Jump to content

IRAS

From Wikipedia, the free encyclopedia

This is an old revision of this page, as edited by Dutchsatellites.com (talk | contribs) at 11:07, 10 June 2008 (Edit infobox Space Telescope). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.

Infrared Astronomical Satellite (IRAS)
IRAS beside some of its all-sky images
COSPAR ID1983-004A Edit this at Wikidata
SATCAT no.13777Edit this on Wikidata
WebsiteIRAS website
Start of mission
Launch date25 January 1983

The Infrared Astronomical Satellite (IRAS) was the first-ever space-based observatory to perform a survey of the entire sky at infrared wavelengths.

Launched on January 25, 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).

IRAS was the first observatory to perform an all-sky survey at infrared wavelengths. It mapped 96% of the sky four times, at 12, 25, 60 and 100 micrometre wavelengths, with resolutions ranging from 30 arcseconds at wavelength 12 micrometers to 2 arcminutes at wavelength 100 micrometers. It discovered about 350,000 sources, many of which are still awaiting identification. About 75,000 of those are believed to be starburst galaxies, still enduring their star-formation stage. Many other sources are normal stars with disks of dust around them, possibly the early stage of a planetary system formation. New discoveries included a dust disk around Vega and the first images of the Milky Way Galaxy's core. The observatory also made headlines briefly with the discovery of an "unknown object" that was at first described as "possibly as large as the giant planet Jupiter and possibly so close to Earth that it would be part of this solar system."[1][2] However, further analysis revealed that, of several unidentified objects, nine were distant galaxies and the tenth was "intergalactic cirrus".[3] None were found to be Solar System bodies.[3]

IRAS's life, like most of infrared satellites that followed after IRAS, was limited by its cooling system: to effectively work in the infrared domain, the telescope must be cooled to impressively low temperatures. In IRAS' case, 475 liters of superfluid helium kept the telescope at a temperature of 2 kelvins (about −271 °C), keeping the satellite cool by evaporation. The on-board supply of fluid helium depleted after 10 months on November 22 1983, causing the telescope temperature to rise, preventing further observations.

IRAS was designed to catalogue fixed sources, so it scanned the same region of sky several times. Jack Meadows led a team at Leicester University, including John Davies and Simon Green, which searched the rejected sources for moving objects. This led to the discovery of three asteroids, including 3200 Phaethon (an Apollo asteroid and the parent body of the Geminid meteor shower), six comets, and a huge dust trail associated with comet Tempel-2. The comets included the periodic comets 126P/IRAS and 161P/Hartley-IRAS and comet IRAS-Araki-Alcock (C/1983 H1), which made a close approach to the Earth in 1983.

Several space infrared telescopes have continued and greatly expanded the study of the infrared Universe, such as the Infrared Space Observatory launched in 1995, the Spitzer Space Telescope launched in 2003, and the AKARI Space Telescope launched in 2006.

Asteroids discovered: 3
3200 Phaethon October 11 1983
3728 IRAS August 23 1983
(10714) 1983 QG August 31 1983

References

  1. ^ Thomas O'Toole (30 December 1983). "Mystery Heavenly Body Discovered". Washington Post. p. A1. Retrieved 2008-01-28. {{cite news}}: Check date values in: |date= (help); Unknown parameter |publisherlink= ignored (help)
  2. ^ Thomas O'Toole (30 December 1983). "Mystery Heavenly Body Discovered". Washington Post. p. A1. Retrieved 2008-01-28. {{cite news}}: Check date values in: |date= (help); Unknown parameter |publisherlink= ignored (help)
  3. ^ a b Thomas J. Chester. "No Tenth Planet Yet From IRAS". Thomas J. Chester (CalTech). Retrieved 2008-01-28.

See also

Retrieved from "https://en.wikipedia.org/enwiki/w/index.php?title=IRAS&oldid=218376633"