# What type of spectrum does the Wolf-Rayet star WR137 have?

Is it an Emission Spectra or an Absorption Spectra?

I think that it's an absorption spectrum, but then why is the light intensity curve focused on elements that should not be in the star in this case, like the carbon at position 4658?

PS: I do not study physics or astronomy or anything like that :)

• Have you looked at the Wikipedia article that uses the image? It should answer your question pretty directly. Jul 1 at 16:00
• @HDE226868 I was looking at the french version. Thank you. Jul 1 at 16:16
• The caption to the figure says, "Spectrum of WR 137 showing the prominent emission lines..." -- which should be a clue that it's an emission spectrum. (Which it is.) Jul 1 at 16:17
• These are emission lines. The units are Angstroms, not nm. Why do you think there is no carbon in a WR star? Jul 1 at 16:52
• @ProfRob The unit mistake was my bad! Jul 1 at 17:04

Wolf-Rayet stars are a complicated phenomenon. They are a class of stars that are broadly characterized as having little hydrogen in their spectra (i.e., the small emission line for H$$\alpha$$ in the OP's figure), and are dominated by strong emission lines corresponding to helium, nitrogen, carbon, and oxygen. The other trace elements in their spectra determine the type of WR star it is: nitrogen, carbon, or oxygen dominated, or some mixture.