Original caption: "Delta-Doped Charged Coupled Devices

Delta-Doped Charged Coupled Devices (CCD) for Ultra-Violet and Visible Detection

CCDs allow scientists to study one of the least explored windows of the electromagnetic spectrum - the extreme ultraviolet. Until recently, scientists believed there was little point to exploring this spectral region. They thought that the mixture of hydrogen gas and other less abundant gases, which fill the space between stars and is commonly called the "interstellar medium," would absorb virtually all extreme ultraviolet radiation before it became detectable from Earth. Consequently, this region became known as the "unobservable ultraviolet."

This is where stable ultraviolet CCDs step in for crucial space and ground-based astronomy to detect younger, hotter objects. Because of the high quantum efficiency of these devices, very faint objects can potentially be observed. Stability of the device makes it possible to gather reliable data in space-based astronomy.

Scientists will learn much more about hot white dwarf stars - extremely dense stars that represent a final stage of stellar evolution - and young massive stars that are characterized by outflowing, shock-heated winds. Moreover, they will learn about cataclysmic variable stars, binary star systems in which the mass of one star is transferred to the other, causing dramatic changes in extreme ultraviolet brightness. They may even have a chance to probe the enigmatic cores of distant galaxies."

Taken from:[1] copie d'archive sur Wayback Machine

	Ce fichier provient de la NASA. Sauf exception, les documents créés par la NASA ne sont pas soumis à copyright. Pour plus d'informations, voir la politique de copyright de la NASA.
	Attention : Les documents provenant du téléscope Hubble sont soumis à copyright s'ils ne sont pas crédités à STScI. Voir les détails. Les documents créés par la sonde SOHO sont soumis à copyright et requièrent une permission pour un usage commercial et/ou non-éducatif. Voir les détails. Les images issues du site web Astronomy Picture of the Day (APOD) sont soumises à copyright. Voir les détails.