A star is a aster like the Sun, it shines through nuclear reactions that occur in the center. In our Milky Way, he was born an average of four or five stars each year.
The star-forming young stars are often called.
Molecular clouds are composed of interstellar dust wandering, left during the formation of the galaxy.
The main mater of interstellar clouds, is hydrogen, is the main constituent of stars. All the stars are considerably farther from Earth than the Sun. The nearest star, Proxima Centauri, is located about 4 light years of the solar system, nearly 250 000 times further away than the Sun. European Herschel space telescope has produced a beautiful image of the star Fomalhaut. This young star in the constellation of the Southern Fish is surrounded by a disk of interplanetary dust, visible on the infrared image.
The Herschel space telescope in orbit 1.5 million km from Earth, observed the star Fomalhaut in the wavelengths of the infrared between 780 nm and 1000 microns. This young blue star, located only 25.1 light-year is younger than 250 million years. It is eighteen times more luminous than our star, the Sun. The image of the Solar System Fomalhaut was taken at 850 microns wavelength by Alma.
This image of unprecedented accuracy is within a wavelength greater, it shows much more detail of the protoplanetary disk. As the star Fomalhaut is very young (250 million years), we still see no planets orbit in the ring around the star. Moreover, this ring is more like a torus than a disk, it is wide enough (about two billion kilometers), to lodge one or two planets.
NB: Visible light is only a small range of electromagnetic vibrations found in the electromagnetic spectrum.
The infrared waves are wavelength located between the microwave and visible waves. Below the red, the wavelength of the infrared range between 780 nm and 1000 microns.
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Image: On April 12, 2012, the interferometer International Alma, after Hubble and Herschel observed the fascinating star Fomalhaut. The infrared image of the Herschel space telescope was taken in the 70 micron wavelength, Hubble has captured in the range of 0.5 microns and Alma in the range of 850 microns. It shows a beautiful disk of fifty billion kilometers, rotating around the star Fomalhaut, aged 250 million years.