Message from radiation from space

What are the three types of spectra emitted from hot objects? How are spectral lines formed from hydrogen atoms? How are spectral lines formed from molecules? What kinds of information can we get from spectral lines? Emission spectra, Continuous Spectra, and absorption Spectra are the three kind of spectra emitted from the hot objects.The spectrum that is produced by a hot, thin gas is called Emission spectra. A spectra produced from hot and dense object is called Continuous Spectra, and the Absorption Spectra is a spectra formed from a hot dense object passing through cool and less dense gas. Spectral lines are created when hydrogen gas absorbs radiation from the bulb and release photons as the atoms switch through the excited stages. Spectral lines are also formed from molecules when there is a transition from one state to another. Observing spectral lines we can derive the elements, temperature and density of elements in the star. We can also find the mass and the size of the star. It also helps to know weather any magnetic field is coming from the stars or not.