Absorption spectrum observed by Hubble space telescope
The absorption spectrum of a material shows the fraction of electromagnetic radiation absorbed in a certain range of frequencies. It is, in a sense, the opposite of the emission spectrum. Each chemical element has its own absorption lines corresponding to specific wavelengths and the differences between the energy levels of its atomic orbitals. For example, an object that absorbs blue, green, and yellow would look red if lit by a white light. For this reason the absorption spectrum can be used to identify elements present in a gas or liquid. This method is applied to deduct elements in stars and other gaseous objects that can not be measured directly. Voices correlateemodify wikitesto
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