Explain this light and wavelength graph

Would someone please explain this graph. I am not an expert and with my limited understanding of physics, I am unable to correlate this graph between the light received with its wavelength.

I don't remember where exactly I found this; I was surfing online and came across it, and found it puzzling. Now I'm at a loss to find the original source. Can someone else recognize what's being illustrated here?

• Where is this from? Can you credit the source and provide a link? What is the context? Possibly using an exoplanet transit to look for sunspots on other stars? (1, 2, 3, 4) and youtu.be/hBU1yFbGHB8
– uhoh
Dec 6 '19 at 10:39
• In that case the word "Wavelength" might be an error, but it's hard to tell without the context. However, if it's from a crackpot site, then the question won't have a good answer. So please link to the original source and describe the context. Thanks!
– uhoh
Dec 6 '19 at 10:41
• @uhoh I don't remember from where I get this. I was surfing online and come across. Dec 6 '19 at 10:45
• It might relate to using the fine detail of the reduction in light from a transiting exoplanet in front of a spinning star to image starspots and similar. The general idea is that light from the side of the star spinning towards us is blue-shifted, and the other side red-shifted, so the effect of the planet on the exact shape of a spectral line from the star depends on which side of the star it's blocking and whether that bit of the star is "full brightness" or a starspot Dec 6 '19 at 12:27
• @SteveLinton I think if this were the case the graph would be comparing exoplanet's relative position in front of the star (x distance or time) to wavelength rather than "light" vs "wavelength". If the position of the planet plays a role in this animation, then there are too many data points for a line graph visualization (time/position, "light", wavelength) Dec 6 '19 at 15:01