Uranus Through the Telescope

For most telescopic observers, Uranus presents a somewhat disappointing sight. All that can normally be seen is a small, pale blue-green disk showing no detail. Larger telescopes will reveal its five brightest moons, which are (in order of descending opposition magnitude) Titania (magnitude +13.7), Oberon (mag. +13.9), Ariel (mag. +14.2), Umbriel (mag. +14.8) and Miranda (mag. +16.3). For useful observation of the planet, telescopes of at least 8 inches (200mm) aperture and magnifications of 300x or more are generally considered necessary.

Even through large telescopes the planet often appears fuzzy and indistinct. Brightness variations are sometimes reported, the likely result of changes in the planet's atmosphere. In particular, observers have reported a light banding across the planet's equatorial region (whenever this is on view - of which, see below). Overall, Uranus will appear to brighten slightly at each successive opposition through to its perihelion in 2050.

Because of Uranus' unusual axial tilt (98° relative to the plane of its orbit) it presents very different aspects when seen from the Earth. In the course of its 84-year orbit around the Sun, it variously appears pole-on to the Earth, sideways-on, or somewhere in-between. Its equator was last seen face-on to the Earth in December 2007; its South Pole will appear face-on to the Earth in 2030.

When mounted on a tripod, digital cameras fitted with a zoom lens will easily detect the planet at shutter speeds of only a couple of seconds at higher ISO (film speed) settings. Some photos will even reveal the characteristic colouration of the planet.

The images of the planet seen here were taken using a DSLR camera pointed through the eyepiece of an 8-inch reflecting telescope in 2006. The rippling effect simulates how the Earth's turbulent atmosphere (the 'seeing conditions') affects the steadiness and clarity of the telescopic image.

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