07/09/2026
To ask "what color are the stars?" stretches objective truth, blurring into a philosophical debate. Most of them appear white to my unaided eyes, but are they?
Color is our physiobiological experience with the visible slice of the electromagnetic spectrum. Compared to other animals, our experience is quite good but still very limited. Other animals, such as birds and insects, also see ultraviolet slices of the electromagnetic spectrum. While others can see into the near infrared and even 'see' infrared light, as do pit vipers. Stars emit wavelengths far beyond any animal perception, but we don't call it 'color' as we're blind to it. We perceive color as the most abundant reflected visible wavelengths. For our own star, the Sun, the most abundant reflected visible wavelengths are green. Therefore, it might sound reasonable to say that the Sun is green, but it doesn't appear green to me. It usually appears yellowish to me, but with the recent wildfire smoke, I would call it red. In the absence of atmospheric filtering, the Sun appears as white as fresh snow. Indeed, snow is white because it is derived from white light reflecting and refracting from the white Sun (minus a slight shade of blue refracted from a blue sky).
Our Sun is fairly average in terms of size, color, and luminosity. But an average star is not necessarily the most common, as there is a great amount of size, color, and luminosity diversity amongst our neighboring stars. Astronomers standardize star color by their color temperature in degrees of Kelvin. Much like when a metal glows red, you know it's toasty, and when liquid metal glows white, it's very hot. Likewise, reddish stars are the coolest, while blue stars are immensely hot. Much to my dismay, many photographers still get color temperature confused.
Being diurnal, our vision is best suited for seeing color with high luminosity. As luminosity fades, as with the night sky, we can no longer discern wavelengths of light into individual colors, and our vision becomes grayscale, or 'panchromatic'. To our eyes, only the brightest night sky objects preserve their colors. But capturing these colorful objects with a camera is limited only by the exposure time and dark, clear skies. Most of the colorful objects trailing the frame are stars. But, look closely to see a few pinkish trails where hydrogen emission nebulae in the Milky Way core are also observed dancing across the sky with the stars. I began 'nebula trailing' one night a few winters ago, bored, with the Orion Nebula, and wondered if I could trail it. Sure enough, it works well with a full spectrum camera, and I'm surprised I haven't seen it done elsewhere.
Last Moonlight on the Monolith Featuring Startrails
