Ultraviolet astronomy

Source: Wikipedia, the free encyclopedia.
Caltech
.

Ultraviolet astronomy is the observation of electromagnetic radiation at ultraviolet wavelengths between approximately 10 and 320 nanometres; shorter wavelengths—higher energy photons—are studied by X-ray astronomy and gamma-ray astronomy.[1] Ultraviolet light is not visible to the human eye.[2] Most of the light at these wavelengths is absorbed by the Earth's atmosphere, so observations at these wavelengths must be performed from the upper atmosphere or from space.[1]

Overview

Ultraviolet line spectrum measurements (spectroscopy) are used to discern the chemical composition, densities, and temperatures of the interstellar medium, and the temperature and composition of hot young stars. UV observations can also provide essential information about the evolution of galaxies. They can be used to discern the presence of a hot white dwarf or main sequence companion in orbit around a cooler star.[3][4]

The ultraviolet

visible light
. Most stars are actually relatively cool objects emitting much of their electromagnetic radiation in the visible or near-infrared part of the spectrum. Ultraviolet radiation is the signature of hotter objects, typically in the early and late stages of their evolution. In the Earth's sky seen in ultraviolet light, most stars would fade in prominence. Some very young massive stars and some very old stars and galaxies, growing hotter and producing higher-energy radiation near their birth or death, would be visible. Clouds of gas and dust would block the vision in many directions along the Milky Way.

Space-based solar observatories such as

corona. Weather satellites such as the GOES-R series also carry telescopes
for observing the Sun in ultraviolet.

The

.

Pioneers in ultraviolet astronomy include George Robert Carruthers, Robert Wilson, and Charles Stuart Bowyer.

high-energy X-ray
and ultraviolet light (released 5 January 2016).

Ultraviolet space telescopes

Astro 2 UIT captures M101 with ultraviolet shown in purple

See also List of ultraviolet space telescopes

Ultraviolet instruments on planetary spacecraft

  • United States - UVIS (Cassini) - 1997 (at Saturn from 2004 to 2017)
  • United States - MASCS (MESSENGER) - 2004 (at Mercury from 2011 to 2015)
  • United States - Alice (New Horizons) - 2006 (Pluto flyby in 2015)
  • United States - UVS (Juno) - 2011 (at Jupiter since 2016)
  • United States - IUVS (MAVEN) - 2013 (at Mars since 2014)

See also

  • Markarian galaxies – Galaxy with a nucleus emitting exceptionally large amounts of ultraviolet
  • Pea galaxy – Possible type of luminous blue compact galaxy

References

External links