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Team of astronomers discovers galaxy that shouldn't exist

A team of astronomers, led by Arizona State University Assistant Research Scientist Tim Carleton, has discovered a dwarf galaxy that appeared in James Webb Space Telescope imaging that wasn't the primary observation target.

Image: Hubble views a massive star forming

This image from the NASA/ESA Hubble Space Telescope is teeming with color and activity. It features a relatively close star-forming region known as IRAS 16562-3959, which lies within the Milky Way about 5,900 light-years ...

Betelgeuse before, during and after the Great Dimming

When a prominent star in the night sky suddenly dims, it generates a lot of interest. That's what happened with the red supergiant star Betelgeuse between November 2019 and May 2020. Betelgeuse will eventually explode as ...

Image: Hubble captures globular cluster NGC 2298

This new NASA Hubble Space Telescope view shows the globular cluster NGC 2298, a sparkling collection of thousands of stars held together by their mutual gravitational attraction. Globular clusters are typically home to older ...

Wavelength

In physics, the wavelength of a sinusoidal wave is the spatial period of the wave – the distance over which the wave's shape repeats. It is usually determined by considering the distance between consecutive corresponding points of the same phase, such as crests, troughs, or zero crossings, and is a characteristic of both traveling waves and standing waves. Wavelength is commonly designated by the Greek letter lambda (λ). The concept can also be applied to periodic waves of non-sinusoidal shape. The term wavelength is also sometimes applied to modulated waves, and to the sinusoidal envelopes of modulated waves or waves formed by interference of several sinusoids.

Assuming a sinusoidal wave moving at a fixed wave speed, wavelength is inversely proportional to frequency: waves with higher frequencies have shorter wavelengths, and lower frequencies have longer wavelengths.

Examples of wave-like phenomena are sound waves, light, and water waves. A sound wave is a periodic variation in air pressure, while in light and other electromagnetic radiation the strength of the electric and the magnetic field vary. Water waves are periodic variations in the height of a body of water. In a crystal lattice vibration, atomic positions vary periodically in both lattice position and time.

Wavelength is a measure of the distance between repetitions of a shape feature such as peaks, valleys, or zero-crossings, not a measure of how far any given particle moves. For example, in waves over deep water a particle in the water moves in a circle of the same diameter as the wave height, unrelated to wavelength.

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