–1998). It was the first spacecraft to use an Earth-trailing orbit, later used by the Kepler planet-finder.
The James Webb Space Telescope (JWST) is a space telescope designed to conduct infrared astronomy. Its high-resolution and high-sensitivity instruments allow it to view objects too old, distant, or faint for the Hubble Space Telescope. This enables investigations across many fields of astronomy and cosmology, such as observation of the first stars and the formation of the first galaxies, and detailed atmospheric characterization of potentially habitable exoplanets.
NASA's series of Great Observatories satellites are four large, powerful space-based astronomical telescopes launched between 1990 and 2003. They were built with different technology to examine specific wavelength/energy regions of the electromagnetic spectrum: gamma rays, X-rays, visible and ultraviolet light, and infrared light.
The Near Infrared Camera and Multi-Object Spectrometer (NICMOS) is a scientific instrument for infrared astronomy, installed on the Hubble Space Telescope (HST), operating from 1997 to 1999, and from 2002 to 2008. Images produced by NICMOS contain data from the near-infrared part of the light spectrum.
The Herschel Space Observatory was a space observatory built and operated by the European Space Agency (ESA). It was active from 2009 to 2013, and was the largest infrared telescope ever launched until the launch of the James Webb Space Telescope in 2021. Herschel carries a 3.5-metre (11.5 ft) mirror and instruments sensitive to the far infrared and submillimetre wavebands (55–672 µm). Herschel was the fourth and final cornerstone mission in the Horizon 2000 programme, following SOHO/Cluster II, XMM-Newton and Rosetta.
Submillimetre astronomy or submillimeter astronomy is the branch of observational astronomy that is conducted at submillimetre wavelengths of the electromagnetic spectrum. Astronomers place the submillimetre waveband between the far-infrared and microwave wavebands, typically taken to be between a few hundred micrometres and a millimetre. It is still common in submillimetre astronomy to quote wavelengths in 'microns', the old name for micrometre.
A telescope is a device used to observe distant objects by their emission, absorption, or reflection of electromagnetic radiation. Originally it was an optical instrument using lenses, curved mirrors, or a combination of both to observe distant objects – an optical telescope. Nowadays, the word "telescope" is defined as wide range of instruments capable of detecting different regions of the electromagnetic spectrum, and in some cases other types of detectors.
Pillars of Creation is a photograph taken by the Hubble Space Telescope of elephant trunks of interstellar gas and dust in the Eagle Nebula, in the Serpens constellation, some 6,500–7,000 light-years from Earth. These elephant trunks had been discovered by John Charles Duncan in 1920 on a plate made with the Mount Wilson Observatory 60-inch telescope. They are named so because the gas and dust are in the process of creating new stars, while also being eroded by the light from nearby stars that have recently formed.
Frank James Low was a solid state physicist who became a leader in the new field of infrared astronomy, after inventing the gallium doped germanium bolometer in 1961. This detector extended the range of the observable spectrum to much longer wavelengths.
An infrared telescope is a telescope that uses infrared light to detect celestial bodies. Infrared light is one of several types of radiation present in the electromagnetic spectrum.
The James Webb Space Telescope (JWST) sunshield is a passive thermal control system deployed post-launch to shield the telescope and instrumentation from the light and heat of the Sun, Earth, and Moon. By keeping the telescope and instruments in permanent shadow, it allows them to cool to their design temperature of 40 kelvins. Its intricate deployment was successfully completed on January 4, 2022, ten days after launch, when it was more than 0.8 million kilometers (500,000 mi) away from Earth.
The Atmospheric Remote-sensing Infrared Exoplanet Large-survey (ARIEL) is a space telescope and the fourth medium-class mission of the European Space Agency's Cosmic Vision programme. The mission is aimed at observing at least 1000 known exoplanets using the transit method, studying and characterising the planets' chemical composition and thermal structures. Compared to the James Webb Space Telescope, ARIEL will be a much smaller telescope and have more observing time available for planet characterisation. ARIEL is expected to be launched in 2029 aboard an Arianespace Ariane 6 together with the Comet Interceptor.
Gillian Susan Wright is a Scottish astronomer who is currently the director of the UK Astronomy Technology Centre in Edinburgh, UK. She has also been involved in the development and construction of the James Webb Space Telescope as the European Principal Investigator for the Mid-Infrared Instrument (MIRI). In 2006 Wright was appointed MBE for services to science.
Webb's First Deep Field is the first operational image taken by the James Webb Space Telescope (JWST). The deep-field photograph, which covers a tiny area of sky visible from the Southern Hemisphere, is centered on SMACS 0723, a galaxy cluster in the constellation of Volans. Thousands of galaxies are visible in the image, some as old as 13 billion years. The image is the highest-resolution image of the early universe ever taken. Captured by the telescope's Near-Infrared Camera (NIRCam), the image was revealed to the public by NASA on 11 July 2022.
SMACS J0723.3–7327, commonly referred to as SMACS 0723, is a galaxy cluster about 4 billion light years from Earth, within the southern constellation of Volans. It is a patch of sky visible from the Southern Hemisphere on Earth and often observed by the Hubble Space Telescope and other telescopes in search of the deep past. It was the target of the first full-color image to be unveiled by the James Webb Space Telescope (JWST), imaged using NIRCam, with spectra included, showing objects lensed by the cluster with redshifts implying they are 13.1 billion years old. The cluster has been previously observed by the Hubble Space Telescope (HST) as part of the Southern MAssive Cluster Survey (SMACS), as well as Planck and Chandra.
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