Today I’ve released in my YouTube Channel the very first video of a series that seeks to connect professional astrophysics with amateur astronomy and outreach. This video, is entitled “Understanding the colours of the nebulae“, or why square brackets are important when naming metallic transitions in nebulae.
Do you know how profesional astrophysicists and amateur astronomers get vibrant colour images of nebulae? In this video I provide insights of the Physics behind these images. I emphasise why the ionic transitions of metallic elements (i.e., any element that is not hydrogen or helium) in nebulae must be written with brackets, as they are not recombination lines but collisional excited lines, that is, a kind of forbidden lines that only appear in extreme low-density gases because of the collision of ions with free electrons in the gas.
The video includes my subtitles in both English and Spanish.
An extended article about the video will be added here soon.
I hope you like it! And remember:
Dr Ángel R. López-Sánchez 