B Are black holes white or monochromatic?

[newjerseyrunner]

I was asked if black holes are white today. I answered no, they're perfectly black to fit with classical physics since it's a high school kid who asked.

It did get me thinking about Hawking radiation though and I haven't been able to find an answer to my question online. Is Hawking radiation broadband or does it only emit photons at very specific energy levels?

 

[Drakkith]

I believe Hawking radiation approximates a blackbody, so a black hole would emit a broad range of wavelengths which would change as it gains or loses mass.

 

[phinds]

I believe Hawking radiation approximates a blackbody, so a black hole would emit a broad range of wavelengths which would change as it gains or loses mass.

That is my understanding as well.

 

[mathman]

Although it s radiation is approximately that of a black body, for any black hole more massive than our moon, the radiation temperature would be less than cosmic background.
https://en.wikipedia.org/wiki/Hawking_radiation