One reason JUUL and vape pens are so popular among teens currently might be that they can be used indoors without attracting unwanted attention or creating a stench, Morean says. On Twitter, teens post about their usage in school.
What is a star's emission spectrum? It is the same as the HR diagram and gives the same information. It is the fingerprint of all of the colors of light emitted by a star. It is a graph of all the pollution given off by a star. It is a graph of the starâs solar flares.
Among the several different types of emission nebulae are H II regions, in which star formation is taking place and young, massive stars are the source of the ionizing photons; and planetary nebulae, in which a dying star has thrown off its outer layers, with the exposed hot core then ionizing them.