WISE eyes on the skies

via Discovery News.

The Wide field Infrared Survey Explorer is a satellite designed to map the entire night sky in infrared light. Survey telescopes are often employed to give a big picture – show where things of interest lie at any given time. They need wide angled images of the sky, as opposed to the smaller fields used during examinations of individual astronomical objects. Several surveys have translated their results into catalogues of night sky objects. Galaxy Zoo is fed from the Sloan Digital Sky survey.

WISE will follow in the footsteps of IRAS, the Infra Red Astronomical Satellite, which ran in the 80’s. WISE has 500 times the resolving power of IRAS and will be able to provide a much sharper view of the infrared sky over the ten months of science operations.

Three objects of particular interest are asteroids, brown dwarfs and ultraluminous galaxies. The ultraluminous galaxies are very distant galaxies undergoing rapid star formation. Star formation is accompanied by a lot of infrared emission, making WISE ideal for pinpointing these things. Brown dwarfs are objects intermediate between a gas giant planet and a star. Capable of slowly fusing deuterium (heavy hydrogen) into helium, they glow dimly and mostly in infrared. Asteroids similarly glow dimly, warmed by the heat of the Sun, they emit most brightly at their black body temperature – the equilibrium temperature of an object absorbing and emitting radiation. For asteroids, this leaves them relatively bright in the infrared and darker asteroids absorbing more light, will glow more brightly. In visible light, their brightness depends both on distance from the Sun and how reflective their surface is, getting information in both wavelengths will narrow down the possible ranges of diameters for the objects (those that aren’t directly measurable). It is expected an extra hundred or so asteroids will be discovered and several more detected but without enough data to be officially ‘discovered’.


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