Brown Dwarfs are Violet: A New Calculation of Human-eye Colors of Main-sequence Stars and Substellar Objects
Abstract
There has always been interest in the perceived colors of stars. They were key to the development of the Hertzsprung-Russell diagram, and they are also used widely in educational and public-outreach imagery. Thus, it is useful to develop tools to compute these colors from spectral energy distributions. This paper presents a collection of objective (CIE coordinate) and subjective (RGB triple) colors for main-sequence stars and brown dwarfs, as well as links to related codes and tables. Using the proposed conversion from CIE to RGB colors, O and B stars are bluer than equivalent blackbodies because of Paschen continuum absorption, and M dwarfs tend to be less red and more beige. Although brown dwarfs over a wide range of effective temperatures (400-2000 K) emit most of their flux in the infrared, their visible spectra are dominated by short wavelengths. Thus, they may appear violet to human eyes.
- Publication:
-
Research Notes of the American Astronomical Society
- Pub Date:
- September 2021
- DOI:
- 10.3847/2515-5172/ac225c
- Bibcode:
- 2021RNAAS...5..201C
- Keywords:
-
- Brown dwarfs;
- Late-type stars;
- Spectroscopy;
- Stellar atmospheres;
- Stellar colors;
- 185;
- 909;
- 1558;
- 1584;
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